JP2009151411A - Data retrieval device, system, program and data retrieval method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow a data retrieval device that searches a database by means of a server/client configuration to respond as quickly as possible to a request from a client device for obtaining search results, while reducing the amount of resources consumed by the data retrieval device. <P>SOLUTION: A search execution request receiving unit 111 receives a search execution request 510, and a database managing unit 132 searches a database. The database managing unit 132 acquires all the records searched, a data conversion unit 141 converts data formats, and a look-ahead managing unit 142 stores the records in a look-ahead buffer 211. When a search result acquisition request receiving unit 121 receives a request 520 for acquiring search results, a search result transmission unit 122 transmits search results 620 by using the look-ahead buffer 211 as a transmission buffer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a data search apparatus for searching a database by a server / client configuration.

Log-only databases and mail archive databases can store large amounts of data, and there are variable-length and very large data types. When searching such a database, a large amount of resources of the data search device (server) is consumed from the time the database is opened until the database is closed.
In addition, if data is acquired from the database one by one after the client device is requested to acquire the search results, the resource consumption of the data search device can be suppressed, but a response to the acquisition request from the client is not received. Become slow.
Japanese Patent Laid-Open No. 2004-13758 JP 2006-260067 A JP 2007-11523 A Special table 2007-520812 JP 2007-65978 A

  The present invention has been made, for example, in order to solve the above-described problems, and it is an object of the present invention to reduce resource consumption of a data search apparatus and respond to an acquisition request from a client apparatus as quickly as possible.

A data search apparatus according to the present invention
In a data retrieval device that retrieves a database in response to a request from a client device,
Storage device for storing data, processing device for processing data, transmitting device for transmitting data, receiving device for receiving data, database storage unit, search execution request receiving unit, database management unit, data A conversion unit, a prefetch management unit, a search result acquisition request reception unit, and a search result transmission unit;
The database storage unit stores the database using the storage device,
The search execution request receiving unit receives a search execution request including data representing a search condition for searching the database from the client device using the receiving device,
The database management unit uses the processing device to change from the database stored in the database storage unit to the search condition based on the search condition represented by the data included in the search execution request received by the search execution request receiving unit. Search for matching data, and use the processing device to obtain the searched data from the database stored in the database storage unit,
The data conversion unit converts the data acquired by the database management unit into a format to be transmitted to the client device using the processing device,
The prefetch management unit stores the data converted by the data conversion unit using the storage device,
The search result acquisition request receiving unit receives, from the client device, a search result acquisition request including data representing the number of acquisition requests for data that the client device requests to acquire using the receiving device,
From the data stored in the prefetch management unit based on the number of acquisition requests represented by the data included in the search result acquisition request received by the search result acquisition request reception unit using the transmission device. The acquisition request count data is transmitted to the client device.

According to the data search device of the present invention, all the data searched by the database management unit is acquired, the data conversion unit converts the format, and the prefetch management unit stores it. Therefore, the search result acquisition request from the client device is received. You can close and disconnect the database without waiting. As a result, the resource of the data search apparatus 100 can be released and effectively used.
Further, since the prefetch management unit stores the data whose format has been converted by the data conversion unit, the storage area in which the prefetch management unit stores the data can be used as a transmission buffer by the search result transmission unit as it is. There is an effect that the response to the search result acquisition request becomes faster.

Embodiment 1 FIG.
The first embodiment will be described with reference to FIGS.

  FIG. 1 is a system configuration diagram showing an example of the overall configuration of a data search system 800 in this embodiment.

  The data search system 800 includes a client device 300 and a data search device 100. The client device 300 and the data search device 100 are connected via a network such as the Internet 940.

The client device 300 includes an application unit 301 and an interface unit 302. The client device 300 is a computer.
The application unit 301 provides various functions by executing application programs stored in the client device 300. The application unit 301 accesses a database stored in the data search device 100 via the interface unit 302.
The interface unit 302 relays access from the application unit 301 to the data search apparatus 100. The interface unit 302 makes a database search request to the data search device 100 in accordance with a request from the application unit 301.

The data search device 100 includes a server device 101, a database management device 102, and a database storage device 103.
The server apparatus 101 receives a search request from the client apparatus 300 and returns a search result to the client apparatus 300.
The database storage device 103 stores a database that receives access from the client device 300.
The database management device 102 manages the database stored in the database storage device 103. The database management device 102 searches the database stored in the database storage device 103 or returns the search result to the server device 101 in accordance with the search request received by the server device 101.
The data search device 100 may be physically one device, or the server device 101, the database management device 102, and the database storage device 103 may be independent devices.
Further, the server apparatus 101 and the client apparatus 300 may be physically one apparatus.

  FIG. 2 is a sequence diagram illustrating an example of a data flow in the data search system 800 according to this embodiment.

First, the client device 300 transmits a search execution request 510 to the data search device 100. Search execution request 510 is data requesting execution of search processing, and includes data representing search conditions.
The data search device 100 receives the search execution request 510 transmitted by the client device 300 and executes the requested search. After the search is completed, the data search device 100 transmits a search status 610 to the client device 300. The search status 610 is data for notifying the status of the search result. The status of the search result indicates, for example, data indicating whether the search has succeeded or failed, and if the search has failed, indicates the failure status (grammatical error in the search condition, unable to open the specified database, etc.) Data etc. are included. The data search apparatus 100 prepares for transmission of search results in preparation for a search result acquisition request from the client apparatus 300.
The client device 300 receives the search status 610 transmitted from the data search device 100, and determines whether or not the search is successful.

If the search is successful, the client device 300 transmits a search result acquisition request 520 to the data search device 100. The search result acquisition request 520 is data requesting to acquire the contents of the searched record, and includes data indicating the number of records to be acquired (hereinafter referred to as “number of acquisition requests”).
The data search apparatus 100 receives the search result acquisition request 520 transmitted by the client apparatus 300 and transmits the requested number of records as the search result 620. Thereafter, the data search device 100 performs post-transmission processing and prepares for the next transmission.
The client device 300 receives the search result 620 transmitted by the data search device 100 and acquires the searched record.

If the number of retrieved records is greater than the number of acquisition requests, records that have not been transmitted to the client device 300 remain. The client apparatus 300 can acquire all the searched records by transmitting the search result acquisition request 520 a plurality of times.
When the data included in one record is large or when the number of retrieved records is large, all the records retrieved by one transmission cannot be obtained, and the storage capacity of the client device 300 is small Will not be able to memorize all the records retrieved at once. For this reason, the client device 300 specifies the number of records to be acquired, acquires an appropriate number of records, and sequentially processes them. When the processing of the acquired record is completed, the client device 300 transmits the next search result acquisition request 520.

When the acquisition of all the searched records is completed or when it is desired to end the search in the middle of the acquisition, the client device 300 transmits a search end request 590 to the data search device 100.
The data search apparatus 100 receives the search end request 590 transmitted from the client apparatus 300 and transmits an acknowledgment 690 to the client apparatus 300. The understanding 690 is data indicating that the search end request 590 has been received. The data search apparatus 100 performs a search end process if necessary.

FIG. 3 is a diagram showing an example of the appearance of the server device 101, the database management device 102, the database storage device 103, and the client device 300 in this embodiment.
The server apparatus 101, the database management apparatus 102, the database storage apparatus 103, and the client apparatus 300 are a system unit 910, a display apparatus 901 having a CRT (Cathode / Ray / Tube) or LCD (liquid crystal) display screen, a keyboard 902 (Key. Board: K / B), mouse 903, FDD904 (Flexible / Disk / Drive), compact disc device 905 (CDD), printer device 906, scanner device 907, and other hardware resources, which are connected by cables and signal lines Has been.
The system unit 910 is a computer, and is connected to the facsimile machine 932 and the telephone 931 with a cable, and is connected to the Internet 940 via a local area network 942 (LAN) and a gateway 941.

FIG. 4 is a diagram illustrating an example of hardware resources of the server apparatus 101, the database management apparatus 102, the database storage apparatus 103, and the client apparatus 300 in this embodiment.
The server apparatus 101, the database management apparatus 102, the database storage apparatus 103, and the client apparatus 300 are also referred to as a CPU 911 (Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, processor that executes a program. ). The CPU 911 is connected to a ROM 913, a RAM 914, a communication device 915, a display device 901, a keyboard 902, a mouse 903, an FDD 904, a CDD 905, a printer device 906, a scanner device 907, and a magnetic disk device 920 via a bus 912, and the hardware thereof. Control the device. Instead of the magnetic disk device 920, a storage device such as an optical disk device or a memory card read / write device may be used.
The RAM 914 is an example of a volatile memory. The storage media of the ROM 913, the FDD 904, the CDD 905, and the magnetic disk device 920 are an example of a nonvolatile memory. These are examples of a storage device or a storage unit. The communication device 915 is an example of a transmission device and a reception device. A communication device 915, a keyboard 902, a scanner device 907, an FDD 904, and the like are examples of an input unit and an input device.
Further, the communication device 915, the display device 901, the printer device 906, and the like are examples of an output unit and an output device.

The communication device 915 is connected to a facsimile machine 932, a telephone 931, a LAN 942, and the like. The communication device 915 is not limited to the LAN 942, and may be connected to the Internet 940, a WAN (wide area network) such as ISDN, or the like. When connected to a WAN such as the Internet 940 or ISDN, the gateway 941 is unnecessary.
The magnetic disk device 920 stores an operating system 921 (OS), a window system 922, a program group 923, and a file group 924. The programs in the program group 923 are executed by the CPU 911, the operating system 921, and the window system 922.

The program group 923 stores programs that execute functions described as “˜units” in the description of the embodiments described below. The program is read and executed by the CPU 911.
The file group 924 includes information, data, signal values, variable values, and parameters that are described as “determination results of”, “calculation results of”, and “processing results of” in the description of the embodiments described below. Are stored as items of “˜file” and “˜database”. The “˜file” and “˜database” are stored in a recording medium such as a disk or a memory. Information, data, signal values, variable values, and parameters stored in a storage medium such as a disk or memory are read out to the main memory or cache memory by the CPU 911 via a read / write circuit, and extracted, searched, referenced, compared, Used for CPU operations such as calculation, calculation, processing, output, printing, and display. Information, data, signal values, variable values, and parameters are temporarily stored in the main memory, cache memory, and buffer memory during the CPU operations of extraction, search, reference, comparison, operation, calculation, processing, output, printing, and display. Is remembered.
In addition, the arrows in the flowcharts described in the following description of the embodiments mainly indicate input / output of data and signals. The data and signal values are the RAM 914 memory, the FDD 904 flexible disk, the CDD 905 compact disk, and the magnetic field. The data is recorded on a recording medium such as a magnetic disk of the disk device 920, another optical disk, a mini disk, and a DVD (Digital Versatile Disk). Data and signals are transmitted online via a bus 912, signal lines, cables, or other transmission media.

  In the description of the embodiments described below, what is described as “to part” may be “to circuit”, “to device”, and “to device”, and “to step” and “to”. “Procedure” and “˜Process” may be used. That is, what is described as “˜unit” may be realized by firmware stored in the ROM 913. Alternatively, it may be implemented only by software, only hardware such as elements, devices, substrates, wirings, etc., or a combination of software and hardware, and further a combination of firmware. Firmware and software are stored as programs in a recording medium such as a magnetic disk, a flexible disk, an optical disk, a compact disk, a mini disk, and a DVD. The program is read by the CPU 911 and executed by the CPU 911. That is, the program causes the computer to function as “to part” described below. Alternatively, the procedure or method of “to part” described below is executed by a computer.

  FIG. 5 is a block configuration diagram showing an example of the functional block configuration of each device constituting the data search system 800 in this embodiment.

The client device 300 includes a search execution request transmission unit 311, a search status reception unit 312, a search result acquisition request transmission unit 321, a search result reception unit 322, a search end request transmission unit 391, and an acknowledgment reception unit 392.
The search execution request transmission unit 311 transmits a search execution request 510 to the data search device 100 using the communication device 915.
The search status receiving unit 312 uses the communication device 915 to receive the search status 610 transmitted by the data search device 100.
The search result acquisition request transmission unit 321 transmits a search result acquisition request 520 to the data search device 100 using the communication device 915.
The search result receiving unit 322 receives the search result 620 transmitted by the data search device 100 using the communication device 915.
The search end request transmission unit 391 transmits a search end request 590 to the data search device 100 using the communication device 915.
The consent receiving unit 392 uses the communication device 915 to receive the consent 690 transmitted by the data search device 100.

The server apparatus 101 includes a search execution request reception unit 111, a search status transmission unit 112, a search result acquisition request reception unit 121, a search result transmission unit 122, a data conversion unit 141, a prefetch management unit 142, a management table management unit 147, and a search end. A request receiving unit 191, an acknowledgment transmitting unit 192, and a prefetch discarding unit 193 are included.
The database management apparatus 102 has a database management unit 132.
The database storage device 103 includes a database storage unit 131.

  The database storage unit 131 stores one or more databases in advance using the magnetic disk device 920.

The search execution request receiving unit 111 receives the search execution request 510 transmitted from the client device 300 using the communication device 915. The search execution request 510 includes data representing a search condition for searching the database stored in the database storage unit 131.
Using the CPU 911, the search execution request receiving unit 111 outputs a search condition represented by data included in the received search execution request 510.

The database management unit 132 uses the CPU 911 to input the search condition output by the search execution request receiving unit 111.
The database management unit 132 uses the CPU 911 to open (open) a database to be searched among the databases stored in the database storage unit 131 based on the input search condition.
The database management unit 132 uses the CPU 911 to search a record that matches the search condition from the opened database based on the input search condition.
The database management unit 132 uses the CPU 911 to output a search result (status).

The search status transmission unit 112 uses the CPU 911 to input the search result (status) output from the database management unit 132.
The search status transmission unit 112 uses the CPU 911 to generate a search status 610 including data representing the input status.
The search status transmission unit 112 transmits the generated search status 610 to the client device 300 using the communication device 915.

The database management unit 132 uses the CPU 911 to acquire all searched records from the opened database based on the input data. When a field to be transmitted is specified by the search condition, the database management unit 132 extracts only the field specified by the search condition from the fields constituting the record, and all the records that are searched You may get about.
The database management unit 132 uses the CPU 911 to output the acquired record.
The database management unit 132 uses the CPU 911 to close (close) the opened database.

The data conversion unit 141 uses the CPU 911 to input the record output from the database management unit 132.
The data conversion unit 141 uses the CPU 911 to convert the input record into a transmission format to be transmitted to the client device 300. For example, the data conversion unit 141 rearranges the data in the order in which the data is transmitted to the client device 300, converts the data into a character code to be transmitted to the client device 300, or converts the data into a byte order to be transmitted to the client device 300. Or convert.
Using the CPU 911, the data conversion unit 141 outputs a converted record (hereinafter referred to as “record data”).

The prefetch management unit 142 uses the CPU 911 to input the record data output from the data conversion unit 141.
The prefetch management unit 142 uses the RAM 914 to store the input record data.
The prefetch management unit 142 uses the RAM 914 in advance to reserve a storage area for storing record data (hereinafter referred to as “prefetch buffer 211”). The prefetch management unit 142 stores the input record data in the prefetch buffer 211 secured in advance.
Although the size of the prefetch buffer 211 secured by the prefetch management unit 142 varies depending on the capacity of the RAM 914 of the server apparatus 101, in this embodiment, all the record data output by the data conversion unit 141 is stored. A sufficient size can be secured.
Using the CPU 911, the prefetch management unit 142 uses a difference between the start address of the storage area in which the record data is stored in the prefetch buffer 211 and the start address of the prefetch buffer 211 (hereinafter referred to as “offset”), and prefetch The size of the storage area in which the record data is stored in the buffer 211 (hereinafter referred to as “data length”) is output.

Using the CPU 911, the management table management unit 147 inputs the offset and data length output by the prefetch management unit 142.
The management table management unit 147 uses the RAM 914 to store the input offset and data length.
The management table management unit 147 uses the CPU 911 in advance to secure a storage area (hereinafter referred to as “management table 212”) for storing the offset and the data length. The management table management unit 147 stores the input offset and data length in the management table 212 secured in advance.

The search result acquisition request receiving unit 121 receives the search result acquisition request 520 transmitted by the client device 300 using the communication device 915. The search result acquisition request 520 includes data representing the number of acquisition requests.
Using the CPU 911, the search result acquisition request receiving unit 121 outputs the number of acquisition requests represented by the data included in the received search result acquisition request 520.

The search result transmission unit 122 uses the CPU 911 to input the number of acquisition requests output by the search result acquisition request reception unit 121.
The search result transmission unit 122 uses the CPU 911 to read the offset and data length stored in the management table 212.
The search result transmitting unit 122 uses the CPU 911 to calculate the start address of the storage area in which the first record data to be transmitted in the prefetch buffer 211 is stored based on the read offset.
The search result transmitting unit 122 uses the CPU 911 to calculate the data length of the entire record data for the number of input acquisition requests based on the read data length.
The search result transmission unit 122 uses the communication device 915 to set the record data of the number of acquisition requests stored in the prefetch buffer 211 to the client device 300 as the search result 620 based on the calculated start address and data length. Send.
When the number of acquisition requests larger than the number of record data not yet transmitted to the client device 300 is designated, the search result transmission unit 122 uses the communication device 915 to record data that has not yet been transmitted. Send all.
When the maximum value of the data length that can be transmitted at one time is determined, the search result transmission unit 122 transmits the record data so that the calculated data length falls within the maximum value of the data length that can be transmitted at one time. Reduce the number of
Therefore, the number of record data transmitted by the search result transmission unit 122 is usually equal to the number of acquisition requests, but the search result transmission unit 122 may transmit a smaller number of record data than the number of acquisition requests.

The search end request receiving unit 191 receives the search end request 590 transmitted by the client device 300 using the communication device 915.
When the search end request receiving unit 191 receives the search end request 590, the approval transmitting unit 192 transmits the approval 690 to the client device 300 using the communication device 915.
When the search end request receiving unit 191 receives the search end request 590, the prefetch discard unit 193 deletes the offset and the data length stored in the management table 212.

  FIG. 6 is a diagram illustrating an example of a data format of data transmitted / received between the client device 300 and the data search device 100 in this embodiment.

The code part 501 is a part representing the type of data (discrimination of whether the data is a search execution request 510 or a search status 610).
The data part 502 is a part including data representing necessary information in accordance with the type of the data. Depending on the type of data, there may be no data portion 502.

  In the search execution request 510, the code part 501 is the search execution request code 511, and the data part 502 is the search condition data 512. Search execution request code 511 indicates that the data is search execution request 510. Search condition data 512 represents a search condition.

  In the search status 610, the code part 501 is the search status code 611, and the data part 502 is the search status data 612. Search status code 611 indicates that the data is search status 610. The search status data 612 represents the status of the search result.

  In the search result acquisition request 520, the code part 501 is the search result acquisition request code 521, and the data part 502 is the acquisition request number data 522. The search result acquisition request code 521 indicates that the data is a search result acquisition request 520. Acquisition request number data 522 represents the number of acquisition requests.

In the search result 620, the code part 501 is the search result code 621. Search result code 621 indicates that the data is search result 620.
The data portion 502 of the search result 620 includes a data header 622 and one or more record data 626. Data header 622 includes data representing the number and size of record data 626 included in data portion 502. The search result code 621 and the data header 622 are collectively referred to as header data 623.
The record data 626 is composed of one or more repetitions of a set of one field header 624 and one field data 625. The field header 624 includes data representing the length (size) of the field data 625 and the like. The field data 625 is data (converted into a transmission format) stored in the corresponding field of the retrieved record among the data stored in the database stored in the database storage unit 131.
Since the number of fields included in one record data and the name of each field are specified by the search condition, the search result 620 may not include such information. Alternatively, the data header 622 and the field header 624 may include data representing the number of fields and field names.

  In the search end request 590, the code portion 501 is the search end request code 591 and the data portion 502 is not present. The search end request code 591 indicates that the data is a search end request 590.

  In the understanding 690, the code part 501 is the consent code 691, and the data part 502 is not present. The consent code 691 indicates that the data is the consent 690.

  FIG. 7 is a flowchart showing an example of the flow of search processing in which the data search device 100 in this embodiment searches a database and result transmission processing in which the data search device 100 transmits search results.

The search process starts when the search execution request receiving unit 111 receives the search execution request 510.
In the search execution request receiving step S <b> 411, the search execution request receiving unit 111 receives the search execution request 510 transmitted by the client device 300 using the communication device 915. The search execution request receiving unit 111 outputs the search condition represented by the search condition data 512 included in the received search execution request 510.

In the database open step S412, the database management unit 132 uses the CPU 911 to search from the database stored in the database storage unit 131 based on the search condition output by the search execution request reception unit 111 in the search execution request reception step S411. Open the database to be searched.
In the data search step S413, the database management unit 132 uses the CPU 911 to search from the database opened in the database open step S412 based on the search condition output by the search execution request reception unit 111 in the search execution request reception step S411. Search for records that meet the conditions.
In the search status transmission step S414, the search status transmission unit 112 uses the communication device 915, and the search status 610 including the search status data 612 indicating the status of the search result obtained by the database management unit 132 searching the database in the data search step S413. Is transmitted to the client device 300.

  The processing from the data acquisition step S422 to the repetition step S427 is repeated for each record searched by the database management unit 132 in the data search step S413.

  In the data acquisition step S422, the database management unit 132 uses the CPU 911 to acquire the records searched in the data search step S413 one by one from the database opened in the database open step S412. When all the retrieved records are acquired and there are no more records that can be acquired, the process proceeds to the database closing step S428. When the record is acquired, the process proceeds to the data conversion process S423.

In the data conversion step S423, the data conversion unit 141 uses the CPU 911 to convert the record acquired by the database management unit 132 in the data acquisition step S422 to generate record data 626.
In the buffer writing step S425, the prefetch management unit 142 uses the RAM 914 to write and store the record data 626 generated by the data conversion unit 141 in the data conversion step S423 in the prefetch buffer 211.
In the repetition step S427, the process returns to the data acquisition step S422.

In the database closing step S428, the database management unit 132 uses the CPU 911 to close the database opened in the database opening step S412.
This completes the search process.

  The result transmission process starts when the search result acquisition request receiving unit 121 receives the search result acquisition request 520.

  In the search result acquisition request receiving step S431, the search result acquisition request receiving unit 121 receives the search result acquisition request 520 transmitted by the client device 300 using the communication device 915. Using the CPU 911, the search result acquisition request receiving unit 121 outputs the number of acquisition requests represented by the acquisition request number data 522 included in the received search result acquisition request 520.

In the search result transmission step S432, the search result transmission unit 122 is stored in the prefetch buffer 211 using the CPU 911 based on the number of acquisition requests output by the search result acquisition request reception unit 121 in the search result acquisition request reception step S431. A search result 620 is generated from the record data 626. The search result transmission unit 122 transmits the generated search result 620 to the client device 300 using the communication device 915.
Thus, the search result transmission process ends.

  FIG. 8 is a diagram schematically showing the operations of the data conversion unit 141, the prefetch management unit 142, and the search result transmission unit 122 in this embodiment.

  The data conversion unit 141 uses the CPU 911 to convert the record, and generates record data in the same format as the record data 626 included in the search result 620. In other words, the data conversion unit 141 uses the CPU 911 to generate the field data 625 by converting the character code and byte order of the field data for each field to be transmitted to the client device 300, and the generated field Based on the data 625, a field header 624 including data representing the length of the field data 625 and the like is generated. Using the CPU 911, the data conversion unit 141 combines the generated field header 624 and field data 625 to generate record data 626.

The prefetch management unit 142 stores the record data 626 generated by the data conversion unit 141 in the prefetch buffer 211 using the RAM 914.
The prefetch buffer 211 has a first-in first-out structure, and the search result transmission unit 122 can read and transmit the record data 626 while the prefetch management unit 142 writes the record data 626 to the prefetch buffer 211.
If the search result acquisition request receiving unit 121 does not receive the search result acquisition request 520 from the client device 300, the search result transmission unit 122 does not transmit the record data 626, but has the search result transmission unit 122 transmitted the record data 626? Regardless of whether or not, the data conversion unit 141 sequentially generates record data 626 for all the retrieved records, and the prefetch management unit 142 writes the generated record data 626 into the prefetch buffer 211. That is, without waiting for a request from the client device 300 side, the prefetch management unit 142 stores the data converted into the transmission format by the data conversion unit 141 in the prefetch buffer 211 for all the retrieved records.

  In the database management apparatus 102, in order to open the database stored in the database storage unit 131 for searching, resources such as a memory are required for managing the tables and transactions in the database. In particular, when a data type having a variable length and a very large size exists in the database, a large amount of resources of the database management apparatus 102 are consumed.

  In this embodiment, the database management unit 132 closes the database as soon as all retrieved records are acquired. Therefore, the resource of the database management apparatus 102 consumed for opening the database can be immediately released.

The data search device 100 in this embodiment is a data search device 100 that searches a database in response to a request from the client device 300.
The data search device 100 receives data from a storage device (RAM 914, magnetic disk device 920) that stores data, a processing device (CPU 911) that processes data, a transmission device (communication device 915) that transmits data, and the like. A receiving device (communication device 915), a database storage unit 131, a search execution request receiving unit 111, a database management unit 132, a data conversion unit 141, a prefetch management unit 142, a search result acquisition request receiving unit 121, And a search result transmission unit 122.
The database storage unit 131 stores the database using the storage device (magnetic disk device 920).
Using the receiving device (communication device 915), the search execution request receiving unit 111 receives from the client device 300 a search execution request 510 including data (search condition data 512) representing search conditions for searching the database. It is characterized by doing.
The database management unit 132 uses the processing device (CPU 911), based on the search condition represented by the data (search condition data 512) included in the search execution request 510 received by the search execution request receiving unit 111. A database in which the database storage unit 131 stores data (record) that matches the search condition and stores the searched data (record) in the database storage unit 131 using the processing device (CPU 911). It is acquired from.
The data conversion unit 141 converts the data (record) acquired by the database management unit 132 into a format to be transmitted to the client device 300 using the processing device (CPU 911).
The prefetch management unit 142 stores data (record data 626) converted by the data conversion unit 141 using the storage device (RAM 914).
The search result acquisition request reception unit 121 uses the reception device (communication device 915) to indicate data (acquisition request number data 522) indicating the number of acquisition requests for data (record data 626) that the client device 300 requests to acquire. ) Including a search result acquisition request 520 including the client device 300.
The search result transmission unit 122 uses the transmission device (communication device 915) to obtain the data (acquisition request number data 522) included in the search result acquisition request 520 received by the search result acquisition request reception unit 121. Based on the number of requests, the acquisition request number data (record data 626) is transmitted to the client device 300 from the data (record data 626) stored by the prefetch management unit 142.

  According to the data search device 100 in this embodiment, all the data searched by the database management unit 132 is acquired, the data conversion unit 141 converts the format, and the prefetch management unit 142 stores the data. The database can be closed and disconnected without waiting for the search result acquisition request 520. As a result, the resource of the database management apparatus 102 can be released and effectively used.

The data search system 800 (system) in this embodiment includes a client device 300 and a data search device 100.
The client device 300 includes a transmission device (communication device 915) that transmits data, a reception device (communication device 915) that receives data, a search execution request transmission unit 311, a search result acquisition request transmission unit 321, and a search And a result receiving unit 322.
The search execution request transmission unit 311 transmits the search execution request 510 to the data search device 100 using the transmission device (communication device 915).
The search result acquisition request transmission unit 321 transmits the search result acquisition request 520 to the data search device 100 using the transmission device (communication device 915).
The search result receiving unit 322 receives the data transmitted by the search result transmitting unit 122 using the receiving device (communication device 915).

  According to the data search system 800 in this embodiment, the client device 300 does not receive all search results, but specifies the number of requests for acquisition and requests the data search device 100 to acquire search results. Therefore, it is not necessary for the client device 300 to hold all the search results, and it is possible to acquire and process little by little. As a result, even when the number of search results is large or when one piece of data is very large, it is possible to prevent the resources of the client device 300 from being compressed.

  The data search device 100 in this embodiment can be realized by causing a computer to execute a program that functions as the data search device 100.

  According to the program that implements the data search apparatus 100 in this embodiment, all data searched by the database management unit 132 is acquired, the data conversion unit 141 converts the format, and the prefetch management unit 142 stores the data. The data search apparatus 100 that can close and disconnect the database without waiting for the search result acquisition request 520 from the client apparatus 300 can be realized. Thereby, there is an effect that the resources of the computer functioning as the database management apparatus 102 can be released and effectively used.

A data search method in which the data search device 100 in this embodiment searches a database in response to a request from a client device is a storage device (RAM 914, magnetic disk device 920) for storing data and a processing device (CPU 911) for processing data. ), A transmitting device (communication device 915) for transmitting data, and a receiving device (communication device 915) for receiving data, perform the following steps.
The receiving device (communication device 915) receives from the client device 300 a search execution request 510 including data (search condition data 512) representing a search condition for searching the database.
The processing device (CPU 911) searches the database for data (record) that matches the search condition based on the search condition represented by the data (search condition data 512) included in the received search execution request 510.
The processing device (CPU 911) acquires the retrieved data (record) from the database.
The processing device (CPU 911) converts the acquired data (record) into a format to be transmitted to the client device 300.
The storage device (RAM 914) stores the converted data (record data 626).
The receiving device (communication device 915) sends a search result acquisition request 520 including data (acquisition request number data 522) indicating the acquisition request number of data (record) that the client device 300 requests acquisition to the client device 300. Receive from.
Based on the number of acquisition requests indicated by the data (acquisition request count data 522) included in the received search result acquisition request 520, the transmission device (communication device 915) uses the acquisition request from the stored data (record data 626). Number data (record data 626) is transmitted to the client device 300.

  According to the data search method in this embodiment, all the searched data is acquired, converted in format, and stored. Therefore, without waiting for the search result acquisition request 520 from the client device 300, the database is closed, Can be separated. Thereby, there is an effect that resources necessary to keep the database open can be released and effectively used.

The data retrieval method described above includes a database client (client device 300) that accesses a database, and a database management unit (database management device 102) that retrieves data in response to an access request (such as a search execution request 510) from the database client. And a data search system 800 (database system) having a database server (server apparatus 101) having a data storage area.
In response to a search execution request 510 from the database client (client device 300), the prefetch buffer 211 stores data that has been prefetched by the database server in an arrangement that can be used as communication data.
The management table 212 enables the database server (server apparatus 101) to use the prefetch buffer 211 as communication data.
The database server (server device 101) converts the prefetched data into a communication data format (transmission format) and stores it in the prefetch buffer 211, creates a management table 212, and retrieves a search result from the database client (client device 300). The communication buffer address is determined by the management table 212 with the acquisition request 520.

  According to the data search method described above, the database data can be prefetched asynchronously with the search request from the client (client device 300), and the database can be closed. As a result, in the search from the client (client device 300), the search result is not obtained until the end, but it is left on the way, or a search request is issued from a plurality of clients (client device 300). However, the resources (resources) of the data search device 100 are not tight. This is especially true for databases that have a variable length and very large data types, such as log-only databases and mail archive databases, and that consume a large amount of server resources during database opening and closing. This is noticeable when searching. As a result, in order to strengthen security measures such as internal information leakage problems and compliance with the Personal Information Protection Law, a database that can store large volumes of data and handle a wide variety of data in different formats It can be operated.

The data search system 800 (database system) described above includes a database client (client device 300) that accesses the database, and a database management unit (data search request 510 or the like) that receives data from the database client and searches for data. Database management apparatus 102) and a database server (server apparatus 101) having a data storage area.
In response to the search execution request 510 from the database client (client apparatus 300), the database server (server apparatus 101) stores all the prefetched data in the database server in an arrangement that can be used as communication data. When,
A management table 212 that enables the prefetch buffer 211 to be used as communication data;
The prefetched data is converted into a communication data format (transmission format) and stored in the prefetch buffer 211, and the management table 212 is created, and the search result acquisition request 520 from the database client (client device 300) communicates with the management table 212. A buffer management unit (search result transmission unit 122) for determining a buffer address.

  According to the data search system 800 described above, it is possible to prefetch all the data up to the final data instead of prefetching from the database only the data for the number of items scheduled to be transmitted to the communication buffer at a time. As a result, there is a data type of variable length and very large size, and in a database system that consumes a large amount of server resources from opening to closing of the database along with the search, a search request (search) from the client (client device 300) For all execution requests 510), it is possible to perform prefetch processing for all cases and to use the prefetch buffer 211 as a communication buffer in order to maintain the transfer performance of search results.

Embodiment 2. FIG.
The second embodiment will be described with reference to FIGS.
Since the system configuration and functional block configuration of the data search system 800 in this embodiment are the same as those described in the first embodiment, description thereof is omitted here.

  In this embodiment, a case where the prefetch management unit 142 cannot secure a sufficiently large prefetch buffer 211 will be described.

  FIG. 9 is a diagram illustrating an example of a detailed block configuration of the prefetch management unit 142 and a data structure of the prefetch buffer 211 and the like in this embodiment.

The prefetch management unit 142 includes a prefetch buffer management unit 143 and a prefetch file management unit 144.
The prefetch buffer management unit 143 determines whether or not the prefetch buffer 211 is empty. If the prefetch buffer 211 determines that the prefetch buffer 211 is empty, the RAM 914 is used to record the record data 626 generated by the data conversion unit 141. Store in the free area of the prefetch buffer 211. When it is determined that there is no free space in the prefetch buffer 211, the prefetch buffer management unit 143 stores the record data 626 generated by the data conversion unit 141 in the prefetch file 221 using the magnetic disk device 920.

  Both the prefetch buffer 211 and the prefetch file 221 are storage areas for storing record data 626. The difference between the prefetch buffer 211 and the prefetch file 221 is a storage area in which the prefetch buffer 211 uses the RAM 914 (first storage device) to store record data 626 that has not yet been transmitted to the client device 300. On the other hand, the prefetch file 221 is a storage area for storing record data 626 that has not yet been written to the prefetch buffer 211 using the magnetic disk device 920 (second storage device). As is widely known, the magnetic disk device 920 takes a longer time to write and read data than the RAM 914. The RAM 914 has a higher unit price per unit storage capacity than the magnetic disk device 920. For this reason, even if the server device 101 does not have a sufficiently large RAM 914 and a sufficiently large prefetch buffer 211 cannot be secured, the magnetic disk device 920 stores a sufficiently large prefetch file 221. be able to.

  The prefetch file management unit 144 uses the CPU 911 to determine whether record data 626 that has not yet been written in the prefetch buffer 211 is stored in the prefetch file 221. Further, the prefetch file management unit 144 uses the CPU 911 to determine whether or not the prefetch buffer 211 has an empty space. When the prefetch file management unit 144 determines that the record data 626 that has not yet been written in the prefetch buffer 211 is stored in the prefetch file 221 and that the prefetch buffer 211 has a free space, the record data 626 from the prefetch file 221 is recorded. And the read record data 626 is stored in an empty storage area of the prefetch buffer 211 using the RAM 914.

  The management table management unit 147 uses the RAM 914 to store the offset 711 and the data length 712 of the record data 626 stored in the prefetch buffer 211 by the prefetch buffer management unit 143 and the prefetch file management unit 144 in the management table 212.

  The prefetch buffer management unit 143 stores the record data 626 generated by the data conversion unit 141 in the prefetch buffer 211, so that the prefetch buffer 211 becomes full. The prefetch buffer management unit 143 stores the remaining record data 626 in the prefetch file 221. Thereafter, when the search result transmission unit 122 transmits the record data 626 stored in the prefetch buffer 211, the prefetch buffer 211 is vacant. The prefetch file management unit 144 reads the record data 626 from the prefetch file 221 and stores it in the free area of the prefetch buffer 211.

In advance, the prefetch buffer management unit 143 uses the CPU 911 to secure a storage area having consecutive addresses in the RAM 914 to serve as the prefetch buffer 211.
Using the CPU 911, the prefetch buffer management unit 143 manages the prefetch buffer 211 as a set of storage areas that are circularly ordered. That is, the prefetch buffer management unit 143 manages a certain storage area in the prefetch buffer 211 as a storage area next to the storage area of the previous address, and uses the first storage area of the prefetch buffer 211 as the end of the prefetch buffer 211. Is managed as the next storage area.

The prefetch buffer management unit 143 and the prefetch file management unit 144 use the RAM 914 to store the record data 626 using one or more continuous storage areas of the prefetch buffer 211. The prefetch buffer management unit 143 and the prefetch file management unit 144 use the CPU 911 to calculate the offset 711 and the data length 712 of the record data 626 stored in the prefetch buffer 211, and the management table management unit 147 uses the RAM 914 to Store in the management table 212.
Using the CPU 911, the prefetch buffer management unit 143 and the prefetch file management unit 144 use the CPU 911 based on the offset 711 and the data length 712 stored in the management table 212 to finally store the last address ( Or offset). In addition, the prefetch buffer management unit 143 and the prefetch file management unit 144 use the CPU 911, based on the offset 711 and the data length 712 stored in the management table 212, for the first time that the search result transmission unit 122 has not yet transmitted. The first address (or offset) of the record data 626 is calculated. The prefetch buffer management unit 143 and the prefetch file management unit 144 use the CPU 911 to calculate the size of the free area of the prefetch buffer 211 based on the two calculated addresses (or offsets). The prefetch buffer management unit 143 and the prefetch file management unit 144 use the CPU 911 to calculate the data length of the next record data 626. The prefetch buffer management unit 143 and the prefetch file management unit 144 use the CPU 911 to compare the calculated free space size with the calculated data length, and when the free space size is smaller than the data length, It is determined that there is no space in the prefetch buffer 211.

  When the search result transmission unit 122 transmits the search result 620, the CPU 911 is used to delete the offset 711 and the data length 712 for the record data 626 included in the transmitted search result 620 from the management table 212. Accordingly, the prefetch buffer management unit 143 and the prefetch file management unit 144 recognize the storage area in the prefetch buffer 211 that stores the record data 626 that has already been transmitted as a free area.

FIG. 10 is a flowchart showing an example of the flow of search processing in which the data search device 100 in this embodiment searches the database and result transmission processing in which the data search device 100 transmits the search result.
Note that portions common to the search processing and result transmission processing described in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted here.

In the search process, after the data conversion step S423 is completed, the process proceeds to the empty determination step S424.
In the empty determination step S424, the prefetch buffer management unit 143 uses the CPU 911 to determine whether or not there is an empty in the prefetch buffer 211. If it is determined that the prefetch buffer 211 is empty, the process proceeds to the buffer writing step S425. If it is determined that there is no space in the prefetch buffer 211, the process proceeds to the file writing step S426.

  In the buffer writing step S425, the prefetch buffer management unit 143 uses the RAM 914 to store the record data 626 generated by the data conversion unit 141 in the data conversion step S423 in the prefetch buffer 211. Then, it progresses to repetition process S427.

  In the file writing step S426, the prefetch buffer management unit 143 stores the record data 626 generated by the data conversion unit 141 in the data conversion step S423 in the prefetch file 221 using the magnetic disk device 920. Then, it progresses to repetition process S427.

In the result transmission process, after the search result transmission step S432 is completed, the process proceeds to the empty determination step S441.
In the empty determination step S441, the prefetch file management unit 144 uses the CPU 911 to determine whether or not there is an empty in the prefetch buffer 211. If it is determined that the prefetch buffer 211 is empty, the process proceeds to the data reading step S442. If it is determined that there is no space in the prefetch buffer 211, the result transmission process is terminated.
In the data reading step S442, the prefetch file management unit 144 uses the CPU 911 to read one record data 626 stored in the prefetch file 221. When all record data 626 stored in the prefetch file 221 is read and there is no record data 626 that can be read, the result transmission process is terminated. When the record data 626 is read, the process proceeds to the data writing process S443.
In the data writing step S443, the prefetch file management unit 144 uses the RAM 914 to store the record data 626 read in the data read step S442 in the prefetch buffer 211.
In the repetition step S444, the process returns to the empty determination step S441.

The data search device 100 in this embodiment has two or more storage devices (RAM 914, magnetic disk device 920).
Of the storage devices, the second storage device (magnetic disk device 920) has a longer time for writing and reading data than the first storage device (RAM 914) of the storage devices. To do.
The prefetch management unit 142 includes a prefetch buffer management unit 143 and a prefetch file management unit 144.
The prefetch buffer management unit 143 secures a storage area (prefetch buffer 211) for storing data using the first storage device (RAM 914) and secures a storage area using the processing device (CPU 911). The data conversion unit 141 uses the first storage device (RAM 914) to determine whether or not the reserved storage area is free. 626) is stored in a free storage area, and when it is determined that there is no free storage area, the data conversion unit 141 converts the data using the second storage device (magnetic disk device 920). Data (record data 626) is stored (in the prefetch file 221).
The prefetch file management unit 144 has data (record data 626) stored by the prefetch buffer management unit 143 using the second storage device (magnetic disk device 920) using the processing device (CPU 911). The prefetch buffer management unit 143 determines that there is data (record data 626) stored using the second storage device (magnetic disk device 920). It is determined whether or not the storage area (prefetch buffer 211) secured by 143 has a free space, and when it is determined that the storage area (prefetch buffer 211) secured by the prefetch buffer management unit 143 has a free space, Using the one storage device (RAM 914), the prefetch buffer management unit 143 uses the second storage device (magnetic device). And to store in the storage area is empty and the data (record data 626) stored using a disk device 920).
The search result transmission unit 122 uses the transmission device (communication device 915) and the data (record data 626) stored by the prefetch management unit 142 using the first storage device (RAM 914). It transmits to 300, It is characterized by the above-mentioned.

  According to the data search device 100 in this embodiment, even if the prefetch management unit 142 cannot secure a prefetch buffer 211 having a large enough size to store all the record data 626 generated by the data conversion unit 141, the prefetching is performed. Since the management unit 142 stores the record data 626 in the prefetch file 221 using the second storage device, the database can be closed and disconnected without waiting for the search result acquisition request 520 from the client device 300. . As a result, the resource of the database management apparatus 102 can be released and effectively used.

  In this embodiment, the configuration using the RAM 914 as an example of the first storage device and the magnetic disk device 920 as an example of the second storage device has been described. However, the first storage device, the second storage device, As long as the first storage device has a shorter read / write time and the second storage device has a larger capacity, other combinations may be used. For example, the first storage device may be a cache memory and the second storage device may be a RAM 914, the first storage device may be a cache memory or a RAM 914, and the second storage device may be a USB (Universal Serial Bus). It may be a memory, a magnetic disk device 920, an optical disk device, or the like.

The data search apparatus 100 in this embodiment further includes a management table management unit 147.
The prefetch management unit 142 secures a plurality of ordered storage areas (prefetch buffer 211) using the storage device (RAM 914), and the data conversion unit 141 uses the storage device (RAM 914) to perform conversion. The recorded data (record data 626) is stored in a reserved storage area (prefetch buffer 211).
The management table management unit 147 uses the storage device (RAM 914) to store data (offset 711, data length 712) representing a storage area in which the prefetch management unit 142 stores data (record data 626). It is characterized by.
The search result transmission unit 122 uses the transmission device (communication device 915) to store data (record data) stored in the storage area indicated by the data (offset 711, data length 712) stored by the management table management unit 147. 626) is transmitted to the client apparatus 300.

  According to the data search device 100 in this embodiment, since the management table management unit 147 stores data representing the storage area in which the prefetch management unit 142 stores data in the management table 212, the search result transmission unit 122 manages the data. Based on the table 212, it can be known where in the prefetch buffer 211 the data to be transmitted is stored. As a result, the search result transmission unit 122 can use the prefetch buffer 211 as a transmission buffer.

  The management table management unit 147 does not have to store the data stored in the management table 212 as the offset 711 and the data length 712. For example, using the RAM 914, the management table management unit 147 uses the RAM 914 to indicate data (write pointer) indicating the start address of the free area, data (read pointer) indicating the start address of data to be transmitted next, and each record data 626. Data length 712 and the offset 711 need not be stored.

  The data search method described above uses a prefetch file (prefetch file 221) for storing data (record data 626) that cannot be stored in the prefetch buffer 211 on the memory (RAM 914).

  The data search apparatus 100 described above includes a prefetch file (prefetch file 221) for storing data (record data 626) that cannot be stored in the prefetch buffer 211 on the memory (RAM 914).

Embodiment 3 FIG.
A third embodiment will be described with reference to FIGS.
Since the system configuration and functional block configuration of the data search system 800 in this embodiment are the same as those described in the first embodiment or the second embodiment, description thereof is omitted here.

  In this embodiment, a specific example of an operation in which the search result transmission unit 122 transmits the search result 620 will be described.

The prefetch management unit 142 uses the RAM 914 to secure the prefetch buffer 211.
The prefetch management unit 142 uses the CPU 911 to free a storage area of a predetermined number of bytes (hereinafter referred to as “header length”) from the beginning of the secured prefetch buffer 211 and use it as a header storage area. Using the RAM 914, the prefetch management unit 142 stores the record data 626 generated by the data conversion unit 141 in order from the header storage area.

The search result transmission unit 122 uses the CPU 911 to generate header data 623 to be added to data to be transmitted to the client device 300. The header data 623 generated by the search result transmission unit 122 includes the search result code 621 and the data header 622 as described in the first embodiment. Further, the length of the header data 623 generated by the search result transmitting unit 122 is constant and equal to the header length.
Using the CPU 911, the search result transmission unit 122 reads the offset 711 and the data length 712 stored in the management table 212 by the management table management unit 147. Using the CPU 911, the search result transmission unit 122 calculates the start address of the earliest record data 626 to be transmitted to the client device 300 based on the read offset 711.
Using the RAM 914, the search result transmission unit 122 stores the generated header data 623 in the header length storage area (hereinafter referred to as “header storage area 721”) before the calculated start address.
The search result transmission unit 122 uses the CPU 911 to calculate the length of the entire search result 620 to be transmitted to the client device 300 based on the read data length 712.
The search result transmission unit 122 uses the communication device 915 to send the header data 623 stored in the prefetch buffer 211 and one or more record data 626 stored in the storage area following the header data 623 to the client device 300. To send.

  FIG. 11 is a flowchart showing an example of the flow of the search result transmission step S432 in which the search result transmission unit 122 transmits the search result 620 in this embodiment.

In the header data generation step S451, the search result transmission unit 122 generates the header data 623 using the CPU 911.
In the transmission position calculation step S452, the search result transmission unit 122 uses the CPU 911 to read the offset 711 and the data length 712 stored in the management table 212 by the management table management unit 147. Using the CPU 911, the search result transmission unit 122 calculates the start address of the earliest record data 626 to be transmitted to the client device 300 based on the read offset 711. The search result transmission unit 122 uses the CPU 911 to calculate a start address (hereinafter referred to as “transmission position 731”) of the header storage area 721 by subtracting a predetermined header length from the calculated start address.
In the header data writing step S453, the search result transmission unit 122 uses the RAM 914 to store the header data generation step S451 in the header storage area 721 starting from the transmission position 731 calculated in the transmission position calculation step S452 in the prefetch buffer 211. The header data generated in is stored.
In the transmission length calculation step S454, the search result transmission unit 122 uses the CPU 911 to calculate the data length of the record data 626 to be transmitted to the client device 300 based on the data length 712 read in the transmission position calculation step S452. Sum up. The search result transmission unit 122 adds the header length to the total data length, and calculates the total length of the record data 626 to be transmitted to the client device 300 (hereinafter referred to as “transmission length 732”).
In the buffer transmission step S455, the search result transmission unit 122 uses the communication device 915 to start from the transmission position 731 calculated in the transmission position calculation step S452 in the prefetch buffer 211, and to calculate the transmission calculated in the transmission length calculation step S454. The storage area for the length is used as it is as a transmission buffer, and the data stored in the transmission buffer is transmitted to the client apparatus 300 as a search result 620.

  FIG. 12 is a diagram illustrating an example of a data structure of the prefetch buffer 211 and the like in this embodiment.

  The prefetch buffers 211a to 211f represent the state of the prefetch buffer 211 at a certain point in time.

Using the CPU 911, the prefetch management unit 142 frees a header length storage area from the top of the prefetch buffer 211 and sets it as a header storage area 721. Using the RAM 914, the prefetch management unit 142 stores the first record data 626a in a storage area starting from the header storage area 721.
For the second and subsequent record data 626b and 626c, the prefetch management unit 142 uses the RAM 914 to store the record data 626b and 626c in the storage area starting from the next record data 626a and 626b, respectively. Remember. The prefetch buffer 211a is the state of the prefetch buffer 211 at this time.
In this example, the storage area secured as the prefetch buffer 211 is small, and the prefetch management unit 142 uses the CPU 911 to store the free area 722 of the prefetch buffer 211 in the record data 626d when trying to store the next record data 626d. Assume that it is determined that the length is smaller than the data length. The prefetch management unit 142 uses the magnetic disk device 920 to store the remaining record data 626 in the prefetch file 221. Note that the header storage area 721 is not included in the free area 722.
Also, the management table management unit 147 has three sets of offsets 711a to 711c and data lengths 712a to 712c corresponding to each of the three record data 626a to 626c stored in the prefetch buffer 211 by the prefetch management unit 142, and the RAM 914. And stored in the management table 212.

When the search result acquisition request reception unit 121 receives the search result acquisition request 520, the search result transmission unit 122 generates the header data 623a using the CPU 911. The header data 623a is data added to the head of the data that the search result transmission unit 122 transmits to the client device 300, and includes the search result code 621 and the data header 622 as described in the first embodiment.
Using the CPU 911, the search result transmission unit 122 reads the offset 711a corresponding to the earliest record data 626a among the offsets 711 stored in the management table 212. Using the CPU 911, the search result transmission unit 122 calculates the transmission position 731 by subtracting the length of the header storage area 721 from the read offset 711a.
Using the RAM 914, the search result transmission unit 122 stores the generated header data 623a in the header storage area 721 starting from the calculated transmission position 731. The prefetch buffer 211b is the state of the prefetch buffer 211 at this time.
The search result transmission unit 122 uses the CPU 911 to calculate the transmission length 732. In this example, it is assumed that the acquisition request number represented by the acquisition request number data 522 included in the search result acquisition request 520 received by the search result acquisition request receiving unit 121 is “2”. The search result transmission unit 122 uses the CPU 911 to read the data lengths 712a and 712b corresponding to the first record data 626a and the second record data 626b among the data lengths 712 stored in the management table 212, respectively. . Using the CPU 911, the search result transmission unit 122 adds the read data lengths 712a and 712b, and further adds the length of the header storage area 721 to calculate the transmission length 732.

  The search result transmission unit 122 uses the prefetch buffer 211 as a transmission buffer based on the calculated transmission position 731 and transmission length 732 using the communication device 915, and transmits data with a transmission length 732 starting from the transmission position 731. The search result 620 is transmitted to the client device 300.

Using the CPU 911, the search result transmission unit 122 deletes the offsets 711a and 711b and the data lengths 712a and 712b corresponding to the transmitted record data 626a and 626b from the management table 212.
The prefetch management unit 142 uses the CPU 911 to read from the management table 212 the offset 711c corresponding to the earliest record data 626c stored in the prefetch buffer 211 at this time. Using the CPU 911, the prefetch management unit 142 sets a header length storage area that ends before the read offset 711c as a header storage area 721. The prefetch management unit 142 calculates the last address of the free area 723 assuming that the storage area before the header storage area 721 is the last of the free areas 723.
Also, the prefetch management unit 142 uses the CPU 911 to read from the management table 212 the offset 711c and the data length 712c corresponding to the last record data 626c stored in the prefetch buffer 211 at this time. The prefetch management unit 142 uses the CPU 911 to calculate the first address of the free area 722, assuming that the storage area next to the storage area having the data length 712c is the first of the free areas 722 after the read offset 711c. .
Using the CPU 911, the prefetch management unit 142 calculates the size of the free area 722 from the calculated first address of the free area 722 and the last address of the prefetch buffer 211, and calculates the first address of the prefetch buffer 211. The size of the free area 723 is calculated from the last address of the free area 723.

  The prefetch management unit 142 uses the CPU 911 to read the next record data 626d stored in the prefetch file 221. The prefetch management unit 142 uses the CPU 911 to compare the data length of the read record data 626d with the calculated size of the free area 722, and the size of the free area 722 is smaller. It is determined that the record data 626d cannot be stored. Next, the prefetch management unit 142 uses the CPU 911 to compare the data length of the read record data 626d with the calculated size of the free area 723, and the size of the free area 723 is larger. It is determined that there is a space in 211. Using the RAM 914, the prefetch management unit 142 stores the read record data 626d in the free area 723 of the prefetch buffer 211. Using the CPU 911, the prefetch management unit 142 calculates the size of the remaining free space by subtracting the data length of the record data 626d from the calculated size of the free space 723.

  The prefetch management unit 142 divides the record data 626d into two, assuming that the empty area 723 continues after the empty area 722, stores a part in the empty area 722, and stores the rest in the empty area 723. You may remember.

The prefetch management unit 142 uses the CPU 911 to read the next record data 626e stored in the prefetch file 221. The prefetch management unit 142 uses the CPU 911 to compare the data length of the read record data 626e with the size of the remaining free space, and the size of the free space is larger. The RAM 914 is used to determine that the read record data 626e is stored in a storage area starting from the next of the previous record data 626d in the empty area 723 of the prefetch buffer 211. The prefetch management unit 142 uses the CPU 911 to calculate the size of the remaining free area. The prefetch buffer 211d is in the state of the prefetch buffer 211 at this time.
Similarly, until the prefetch management unit 142 determines that there is no space in the prefetch buffer 211 or until the record data 626 stored in the prefetch file 221 is exhausted, the prefetch management unit 142 records the record data 626 from the prefetch file 221. Are stored in the free area of the prefetch buffer 211.

When the search result acquisition request reception unit 121 receives the search result acquisition request 520, the search result transmission unit 122 generates the header data 623b using the CPU 911. The search result transmission unit 122 uses the CPU 911 to read the offset 711c corresponding to the earliest record data 626c at this time from the offset 711 stored in the management table 212 by the management table management unit 147, and uses the CPU 911. Based on the read offset 711c, the transmission position 731 is calculated. Using the RAM 914, the search result transmission unit 122 stores the generated header data 623b in the header storage area 721 starting from the calculated transmission position 731. The prefetch buffer 211e is in the state of the prefetch buffer 211 at this time.
The search result transmission unit 122 uses the CPU 911 to acquire the data length 712 stored in the management table 212 by the management table management unit 147 from the data length 712c corresponding to the first record data 626c at this time. Data lengths 712c and 712d corresponding to the number of requests are read, and the transmission length 732 is calculated using the CPU 911 based on the read data lengths 712c and 712d.

The search result transmission unit 122 uses the communication device 915 to use the prefetch buffer 211 as a transmission buffer based on the calculated transmission position 731 and transmission length 732, and to transmit data having a transmission length 732 starting from the transmission position 731. The search result 620 is transmitted to the client device 300.
Using the CPU 911, the search result transmission unit 122 deletes the offsets 711c and 711d and the data lengths 712c and 712d corresponding to the transmitted record data 626c and 626d from the management table 212.
Similarly, when an empty area is created in the prefetch buffer 211 by transmission, the prefetch management unit 142 reads the record data 626 from the prefetch file 221 and the search result acquisition request reception unit 121 receives the search result acquisition request 520. The search result transmission unit 122 repeatedly transmits the search result 620 using the prefetch buffer 211 as a transmission buffer.

  In this way, the header storage area 721 is vacated in the prefetch buffer 211, and the search result transmission unit 122 writes the header data 623 in the header storage area 721 vacated in the prefetch buffer 211 at the time of transmission. Transmission can be performed using the buffer 211 as it is as a transmission buffer.

In this embodiment, the prefetch management unit 142 uses the storage device (RAM 914) as a header storage area 721 to store a storage area having a predetermined size (header length) from the beginning of the reserved storage area (prefetch buffer 211). The data (record data 626) converted by the data conversion unit 141 is stored in order from the storage area next to the header storage area 721.
The search result transmitting unit 122 uses the processing device (CPU 911) to generate header data 623 to be added to data to be transmitted to the client device 300, and uses the storage device (RAM 914) to manage the management table management. The generated header data 623 is stored in a storage area (header storage area 721) having a predetermined size (header length) before the storage area represented by the data (offset 711) stored by the unit 147, and the transmission device (communication) Using the device 915), the stored header data 623 and the data (record data 626) stored in the storage area subsequent to the storage area storing the header data 623 are transmitted to the client device 300. To do.

  According to the data search device 100 in this embodiment, the search result transmission unit 122 writes the header data 623 to the prefetch buffer 211, and uses the prefetch buffer 211 as a transmission buffer as it is, and the search result 620 is sent to the client device 300. Since the search result acquisition request receiving unit 121 receives the search result acquisition request 520 and the search result transmission unit 122 transmits the search result 620, the search result 620 can be transferred. There is an effect that the speed can be increased.

The prefetch management unit 142 in this embodiment uses the storage device (RAM 914) and uses one or more continuous storage areas for one piece of data (record data 626) converted by the data conversion unit 141. The data (record data 626) converted by the data conversion unit 141 is stored.
The management table management unit 147 further uses the storage device (RAM 914) to represent the number of storage areas (data length 712) in which the prefetch management unit 142 stores the respective data (record data 626). Is stored.
The search result transmission unit 122 uses the processing device (CPU 911) to perform the entire data to be transmitted to the client device 300 based on the number of areas (data length 712) represented by the data stored in the management table management unit 147. Data (transmission length 732) is calculated, and the data (search result) stored in the storage area is calculated based on the calculated length (transmission length 732) using the transmission device (communication device 915). 620) is transmitted to the client apparatus 300.

  According to the data search device 100 in this embodiment, the search result transmission unit 122 calculates the transmission length 732 based on the data length 712 stored in the management table 212 by the management table management unit 147, so the prefetch buffer 211 Can be used as a transmission buffer as it is.

  In the prefetch buffer 211 described above, the data search device 100 described above creates a space corresponding to the size of the header (header data 623) of the communication data at the head of the buffer, and packs the data portion (body, record data 626) of the communication data. Store.

  The data search apparatus 100 described above stores an offset 711 and a data length 712 each time one pre-read record is stored in the pre-read buffer 211 in the management table 212.

The data search system 800 (database system) described above includes a database server (data search apparatus 100) and a database client (client apparatus 300). The database server and the database client are connected via a network (Internet 940). It is connected. The database server (data search device 100) has a database (database storage unit 131), and the database (database storage unit 131) is accessed via a database management unit (database management device 102). A plurality of database clients (client devices 300) may be connected. Further, the database server and the database client may be a system composed of a plurality of devices, may be a single device, or may be a part of a single device.
The database client (client device 300) is a system that provides a client-side function when an application (application unit 301) accesses a database (database storage unit 131), and is connected to the database server (data search device 100). Then, a search request (search execution request 510) or the like is transmitted via the network (Internet 940), and an execution result (search status 610) or a search result 620 is received.
The database server (data search device 100) controls a reception unit (communication device 915) that receives a request from the database client (client device 300), a transmission unit (communication device 915) that transmits a result, and controls reception and transmission. The communication control unit (CPU 911) converts the search result acquired by the communication control unit through the database management unit (database management apparatus 102) into a communication data format (transmission format) by the communication data conversion unit (data conversion unit 141) and stores it. Prefetch buffer 211, management table 212 for storing each offset 711 and data length 712 of the prefetch buffer 211, prefetch file for storing data (record data 626) that cannot be stored in the prefetch buffer 211 on the memory (RAM 914) (Prefetch file 221), prefetch bar A file management unit (data conversion unit 141, prefetch management unit 142, management table management unit 147, search) which manages a file 211, a prefetch file (prefetch file 221), a management table 212, determines a communication buffer, and passes it to a transmission unit Result transmission unit 122).

  The application (application unit 301) searches the database, and acquires the search results by dividing the number of requests by the number of requests (the number of acquisition requests) into a plurality of times. The database management unit 132 of the database server (data search device 100) acquires the search results one by one from the database (database storage unit 131), but the transmission unit (search result transmission unit 122) has a plurality of search results ( Record data 626) can be transmitted. Further, from the database client (client device 300), a search execution request 510 specifying a query statement (search condition) indicating search open and a search result acquisition request 520 for acquiring search results for the specified number of times are closed. Is sent to the database server (data search apparatus 100).

When the search execution request 510 is transmitted from the database client (client device 300), the database server (data search device 100) operates as follows.
The receiving unit (search execution request receiving unit 111) receives the search execution request 510 from the database client (client device 300). The communication control unit (CPU 911) calls the buffer management unit (prefetch management unit 142, management table management unit 147), clears the prefetch buffer 211 and management table 212, and deletes the prefetch file (prefetch file 221) if there is one. Perform initialization processing. Next, the communication control unit (CPU 911) issues a search execution request to the database management unit 132. Since the end status is returned from the database management unit 132, the transmission unit (search result transmission unit 122) transmits the search execution result (search status 610) to the database client (client device 300). The database client (search status receiving unit 312) returns the result to the application (application unit 301), and the client side search execution request processing ends here.

  Subsequently, the database server (data search apparatus 100) executes a prefetch process for all search results. First, the communication control unit (CPU 911) issues a search result acquisition request to the database management unit (database management apparatus 102). The search result (record) returned from the database management unit 132 is passed to the buffer management unit (data conversion unit 141) by the communication control unit (CPU 911), and the communication data format (transmission) is transmitted by the communication data conversion unit (data conversion unit 141). Format).

  The communication data (search result 620) includes a fixed-length header (header data 623) and a variable-length body (record data 626). The header includes the body length. The body (record data 626) further includes a repetition of a fixed-length body header (field header 624) and variable-length data (field data 625). The body header includes a data type and a data length. The data conversion unit 141 creates body headers and data corresponding to the number of columns from one search result (record) read from the database to generate a body (record data 626), and the prefetch management unit 142 creates a prefetch buffer. 211 is stored. Since the character code and byte order of the search result depend on the operating system, the data conversion unit 141 performs conversion when creating the body (record data 626) if necessary. The body (record data 626) created from the search result is stored in the prefetch buffer 211 in the prefetch buffer 211, and the management table manager 147 sets the offset 711 and the data length 712 for each case in the management table 212. . When actually transmitting, the header portion (header data 623) of the communication data is required, so the first search result is arranged with a space of the size of the header. In the case other than the first case, the header (header data 623) can be overwritten by crushing the immediately preceding data, so there is no need to leave a gap. In addition, when the size of a search result column (field) is very large, the column data may be cut and set as body data with a length determined in advance or designated by an application (application unit 301). Good.

  The prefetch management unit 142 stores the record data 626 in the prefetch buffer 211 if the prefetch buffer 211 is empty, and in the prefetch file (prefetch file 221) if there is no free space. The destination is stored with the body packed. However, since the header portion (header data 623) of the communication data is required for the first record at the storage destination, the prefetch management unit 142 stores the record data 626 with a space for the header size. The management table management unit 147 stores the storage destination offset 711 and the data length 712 in the management table 212. When the final record of the search result is acquired from the database management unit 132, the communication control unit (CPU 911) issues a search end request to the database management unit 132, the database management unit 132 executes the search close, and the process ends. If the last record has not been acquired, the above processing is repeated.

When the search result acquisition request 520 is transmitted from the database client (client device 300), the database server (data search device 100) operates as follows.
The receiving unit (search result acquisition request receiving unit 121) receives the search result acquisition request 520 from the database client (client device 300). If all the search results for the search execution request 510 have been transmitted, the transmission unit (search result transmission unit 122) transmits that all the transmission results have been transmitted to the database client (client device 300), and the process ends. . If transmission of all the cases has not been completed, the communication control unit (CPU 911) calls the buffer management unit (search result transmission unit 122), and the search result transmission unit 122 reads the communication buffer (prefetch buffer 211) from the management table 212. Determine the offset. The determined offset becomes the communication buffer address. Subsequently, the search result transmission unit 122 obtains the body length of the communication data by adding the data length 712 corresponding to the number of requests from the management table 212, and overwrites the header (header data 623) in the communication buffer (prefetch buffer 211). To do. The transmission unit (search result transmission unit 122) transmits the contents of the communication buffer (prefetch buffer 211) to the database client (client device 300). The database client (search result receiving unit 322) passes the acquisition result (search result 620) to the application (application unit 301), and here, one search result acquisition request process on the client side ends.

Subsequently, the database server (data search apparatus 100) executes a prefetched content management process. First, the buffer management unit (prefetch management unit 142) checks the availability of the prefetch buffer 211 from the management table 212. If there is no free space in the prefetch buffer 211, the process ends. When there is a vacancy, the prefetch management unit 142 stores the content of the prefetch file (prefetch file 221) in the prefetch buffer 211. When all the contents of the prefetch file (prefetch file 221) can be stored in the prefetch buffer 211, the prefetch management unit 142 deletes the prefetch file (prefetch buffer 211) and ends the process.
Note that a plurality of buffers may be secured on a continuous memory in order to make it easy to control a group of prefetch buffers 211. In this case, the search results are stored in order from the first buffer, and the data of the prefetch file (prefetch file 221) is stored in the empty buffer that is transmitted to the database client (client device 300).

When the search end request 590 is transmitted from the database client (client device 300), the database server (data search device 100) operates as follows.
The receiving unit (search end request receiving unit 191) receives the search end request 590 from the database client (client device 300). The communication control unit (CPU 911) calls the buffer management unit (prefetch discard unit 193), releases the prefetch buffer 211 and the management table 212, and deletes the prefetch file (prefetch file 221) if any. The transmission unit (approval transmission unit 192) transmits the end status as a search end result (acceptance 690) to the database client (client device 300). The database client (acknowledgment reception unit 392) returns the result to the application (application unit 301), and all the search processing ends.

  As described above, all-read-ahead processing for a search request (search execution request 510) from a client (client device 300) is performed using the pre-read buffer 211 in which data is arranged so that it can also be used as a communication buffer. In a database system that has a variable length and a very large data type, and consumes a large amount of server resources from opening to closing of the database as a result of searching, it can quickly release resources for searching the database server, Hardware resources can be used effectively. In addition, since it is not necessary to convert the prefetch buffer 211 to the communication data format every time the search result is transmitted, the transfer performance of the search result can be maintained.

Embodiment 4 FIG.
The fourth embodiment will be described with reference to FIGS.

FIG. 13 is a block configuration diagram showing an example of the functional block configuration of each device constituting the data search system 800 in this embodiment.
Note that portions common to the data search system 800 described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted here.

The client device 300 further includes a specification acquisition request transmission unit 351 and a specification reception unit 352.
The specification acquisition request transmission unit 351 transmits a specification acquisition request 550 to the data search device 100 using the communication device 915. The detail acquisition request 550 is data requesting to acquire one record from the database stored in the database storage unit 131, and includes data representing instruction information indicating the record to be acquired.
The specification receiving unit 352 uses the communication device 915 to receive the specification 650 transmitted by the data search device 100. The detail 650 includes data of a record pointed to by the instruction information included in the detail acquisition request.

  The server device 101 further includes a detail acquisition request receiving unit 151, a detail transmitting unit 152, a detail converting unit 161, and a detail managing unit 162.

  The specification acquisition request receiving unit 151 receives the specification acquisition request 550 transmitted by the client device 300 using the communication device 915. Using the CPU 911, the detail acquisition request receiving unit 151 outputs instruction information represented by data included in the received detail acquisition request 550.

  The database management unit 132 uses the CPU 911 to input the instruction information output from the detail acquisition request reception unit 151. The database management unit 132 uses the CPU 911 to open a database including a record pointed to by the instruction information among the databases stored in the database storage unit 131 based on the input instruction information. The database management unit 132 uses the CPU 911 to acquire one record pointed to by the instruction information from the opened database. The database management unit 132 uses the CPU 911 to output one acquired record. The database management unit 132 uses the CPU 911 to close the opened database.

  The detail conversion unit 161 uses the CPU 911 to input one record output from the database management unit 132. Similar to the data conversion unit 141, the detail conversion unit 161 uses the CPU 911 to convert one input record into a format to be transmitted to the client device 300. Using the CPU 911, the detail conversion unit 161 outputs the converted transmission format data (hereinafter referred to as “detailed data”).

The detail management unit 162 uses the CPU 911 to input the detail data output by the detail conversion unit 161. The detail management unit 162 uses the RAM 914 to reserve a storage area for storing the detail data (hereinafter referred to as “detail buffer 213”) in advance. The detail management unit 162 uses the RAM 914 to store the entered detail data in the detail buffer 213.
The specification transmission unit 152 transmits the specification data stored in the specification buffer 213 by the specification management unit 162 as the specification 650 to the client device 300 using the communication device 915.

  If the data contained in one record of the database is large, when attempting to acquire all the data contained in the retrieved record at the time of data retrieval, the amount of data transmitted from the data retrieval apparatus 100 to the client apparatus 300 becomes enormous. Therefore, as a search result, only the data representing the record is acquired, and based on the acquired data, the record for which more detailed data is desired is narrowed down, and detailed data is acquired for the narrowed down record. There are cases where the following steps are taken.

  FIG. 14 is a diagram showing an example of a display screen displayed by the client device 300 using the display device 901 in the log management system using the data search system 800 in this embodiment.

The search condition input screen 850 is a screen for inputting search conditions, and includes a search condition input field 851 and a search button 852.
When the user inputs a search condition in the search condition input field 851 and presses the search button 852, the data search system 800 executes a search. The client device 300 generates a search result screen 860 and displays it using the display device 901.

The search result screen 860 is a screen for displaying the search result, and includes a search result display field 861, a full text display button 862, a next screen button 863, and a condition change button 864.
The search result display field 861 is an area for displaying a summary of searched records in one line and displaying a summary of a plurality of records at a time.
When the user selects any of the records displayed in the search result display field 861 and presses the full text display button 862, the client device 300 generates a full text display screen 870 and displays it using the display device 901. To do.
When the user presses the next screen button 863, the client device 300 generates a search result screen 860 that displays a summary of the next plurality of records that could not be displayed at once, and uses the display device 901. indicate.
When the user presses the condition change button 864, the client apparatus 300 generates a search condition input screen 850 and displays it using the display apparatus 901.

The full text display screen 870 is a screen for displaying detailed search results, and includes a date / time display column 871, a log display column 872, and a return button 873.
The date display column 871 is an area for displaying the date and time when the log was recorded.
The log display column 872 is an area for displaying the contents of the log.
When the user presses the return button 873, the client device 300 displays the original search result screen 860 using the display device 901.

  FIG. 15 is a flowchart showing an example of the flow of log management processing in which the client device 300 in this embodiment realizes the log management system described above.

In the search condition input screen display step S461, the client device 300 (search condition input screen generation unit) uses the CPU 911 to generate the search condition input screen 850. The client device 300 (search condition input screen display unit) displays the generated search condition input screen 850 using the display device 901.
In the search button determination step S462, the client device 300 (search button determination unit) uses the CPU 911 to determine whether or not the search button 852 has been pressed. If it is determined that the search button 852 has been pressed, the process proceeds to the search execution request transmission step S471. If it is determined that the search button 852 is not pressed, the search button determination step S462 is repeated.

  In the search execution request transmission step S471, the client device 300 (search execution request generation unit) is input to the search condition input field 851 of the search condition input screen 850 displayed in the search condition input screen display step S461 using the CPU 911. A search execution request 510 is generated based on the search condition. Further, the search execution request 510 generated by the client device 300 includes data specifying data to be transmitted as the search result 620 among the searched records. In this example, the client device 300 generates a search execution request 510 including data specifying three fields of record number, date / time, and body (however, only a predetermined number of characters from the top) as data to be transmitted. The search execution request transmission unit 311 transmits the generated search execution request 510 to the data search device 100 using the communication device 915.

In the search status reception step S472, the search status reception unit 312 receives the search status 610 transmitted by the data search device 100 using the communication device 915.
In the search success / failure determination step S473, the client device 300 (search success / failure determination unit) determines whether the search has succeeded or failed based on the search status 610 received by the search status reception unit 312 in the search status reception step S472. . When it is determined that the search is successful, the process proceeds to the search result acquisition request transmission step S481. If it is determined that the search has failed, the process returns to the search condition input screen display step S461.

  In the search result acquisition request transmission step S <b> 481, the client device 300 (search result acquisition request generation unit) generates a search result acquisition request 520 using the CPU 911. In this example, the client device 300 generates a search result acquisition request 520 using the number of rows that can be displayed in the search result display field 861 as the number of acquisition requests. The search result acquisition request transmission unit 321 uses the communication device 915 to transmit the generated search result acquisition request 520 to the data search device 100.

In the search result receiving step S <b> 482, the search result receiving unit 322 receives the search result 620 transmitted by the data search device 100 using the communication device 915.
In the search result screen display step S483, the client device 300 (search result screen generation unit) uses the CPU 911 to search the search result screen 860 based on the search result 620 received by the search result reception unit 322 in the search result reception step S482. Is generated. Using the display device 901, the client device 300 (search result screen display unit) displays the generated search result screen 860.
In the button determination step S <b> 484, the client device 300 (button determination unit) uses the CPU 911 to determine which of the full text display button 862, the next screen button 863, and the condition change button 864 has been pressed. If it is determined that the full-text display button 862 has been pressed, the process proceeds to the detailed acquisition request transmission step S491. If it is determined that the next screen button 863 has been pressed, the process returns to the search result acquisition request transmission step S481. If it is determined that the condition change button 864 has been pressed, the process returns to the search condition input screen display step S461.

  In the detail acquisition request transmission step S491, the client device 300 (detail acquisition request generation unit) uses the CPU 911 to generate a detail acquisition request 550. In this example, the client device 300 obtains the record number of the selected record based on the record selected from the search result display field 861 of the search result screen 860 displayed in the search result screen display step S483, and the obtained record A detail acquisition request 550 is generated using the number as instruction information. The detail acquisition request transmission unit 351 transmits the generated detail acquisition request 550 to the data search device 100 using the communication device 915.

In the specification receiving step S492, the specification receiving unit 352 receives the specification 650 transmitted by the data search device 100 using the communication device 915.
In the full text display screen display step S493, the client device 300 (full text display screen generation unit) uses the CPU 911 to generate the full text display screen 870 based on the specification 650 received by the specification reception unit 352 in the specification reception step S492. . The client device 300 (full-text display screen display unit) displays the generated full-text display screen 870 using the display device 901.
In the return button determination step S494, the client device 300 (return button determination unit) uses the CPU 911 to determine whether or not the return button 873 has been pressed. If it is determined that the return button 873 has been pressed, the process returns to the search result screen display step S483. When it is determined that the return button 873 has not been pressed, the return button determination step S494 is repeated.

  In response to the operation of the client device 300 as described above, the data search device 100 operates as follows.

When the search execution request transmission unit 311 transmits the search execution request 510 in the search execution request transmission step S471, in the data search device 100, the search execution request reception unit 111 receives the search execution request 510, and the database management unit 132 stores the database. Search for. The database management unit 132 acquires the retrieved record from the database, and the prefetch management unit 142 stores the record data 626 in the prefetch buffer 211 (or the prefetch file 221).
Thereafter, when the search result acquisition request transmission unit 321 transmits the search result acquisition request 520 in the search result acquisition request transmission step S481, in the data search device 100, the search result acquisition request reception unit 121 receives the search result acquisition request 520, The search result transmission unit 122 transmits the search result 620 using the prefetch buffer 211 as a transmission buffer.
Each time the user presses the next screen button 863, the above operation is repeated, and the client apparatus 300 can acquire the search results 620 for all the searched records.

Before the client device 300 acquires the search results 620 for all the searched records, the user presses the condition change button 864 to return to the search condition input screen 850, and enter a new search condition to search. Assume that the button 852 is pressed. The client device 300 generates a search execution request 510 including search condition data 512 representing a new search condition, and the search execution request transmission unit 311 transmits the search execution request 510 in a search execution request transmission step S471.
In the data search apparatus 100, the search execution request receiving unit 111 receives a new search execution request 510, and the database management unit 132 searches the database. The database management unit 132 acquires the retrieved record from the database, and the prefetch management unit 142 stores the record data 626 in the prefetch buffer 211 (or the prefetch file 221). At this time, old search results stored in the prefetch buffer 211 (or prefetch file 221) are overwritten and discarded.
Therefore, even if the client apparatus 300 does not transmit the search end request 590, the search result that has not been acquired until the end does not remain in the server apparatus 101, and the resources of the server apparatus 101 are not wasted.

It is assumed that the user presses the full text display button 862 before the client device 300 acquires the search results 620 for all the searched records. In the client apparatus 300, the detail acquisition request transmission unit 351 transmits the detail acquisition request 550 in the detail acquisition request transmission step S491.
In the data search device 100, the detail acquisition request receiving unit 151 receives the detail acquisition request 550, and the database management unit 132 searches the database to acquire the record indicated by the instruction information. The detail management unit 162 stores the detail data in the detail buffer 213, and the detail transmission unit 152 transmits the detail 650 using the detail buffer 213 as a transmission buffer.
At this time, the contents of the prefetch buffer 211 (or the prefetch file 221) are kept as before. Therefore, when the user presses the return button 873 to return to the search result screen 860 and presses the next screen button 863 to view the continuation, the data search device 100 transmits the search result 620 of the previous continuation.

In this example, the instruction information represented by the data included in the detail acquisition request 550 indicates a record with “how many record numbers”. From another point of view, the instruction information can be regarded as a search condition for searching for a record having “what number is the record number”. Therefore, the client device 300 does not transmit the detail acquisition request 550 to the data search device 100 but transmits a search execution request 510 including the search condition data 512 representing the search condition to the data search device 100. But you can get the data of the specified record.
However, when the client apparatus 300 transmits the search execution request 510 instead of the detail acquisition request 550, the data search apparatus 100 discards the old search result, so when the user returns to the search result screen 860 and tries to continue, It will be necessary to search the database again.
On the other hand, when the client device 300 transmits the detail acquisition request 550, the detail transmission unit 152 transmits the details 650 using the detail buffer 213 as a transmission buffer. Therefore, the old search result is held in the prefetch buffer 211, and even when the user returns to the search result screen 860 and tries to continue, it is not necessary to search the database again.

The data search device 100 in this embodiment further includes a specification acquisition request receiving unit 151, a specification conversion unit 161, a specification management unit 162, and a specification transmission unit 152.
The detail acquisition request receiving unit 151 uses the reception device (communication device 915) to receive a detail acquisition request 550 including data representing instruction information indicating data (record) acquired from the database from the client device 300. It is characterized by doing.
The database management unit 132 uses the processing device (CPU 911) to store the database storage unit 131 based on instruction information represented by data included in the detail acquisition request 550 received by the detail acquisition request reception unit 151. The data (record) indicated by the instruction information is obtained from the database.
The detail conversion unit 161 uses the processing device (CPU 911) to convert the data acquired by the database management unit 132 into a format to be transmitted to the client device 300.
The detail management unit 162 stores the data (detailed data) converted by the detail conversion unit 161 (in the detail buffer 213) using the storage device (RAM 914).
The detail transmission unit 152 transmits the data (detail data) stored by the detail management unit 162 (in the detail buffer 213) to the client device 300 using the transmission device (communication device 915). To do.

  According to the data search device 100 in this embodiment, the detail management unit 162 stores data (detailed data) in a storage area (detail buffer 213) different from the storage area (prefetch buffer 211) secured by the prefetch management part 142. Since the detail transmission unit 152 transmits the data stored in the detail management unit 162, the data (record data 626) stored in the prefetch management unit 142 is held as it is. As a result, it is possible to interrupt another search in the middle of a certain search while holding the search result.

  The data search method described above uses a detail buffer (detail buffer 213) for transmitting only one search result, in addition to the prefetch buffer 211 for transmitting a plurality of search results collectively.

  The data search apparatus 100 described above includes a detail buffer (detail buffer 213) for transmitting only one search result, in addition to the prefetch buffer 211 for transmitting a plurality of search results collectively. The detail buffer (detail buffer 213) is not managed by the buffer management unit (prefetch management unit 142).

  The application (application unit 301) searches the database and acquires one search result. For example, this is the case where a table with a sequential number assigned to each row is searched by that number. From the database client (client device 300), a detail record acquisition request (detail acquisition request 550) for acquiring all data of the specified record is transmitted to the database server (data search device 100).

When the database client (client device 300) transmits a detail record acquisition request (detail acquisition request 550), the database server (data search device 100) operates as follows.
The receiving unit (detail acquisition request receiving unit 151) receives the detail record acquisition request (detail acquisition request 550) from the database client (client device 300). The communication control unit (CPU 911) creates an inquiry statement for specifying a record designated from the database client (client device 300) to the database management unit 132, and makes a search execution request. Since the end status is returned from the database management unit 132, the communication control unit (CPU 911) subsequently requests the database management unit 132 to obtain a search result. The communication control unit (CPU 911) passes the search result returned from the database management unit 132 to the communication data conversion unit (detail conversion unit 161). After the communication data conversion unit (detail conversion unit 161) converts to the communication data format, the detail management unit 162 secures and stores the detail buffer (detail buffer 213). The transmission unit (detail transmission unit 152) transmits the contents of the detail buffer (detail buffer 213) to the database client (client device 300), releases the detail buffer (detail buffer 213), and ends the processing.
Note that in order to acquire a plurality of search results from the database client (client device 300) as a free query, the database server (data) when a search execution request 510, a search result acquisition request 520, and a search end request 590 are transmitted. The operation of the search device 100) is the same as that described in the first to third embodiments.

For example, when an application (application unit 301) makes a search execution request, the number of search results to be acquired (the number of acquisition requests) is one screen, and the search results include very large data. Specifies the length of the result column. The client device 300 displays a list of the results acquired by the search result acquisition request 520 as they are. The user (user) gives an instruction when there is a result that the user wants to see the entire list, and the application executes a detailed record acquisition request. The user gives an instruction to display the next list screen, and the application executes the next search result acquisition request.
As a result, all the search results are acquired by the application, and it is not necessary to control the data display, and it is possible to acquire only the necessary amount. Therefore, in a database in which a data type having a very large size exists, the size of the search result also becomes very large. There is no pressure.

  As described above, a buffer for one detail record is provided separately from the prefetch buffer 211, and a search execution request 510, a search result acquisition request 520, and a search end, which are a general series of search processing for the database. Since another search can be interrupted during the request 590, the application need not hold a search result of a very large amount of data unnecessarily.

1 is a system configuration diagram illustrating an example of an overall configuration of a data search system 800 according to Embodiment 1. FIG. FIG. 3 is a sequence diagram illustrating an example of a data flow in the data search system 800 according to the first embodiment. 3 is a diagram showing an example of the appearance of a server device 101, a database management device 102, a database storage device 103, and a client device 300 in Embodiment 1. FIG. 2 is a diagram illustrating an example of hardware resources of a server device 101, a database management device 102, a database storage device 103, and a client device 300 according to Embodiment 1. FIG. FIG. 3 is a block configuration diagram illustrating an example of a functional block configuration of each device that configures the data search system 800 according to the first embodiment. FIG. 3 is a diagram illustrating an example of a data format of data transmitted and received between the client device 300 and the data search device 100 according to the first embodiment. The flowchart figure which shows an example of the flow of the search process in which the data search device 100 in Embodiment 1 searches a database, and the result transmission process in which the data search device 100 transmits a search result. FIG. 6 schematically illustrates operations of a data conversion unit 141, a prefetch management unit 142, and a search result transmission unit 122 in the first embodiment. The figure which shows an example of data structures, such as the structure of the detailed block of the prefetch management part 142 in Embodiment 2, and the prefetch buffer 211. FIG. The flowchart figure which shows an example of the flow of the search process in which the data search device 100 in Embodiment 2 searches a database, and the result transmission process in which the data search device 100 transmits a search result. The flowchart figure which shows an example of the flow of search result transmission process S432 in which the search result transmission part 122 in Embodiment 3 transmits the search result 620. FIG. 14 is a diagram illustrating an example of a data structure of the prefetch buffer 211 and the like in the third embodiment. FIG. 9 is a block configuration diagram illustrating an example of a functional block configuration of each device that configures a data search system 800 according to a fourth embodiment. FIG. 20 is a diagram showing an example of a display screen displayed by the client device 300 using the display device 901 in the log management system using the data search system 800 in the fourth embodiment. The flowchart figure which shows an example of the flow of the log management process which the client apparatus 300 in Embodiment 4 implement | achieves the log management system mentioned above.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Data search apparatus, 101 Server apparatus, 102 Database management apparatus, 103 Database storage apparatus, 111 Search execution request reception part, 112 Search status transmission part, 121 Search result acquisition request reception part, 122 Search result transmission part, 131 Database storage part , 132 Database management unit, 141 Data conversion unit, 142 Prefetch management unit, 143 Prefetch buffer management unit, 144 Prefetch file management unit, 147 Management table management unit, 151 Detail acquisition request reception unit, 152 Detail transmission unit, 161 Detail conversion unit 162 Detail management unit, 213 Detail buffer, 191 Search end request receiving unit, 192 Acknowledgment transmission unit, 193 Prefetch discard unit, 211 Prefetch buffer, 212 Management table, 221 Prefetch file, 300 Client device, 3 DESCRIPTION OF SYMBOLS 1 Application part, 302 Interface part, 311 Search execution request transmission part, 312 Search status reception part, 321 Search result acquisition request transmission part, 322 Search result reception part, 351 Detailed acquisition request transmission part, 352 Detailed reception part, 391 Search end Request transmission unit, 392 Acknowledgment reception unit, 501 Code unit, 502 Data unit, 510 Search execution request, 511 Search execution request code, 512 Search condition data, 520 Search result acquisition request, 521 Search result acquisition request code, 522 Number of acquisition requests Data, 550 Detail acquisition request, 590 Search end request, 591 Search end request code, 610 Search status, 611 Search status code, 612 Search status data, 620 Search result, 621 Search result code, 622 Data header, 623 Header data, 624 field header, 625 field data, 626 record data, 650 specification, 690 OK, 691 OK code, 711 offset, 712 data length, 721 header storage area, 722-724 free area, 731 transmission position, 732 transmission length 800 data search system, 850 search condition input screen, 851 search condition input field, 852 search button, 860 search result screen, 861 search result display field, 862 full text display button, 863 next screen button, 864 condition change button, 870 Full text display screen, 871 Date / time display column, 872 Log display column, 873 Return button, 901 Display device, 902 Keyboard, 903 Mouse, 904 FDD, 905 CDD, 906 Printer device, 907 Scanner device, 910 system unit, 911 CPU, 912 bus, 913 ROM, 914 RAM, 915 communication device, 920 magnetic disk device, 921 OS, 922 window system, 923 program group, 924 file group, 931 telephone, 932 facsimile machine, 940 Internet 941 Gateway, 942 LAN.

Claims (9)

In a data retrieval device that retrieves a database in response to a request from a client device,
Storage device for storing data, processing device for processing data, transmitting device for transmitting data, receiving device for receiving data, database storage unit, search execution request receiving unit, database management unit, data A conversion unit, a prefetch management unit, a search result acquisition request reception unit, and a search result transmission unit;
The database storage unit stores the database using the storage device,
The search execution request receiving unit receives a search execution request including data representing a search condition for searching the database from the client device using the receiving device,
The database management unit uses the processing device to change from the database stored in the database storage unit to the search condition based on the search condition represented by the data included in the search execution request received by the search execution request receiving unit. Search for matching data, and use the processing device to obtain the searched data from the database stored in the database storage unit,
The data conversion unit converts the data acquired by the database management unit into a format to be transmitted to the client device using the processing device,
The prefetch management unit stores the data converted by the data conversion unit using the storage device,
The search result acquisition request receiving unit receives, from the client device, a search result acquisition request including data representing the number of acquisition requests for data that the client device requests to acquire using the receiving device,
From the data stored in the prefetch management unit based on the number of acquisition requests represented by the data included in the search result acquisition request received by the search result acquisition request reception unit using the transmission device. A data search device that transmits data of the number of acquisition requests to the client device. The data search apparatus further includes a management table management unit,
The prefetch management unit secures a plurality of ordered storage areas using the storage device, stores the data converted by the data conversion unit using the storage device in the secured storage area,
The management table management unit uses the storage device to store data representing a storage area in which the prefetch management unit stores data,
The search result transmission unit transmits data stored in a storage area represented by data stored in the management table management unit to the client device using the transmission device. Data retrieval device. The prefetch management unit uses the storage device as a storage area of a predetermined size from the beginning of the secured storage area as a header storage area, and converts the data converted by the data conversion unit to the next of the header storage area. Store in order from the storage area,
The search result transmission unit generates header data to be added to data to be transmitted to the client device using the processing device, and uses the storage device to store a storage area represented by the data stored by the management table management unit The generated header data is stored in a storage area of a predetermined size before, and the stored header data and the data stored in the storage area subsequent to the storage area storing the header data using the transmission device are stored. The data search device according to claim 2, wherein the data is transmitted to the client device. The prefetch management unit uses the storage device to store data converted by the data conversion unit using one or more continuous storage areas for each piece of data converted by the data conversion unit,
The management table management unit further stores data representing the size of the storage area in which the prefetch management unit stores the respective data using the storage device,
The search result transmission unit calculates the length of the entire data to be transmitted to the client device based on the size represented by the data stored in the management table management unit, using the processing device, The data search device according to claim 3, wherein the data search device transmits the data stored in the storage area to the client device based on the calculated length. The data search apparatus further includes a detail acquisition request receiving unit, a detail converting unit, a detail managing unit, and a detail transmitting unit.
The specification acquisition request receiving unit receives, from the client device, a specification acquisition request including data representing instruction information indicating data acquired from the database, using the receiving device.
The database management unit further uses the processing device to execute the instruction from the database stored in the database storage unit based on instruction information represented by data included in the detail acquisition request received by the detail acquisition request receiving unit. Get the data pointed to by the information,
The detail conversion unit uses the processing device to convert the data indicated by the instruction information acquired by the database management unit into a format to be transmitted to the client device,
The detail management unit stores the data converted by the detail conversion unit using the storage device,
5. The data search device according to claim 1, wherein the specification transmission unit transmits the data stored in the specification management unit to the client device using the transmission device. 6. The data search device has two or more storage devices,
Of the storage devices, the second storage device takes a longer time to write and read data than the first storage device of the storage devices,
The prefetch management unit includes a prefetch buffer management unit and a prefetch file management unit,
The prefetch buffer management unit secures a storage area for storing data using the first storage device, determines whether there is a free space in the secured storage area using the processing device, and secures it. When it is determined that there is an empty storage area, the data converted by the data conversion unit is stored in the empty storage area using the first storage device, and there is no empty storage area. If determined, the second storage device is used to store the data converted by the data converter,
The prefetch file management unit determines whether there is data stored by the prefetch buffer management unit using the second storage device using the processing device, and the prefetch buffer management unit uses the second prefetch buffer management unit. When it is determined that there is data stored using the storage device, it is determined whether there is an empty storage area secured by the prefetch buffer management unit, and the storage area secured by the prefetch buffer management unit is free If it is determined that there is, using the first storage device, the prefetch buffer management unit stores the data stored using the second storage device in a free storage area,
The search result transmission unit transmits data stored by the prefetch management unit using the first storage device to the client device using the transmission device. The data search device according to any one of the above. A client device and the data search device according to any one of claims 1 to 6,
The client device includes a transmission device that transmits data, a reception device that receives data, a search execution request transmission unit, a search result acquisition request transmission unit, and a search result reception unit,
The search execution request transmission unit transmits the search execution request to the data search device using the transmission device,
The search result acquisition request transmission unit transmits the search result acquisition request to the data search device using the transmission device,
The search result receiving unit receives the data transmitted by the search result transmitting unit using the receiving device.   A program that causes a computer to function as the data search device according to any one of claims 1 to 6. Data search in which a data search device having a storage device for storing data, a processing device for processing data, a transmission device for transmitting data, and a reception device for receiving data searches a database in response to a request from a client device In the method
The receiving device receives a search execution request including data representing a search condition for searching the database from the client device;
The processing device searches the database for data that matches the search condition based on the search condition represented by the data included in the received search execution request,
The processing device acquires the retrieved data from the database,
The processing device converts the acquired data into a format to be transmitted to the client device,

The storage device stores the converted data,
The receiving device receives a search result acquisition request including data representing the number of acquisition requests for data that the client device requests to acquire from the client device,
A data search method characterized in that the transmission device transmits data of the number of acquisition requests from the stored data to the client device based on the number of acquisition requests represented by data included in the received search result acquisition request. .

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