JPH043235A - Data base system - Google Patents

Abstract

PURPOSE:To decrease the decision processing, and also, to curtail the memory quantity by transferring the data to a host variable area by using a host variable description list obtained by analyzing a host variable and a relation of a physical position of a record. CONSTITUTION:A relation of a physical position of a host variable in a data base access request described in a user application program means 10 and a record stored on a data base 30 of a secondary storage device 3 is analyzed 20 and outputted as a host variable description list 11. By using the host variable description list 11 outputted by this processing, at the time of execution of the user application program means 10, data is transferred 13 to a host variable area on the user application program means 10 from the data base 30 of the secondary storage device 3. In such a way, by curtailing the processing for specifying an object line, the data transfer can be executed at a high speed, and also, an increase of the memory quantity can be suppressed.

Description

[Detailed Description of the Invention] C. Industrial Application Field] The present invention is used for data transfer control in a database system. The present invention is a data transfer method for a database system in which the smallest unit of data is managed as a column, and a user searches a table containing these columns under arbitrary conditions to read out a set of columns. In a database system that provides a table of columns collected by concatenating the minimum unit columns to the user, and allows the user to search using arbitrary conditions and read out an arbitrary set of columns, host variables and By transferring data from the database to the host variable area on the user application program using the host variable description list obtained by analyzing the relationship between the physical locations of records stored on the secondary storage device. , which enables high-speed data transfer without scanning unnecessary column information when reading data.

[Conventional technology]

Conventionally, the smallest unit of data is managed as a column, and the storage structure is such that multiple columns are concatenated and stored as a record in a secondary storage device, and a collection of concatenated columns is provided to the user as a table. The data transfer method of a database system that reads a set of arbitrary columns by searching with arbitrary conditions is to retrieve the records and host variables on the secondary storage device of the columns requested to be transferred when the user application program means is executed. embedding information on the user application program means in which the records on the secondary storage device of the table relating to all database access requests in the user application program means are associated with the arrangement relationships of the host variables; Data was transferred by comparing the column requested to be transferred with the above information during execution.

[Problem to be solved by the invention]

In the above-mentioned conventional technology, in order to read a set of arbitrary columns of a user, a process is performed to measure the arrangement relationship between the columns and the secondary storage device when the user application program means is executed, and the column is taken as the minimum unit. A lot of processing is required to specify the target column in the transfer of an arbitrary column requested by the user application program from the record structure,
Furthermore, there is a drawback that the amount of memory required increases due to the expansion of placement correspondence information other than the target column.

The present invention aims to eliminate such drawbacks, and aims to provide a system that can reduce the number of determination processes and the amount of memory.

[Means to solve the problem]

The present invention comprises a secondary storage device including a database, a data processing means for processing data, and a control means including a user application program means and a data transfer means. means for managing the plurality of columns as a concatenated record in the database; and providing the user with a collection of concatenated columns as a table, and allowing the user application program means to store the concatenated columns as a record in the database; and means for performing a search and reading out a set of arbitrary columns into an area on the user application program means, wherein the control means receives host variables from among the database access requests written in the user application program means. and access information analysis means for analyzing the relationship between the physical positions of records stored on the database and outputting the result as a host variable description list.

The data transfer means uses the host variable description list outputted by the processing of the access information analysis means to transfer data from the database to the host variable area on the user application program means when the user application program means is executed. It is desirable to include means for transmitting the information to the

[Effect]

The relationship between the host variable and the physical position of the record stored in the database of the secondary storage device is analyzed in the database access request written in the user application program means and output as a host variable description list.

Using the host variable description list outputted in this process, data is transferred from the database of the secondary storage device to the host variable area on the user application program means when the user application program means is executed.

Thereby, data transfer can be performed at high speed by reducing the processing for specifying the target column, and furthermore, it is possible to suppress an increase in the amount of memory.

〔Example〕

Next, the embodiments of the present invention will be described as SQL (Structure
ed Query Language + Structured Matching Language)
Let's take an example of database access using . FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

The embodiment of the present invention comprises a secondary storage device 3 including a database 30, a data processing means 2 for processing data, a control means 1 including a user application program means 1G and a data transfer means 13. 1, a means for managing the minimum unit of data as a column and storing the plurality of columns as a concatenated record in the database 30;
A collection of connected columns is provided to the user 4 as a table, and the user application program means 10 searches the table under arbitrary conditions and reads out a set of arbitrary columns into an area on the user application program means 10. The control means 1 further includes a host variable description list 11 that analyzes the relationship between host variables and physical positions of records stored on the database 30 in the database access request written in the user application program means 10. The access information analysis means 12 outputs the access information as follows. Further, the data transfer means 13 uses the host variable description list 11 outputted by the processing of the access information analysis means 12 to
means for transferring data from the database 30 to a host variable area on the user application program means 10 during execution of the program.

The user application program means 10 includes SQL
Database access is described in language, and the host variable storage list 11 describes the positional relationship between host variables obtained by analyzing access information and records on the secondary storage device 3.

The access information analysis means 12 analyzes the database access described in the SQL request and outputs the host variable description list 11, and the data transfer means 13 uses the host variable description list 11 to transfer data to the host variable area. .

In the database 30 of the secondary storage device 3, the minimum unit of data is managed as a column and stored as a record in which a plurality of columns are connected.

The user application program means 10 executes a user processing procedure 2 for performing user-specific processing as shown in FIG.
1 and SQL command 2 that accesses multiple databases.
2.23.24 and host variables 25.26.27 from which data is read by database access.

The SQL command 22 searches the table 41 for the column 43 whose value is "A". SQL instruction 23 reads data from the set retrieved by SQL instruction 22 into host variable 25.26 in columns 42 and 44. SQL command 24 is SQL command 2
Data from the set searched by 2 is stored in the host variable 25.
．． 27 reads columns 42.44.

The host variable description list 11 is created for each SQL command that reads data into the host variable area as shown in FIGS. Listings 31 and 32 are output.

The host variable description list 31 holds a pointer to the host variable 25 and its physical position in the record in column 42 in entry 3]1, and holds a pointer to the host variable 26 and its physical position in the record in column 44 in entry 312. Hold.

The host variable description list 32 holds a pointer to the host variable 25 and its physical position in the record in column 42 in an entry 321, and holds a pointer to the host variable 27 and its physical position in the record in column 44 in end 1J322. .

The database 30 is in the form of a table 41, as shown in FIG. 4, and the table 41 is composed of columns 42, 43, and 44.

The access information analysis means 12 extracts the SQL command in a process 51 as shown in FIG. If there is no instruction to extract, the process ends. If there is an instruction to take out, process 52
Move to. In process 52, the SQL command is determined and “DECLAR
If it is an "E'" command, the process moves to process 53, and if it is a "FETCH" command, the process moves to process 54.

In process 53, the physical position within the record of the column used in the instruction is calculated and stored, and the process returns to process 51. In process 54, the host variable description list 11 is output from the position in the record stored in process 53 and the host variable used in the instruction, and the process returns to process 51.

The data transfer means 13 takes out an entry from the host variable description list 11 input in process 61 as shown in FIG. If there is no instruction to extract, the process ends. If there is an instruction to take out, the process moves to step 62. In process 62, data is transferred using the physical position of the IJO column retrieved in process 61 and the host variable pointer, and process 61
Return to

〔Effect of the invention〕

As described above, according to the present invention, data can be transferred at high speed without scanning information in unnecessary columns (columns that are not read) when reading data.

In other words, assuming that a table in a database is composed of n columns and m columns are to be read, the conventional technology requires 9 times to determine whether or not to transfer to the host variable area. According to the method, the number of determination processes is m (n>m), and it is possible to reduce the number of determination processes (n−m).

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the user application program means according to the embodiment of the present invention. FIGS. 3(a) and 3(b) are diagrams showing the structure of a host variable description list according to an embodiment of the present invention. FIG. 4 is a diagram showing the configuration of a database according to an embodiment of the present invention. FIG. 5 is a flowchart showing the processing flow of the access information analysis means according to the embodiment of the present invention. FIG. 6 is a flowchart showing the processing flow of the data transfer means according to the embodiment of the present invention. 1... Control means, 2... Data processing means, 3...
Secondary storage device, 4... User, 10... User application program means, 11.31.32...
Host variable description list, 12... Access information analysis means, 13... Data transfer means, 30... Database. Patent Applicant: NEC Corporation, -7゜Representative: Patent Attorney Nao Takashi Ide: M 1 Design Sales Example 111 Liquor Ebrigution Handyaku 6 Trees Surprise Figures! + 77 [Processing process for discontinuation of base information analysis +6) +1)) Power example Host 粱计数ritary strike Takumi Tsukuzume Fumihiko series Data base/l lecture Part 4 Obstacle fence 1 After data transfer + Death processing chart

Claims (1)

[Claims] 1. A secondary storage device including a database, a data processing means for processing data, and a control means including a user application program means and a data transfer means; means for managing the minimum unit as a column and storing the plurality of columns as a concatenated record in the database; and providing the user with a collection of concatenated columns as a table, and the user application program means for storing the concatenated columns in the database. and means for performing a search under arbitrary conditions and reading out a set of arbitrary columns into an area on the user application program means, wherein the control means receives a database access request written in the user application program means. A database system comprising access information analysis means for analyzing the relationship between host variables and physical positions of records stored on the database and outputting the result as a host variable description list. 2. The data transfer means uses the host variable description list outputted by the processing of the access information analysis means to transfer data from the database to the host variables on the user application program means when the user application program means is executed. 2. A database system according to claim 1, further comprising means for transferring data to a region.