JP3386537B2 - Database system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database system, and more particularly to a database system which enables efficient reference of data when a terminal device requests list data from the database device.

[0002]

2. Description of the Related Art Generally, a database system includes a database device (also called a server) for storing data,
It is composed of a terminal device (also called a client) communicatively connected to the database device.

In this database system, the terminal device is a remote terminal of the database device, but when the terminal device refers to the data in the database device, FIG.
The method by "active operation of terminal device" shown in FIG.
There is a method by "passive operation of terminal device" shown in (b).

The active operation of the terminal device is, as shown in FIG. 8A, a list data is sent from the database device when the terminal device requests data. The list data in this case is all data including unupdated data that has already been sent to the terminal device regardless of whether the data has been updated in the database device.

On the other hand, in the passive operation of the terminal device, as shown in FIG. 8B, the list data is sent from the database device every time the data is updated in the database device. In this case, the list data is only the updated data. The transfer destination of the list data is all the terminal devices communicably connected to the database device regardless of whether the terminal device requests the database device for the list data.

[0006]

However, in the above-mentioned conventional technique, when the terminal device refers to the data in the database device, it is performed by either the active operation of the terminal device or the passive operation of the terminal device. , There was the following inconvenience.

For example, active operation of the above-mentioned terminal device (see FIG.
In (a), all the data including the already acquired unupdated data is transferred to the terminal device of the request destination every time. In other words, since the terminal device does not know the update status of the data in the database device, every time a data request is made,
I was getting duplicate unupdated data. In particular, when a large amount of data is hardly updated, there is a problem in that each element in the system that processes the unupdated data is overloaded, for example, the throughput of the entire system decreases.

On the other hand, in the above-described passive operation of the terminal device (see FIG. 8B), the data is transferred to the terminal device that does not need to refer to the data among the plurality of terminal devices. In other words, since the database device cannot recognize the request status of the terminal device, the update data may be transferred to the terminal device that has not requested the data each time the data is updated. In particular, when there are many terminal devices that have not requested data reference or when there is a large amount of update data, there is a problem that the throughput of the entire system decreases, as in the above case.

As described above, the above-mentioned database system often processes the processed data in duplicate when referring to the list data, and there has been a demand for avoiding the load of the extra data processing. .

The present invention has been made in consideration of the above-mentioned problems of the prior art, and provides a database system capable of efficiently referring to only necessary updated data between a database device and a terminal device. To provide
To aim.

[0011]

In order to achieve the above object, a database system according to the present invention comprises a database device for storing data and at least one terminal device for referring to the data, and the database A device and the terminal device are connected to each other so that they can communicate with each other. The terminal device has data requesting means for transmitting to the database device a data reference request including a data read time at which data was read from the database device at the time of the previous reference request and a given search key item. On the other hand, the database device responds to the data reference request, compares the update time of the data with the data read time included in the data reference request, and selects the data read time from the data. The data reading means for reading the data that has been updated thereafter and matching the search key item, the data read by the data reading means, and the reading time of the data to be used for the next reference are stored in the terminal device. And data transmission means for transmitting to the.

For example, the data is medical text data.

[0013]

According to the present invention, when the terminal device refers to the data of the database device, the data requesting means of the terminal device requests the data reference request including the data read time at the time of the last reference request and the given search key item. Is the database
Be put out. In response to this request, the database device
In, the data reading means, the file of the database system is read, data from this file
Based on the update time of the data reference request and data, the data
Updated after the data read time included in the data reference request
The data is read . Then, the de <br/> over data transmission means of the database device, read data and the data
And the read time of is transmitted to the terminal device. This was sent
The read time is used for the next data request.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In this embodiment, the data is medical, for example, and the data to be handled is text data.

Database system 1 according to this embodiment
1, a database device 2 for storing data and a plurality of terminal devices 4. connected to the database device 2 via a network 3 such as a LAN. ． ． 4 and.

The database device 2 includes, for example, a CPU, a memory, a storage medium (hard disk, optical disk, etc.),
It has an interface and so on. With these hardware configurations, the database device 2 stores data, and the data is stored in the terminal device 4. ． ． 4 can be transferred to each.

That is, the database device 2 creates the index file MI for searching shown in FIG. 2 in the memory and the storage medium and stores the data in this file MI. The file MI is composed of a plurality of records, and each of the plurality of records is provided with two fields (areas of items), that is, a data field and a key field. The data field is composed of at least one data item, and the key field is composed of items for selecting and limiting the range of the record containing the data to be searched, that is, the writing time and the search key item. The write time represents the time when the data item in the same record was updated, and the search key item represents the data item required when further limiting the record selected by the write time.

For example, the search key item shown in FIG. 2 is a case where one item and two items of the data field are targeted. However, this search key item can be omitted when it is not necessary to limit the range of records.

The database device 2 also stores the read time and search data of the index file MI as
Data is temporarily stored in the response buffer (a part of the memory) shown in FIG. 3, and when the search process is completed, the data stored in the response buffer is stored in the terminal device 4. ． ． 4 can be sent.

Terminal 4. ． ． Each of 4 (hereinafter, represented by the terminal 4) includes, for example, a CPU, a memory, a storage medium (hard disk, etc.), an interface, and the like. With these hardware configurations, the terminal device 4 can request the data from the database device 2, and as a result, the acquired data can be displayed on the screen. That is, this terminal 4 creates the same index file MD as the above-mentioned database device 2 in the memory and the storage medium, stores the data in this file MD, and overwrites the updated data. , Can be displayed on the screen. The terminal device 4 also temporarily stores the read time and the search key item described above in a time buffer (a part of the memory), and stores the data stored in the time buffer when requesting the next data. It can be transmitted to the database device 2.

Next, the data selection processing by the database device 2 will be described with reference to FIG. In addition, this FIG.
The processing shown in (1) constitutes the data reading means and the data transmitting means of the present invention.

First, in step S1, a data request is received from the terminal device 4. This request includes the read time = Ti at the time of the previous request and the search key item as the key information. Next, at step S2, time of key information = T
With reference to i, the record (data) accessed for writing (updated) after that time is selected (searched). That is, the target is sequentially from the record Ri + 1 corresponding to the write time = Ti + 1 next to the time = Ti,
Each writing time = Ti + 2 ,. ． ． , Tn (Ti <Ti
+1 <Ti + 2 <. ． ． Each record Ri + 2 ,. ． ． , Rn. For example, when there are two target update records, i + 2 = n, and the update record Ri + 1 at the write time = Ti + 1 and the update record Ri + 2 at the write time = Ti + 2 (= Tn).
(= Rn) is the selection target.

Next, the initial value of the counter cnt is sequentially set to i + 1 in step S3 in order to perform the data selection process in the order of the above-mentioned writing time. Next, in step S4, the index file MI is read, and the read time = Tna (Tn <Tna) is added to the reply buffer as time data for the next request. Next, in step S5, a record Rcn corresponding to the write time = Tcnt in the key field of the index file MI.
By referring to the search key item of t, it is determined whether or not it matches the search key item of the key information. For example, initially c
Since nt = i + 1 is set, write time = T
The record Ri + 1 corresponding to i + 1 is the target of the determination in step S5.

If YES is determined in step S5, the data of the record Rcnt is added to the reply buffer in step 6, and the process proceeds to step S7. On the other hand, if NO in step S5, the process proceeds to step S7,
The value of the counter cnt is incremented (+1). Next, it is determined whether or not the set value regarding the counter cnt exceeds n in step S8 (whether or not the record Rn corresponding to the write time = Tn has been processed). If YES is determined in this step S8, the read time = Tna added to the response buffer and the selection data are sent to the terminal device 4 in step 9, while if NO is determined in step S8, the process proceeds to step S5. The process returns and the same processing as described above is repeated.

Next, the data request processing by the terminal device 4 will be described with reference to FIG. The process shown in FIG. 5 constitutes the main part of the data requesting means of the present invention.

First, in step S21, the data requested this time is received. Next, in step S22, the read time of the index file MI in the received data is held in the time buffer for use in the next request. Then, in step S23, the selected data in the received data is overwritten (overwritten) on the record in the index file MD corresponding to the selected data, and in step S24.
Display the updated data on the screen.

Then, in step S25, it is determined whether to request data. This determination is made based on whether or not a manual operation such as a key input is performed after an appropriate time has elapsed. This appropriate time can be freely adjusted by the system user in consideration of, for example, a time zone in which the data in the database device 2 is frequently updated. If it is determined in step S25 that there is a manual operation requesting data (YES), step S25
At step 26, the database device 2 is requested for update data, while at step S25, there is no operation for requesting data (N
If it is determined to be O), the process returns to the same step S25 and the same processing as described above is repeated.

Next, the overall operation will be described with reference to FIGS. 6 and 7.

FIG. 6 shows the database device 2 and the terminal device 4.
And the processing of data requests and responses according to time and time.

First, in step S31, the terminal device 4
Requests the database device 2 for the initial state. This request targets all data stored in the database device 2 up to the present time. Next, when the database device 2 receives the request in step S32, it reads the index file MI in step S33.
This read time = T1 is temporarily stored in the reply buffer. Next, in step S34, the database device 2 transmits time = T1 and all data in the initial state to the terminal device 4. When this data is received by the terminal 4 in step S35, the time = T1 is held in the time buffer (transmission buffer memory) in the terminal device for the next request in step S36.

Here, after the elapse of an appropriate fixed time, the terminal device 4 requests the data updated after time = T1 in step S37. Next, when the database device 2 receives the request in step S38, the database device 2 reads the index file MI in step S39. This read time = T2 is temporarily stored in the reply buffer. Next, in step S40, the database device 2 transmits the read time = T2 and the update data to the terminal device 4. This data is used in step S4.
When it is received by the terminal device 4 at 1, the read time = T2 is held in the time buffer for the next request at step S42.

When the above series of data exchanges are repeated, the flow generally becomes as follows. That is, in step S43, the terminal device 4 requests the database device for the data updated after the time Ti. Next, when the database device 2 receives the request in step S44,
In step S45, the index file MI is read. This read time = Ti + 1 is temporarily stored in the reply buffer. Next, in step S46, the database device 2 transmits time = Ti + 1 and update data to the terminal device 4. When this data is received by the terminal device 4 in step S47, time = T in step S48.
i + 1 is held in the time buffer for the next request.

For example, as shown in FIG. 7, time = Tn-
It is assumed that the data of the second and third records of the index file MI in the database device 2 are updated during the time = Tn + 2. At this point, if there is a request for update data from the terminal device 4, the database device 2 starts the above-mentioned processing, reads the index file MI, and holds the read time = Tn + 2a (> Tn + 2) in the reply buffer. To do. Then, the data of the second and third records updated after time = Tn is searched, added to the reply buffer, and the data is transmitted to the terminal device 4. When the terminal device 4 receives the data, the terminal device 4 starts the above-mentioned processing, holds the time = Tn + 2a in the time buffer for the next request, and stores the second time in the index file MD.
And the third record data are overwritten and displayed on the screen.

The database system according to the above-described embodiment requests list data by active operation of the terminal device (see FIG. 8A), and the list data sent in response to this request is not all data. , Passive operation of terminal devices (Fig. 8
It is the data only for the update by (see (b)).

Therefore, the data is apparently processed as if the data request of the terminal device and the data update of the database device are synchronized, and in reality, the data request is not performed every data update of the database device. The list data is requested from the terminal device at every adjusted appropriate time interval, and the minimum necessary updated data is sent from the database device only to the requesting terminal device. As a result, it is possible to efficiently refer to the list data without duplicating the data that has not been updated, and reduce the load of data processing that increases in proportion to the number of installed terminal devices, the amount of data, and the data update frequency. Like

Next, a specific application example of the database system according to the above embodiment will be described below.

For example, an example of application of this type of database system is a radiology department information system. This radiology information system is a database device that manages basic information (reservation / acceptance information, examination execution information, etc.) of patients who are to be examined in the radiology department of a hospital, and the database device, for example, via a network such as a LAN. It is configured to include a plurality of connected terminal devices. In general, this system is operated by providing a database device in a radiology data processing room and the like, and providing terminal devices in a radiology examination reception room, an image reading room, a plurality of image diagnostic examination rooms and the like.

In this radiology information system, for example,
Since it is possible to easily refer to and monitor the patient's examination implementation status and image interpretation implementation status with the terminal device in the examination reception room, it is possible to efficiently grasp information such as whether or not the examination and image interpretation are completed, and to improve patient diagnosis efficiency. The throughput of the entire system including the system will be improved.

Not only the radiology information system,
It can be applied to a hospital information system that handles basic information on patients for the entire hospital.

Furthermore, the medical image archiving communication system for archiving and communicating the image data obtained by the image diagnostic examination of the radiology department can be applied to the processing of the text data accompanying the image data.

Further, the database system according to the present invention is not limited to the above-mentioned various medical database systems, but generally, the database device stores and manages text data that changes in time series, and stores the data. It can be applied to a database system in which a terminal device refers to and monitors the change status.

For example, the database system according to the present invention may be applied to a database system that manages and monitors changes in the entry and exit of vehicles in a parking lot.

In the above embodiment, when referring to the data in the database from the terminal device, it is requested by a manual operation at appropriate time intervals (for example, T1 and T2 in FIG. 6). Then, the request may be made at a preset time interval by automatic operation. It is also possible to provide both manual and automatic operations at the same time.

[0044]

As described above, according to the database system of the present invention, when the terminal device refers to the list data of the database device, it can be freely adjusted by the terminal device, and the required minimum is set at appropriate time intervals. It is possible to refer to only the data for the update, and it is possible to avoid the load of data processing that increases in proportion to the number of installed terminal devices, the amount of data, and the frequency of data update.

[Brief description of drawings]

FIG. 1 is a schematic hardware configuration diagram of a database system according to an embodiment.

FIG. 2 is a diagram showing an example of an index file in a database device.

FIG. 3 is a diagram showing an example of a reply buffer in the database device.

FIG. 4 is a schematic flowchart showing a data selection control process.

FIG. 5 is a schematic flowchart showing a process of requesting data.

FIG. 6 is a diagram showing data exchange between a database device and a terminal device along with time change.

FIG. 7 is a diagram showing an index file and a data storage state in a buffer according to the operation of the embodiment.

8A and 8B are diagrams showing a data reference method of a database system according to a conventional technique, FIG. 8A is a schematic diagram of a method by active operation of a terminal device, and FIG. 8B is a schematic diagram of a method by passive operation of a terminal device.

[Explanation of symbols]

1 database system 2 Database device 3 network 4 terminal devices Index file in MI database device Index file in MD terminal device

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-4-305751 (JP, A) JP-A-2-23437 (JP, A) JP-A-4-165437 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G06F 17/30 G06F 12/00 JISST file (JOIS)

Claims (2)

(57) [Claims] 1. A database device for storing data,
A database system comprising at least one terminal device for referencing the data, wherein the database device and the terminal device are communicably connected to each other , wherein the terminal device has the database at the time of a previous reference request.
The data reference request including the retrieval key items and give al data read time read data from the device comprises a data requesting means for transmitting to said database device, said database apparatus, in response to the data reference request The update time of the data and the data reference request.
By comparing the data read time
Updated from the data after the data read time
Read the data that matches the search key item
Data read-out means to be read out and read-out by this data read-out means
Yes and data transmitting means for transmitting the read <br/> out time of the data to the terminal device used in the was Desa data only next reference
A database system characterized by: 2. The database system according to claim 1, wherein the data is medical text data.