JPH02196338A - Data base access system - Google Patents

Abstract

PURPOSE:To process the requests in the order of higher priority ranks by adding the priority information on the requests into the request information received by an access mechanism from a data base control system and performing the allocation according to the priority information. CONSTITUTION:An access mechanism 1-5 receives the request information from a data base control system DBMS 1-4 and processes the requests in the order of higher priority ranks via a data base DB machine 1-2 by reference to the priority information contained in the request information. In this case, it is automatically decided whether the machine 1-2 should be monopolized or not based on the load situation (using state) of the machine 1-2. In other words, the machine 1-2 is monopolized until the processes are through with all requests given from the DBMS 1-4 as long as the machine 1-2 is not busy. In the case the machine 1-2 is busy, the requests are divided into plural page groups and the machine 1-2 is used (not monopolized) alternately with the requests received from other DBMSs. Thus the requests given from the DBMS 104 are processed in the order of higher priority ranks.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a data input/output method, and in particular to a database management system (DataBa5e Mana
gement system, hereinafter referred to as “D B
A database machine (hereinafter referred to as r
The present invention relates to a database access method for data input/output, which has a DB machine (referred to as a DB machine).

[Prior Art] As a conventional database access method, for example, rH
ITACM series processing equipment 80802-001” (
The method shown in pages 263 to 284 is known. In this method, when an input/output request occurs from an application, the host computer performs input/output processing based on the physical location of the input data, the length of the input data, and the buffer address in main memory for receiving the input data. had issued a request.

Furthermore, recently, data input/output systems have been developed that include a DB machine that can perform DB operations (database operations) during data transfer.

This DB machine is provided for each external storage device (auxiliary storage device) (on the external storage device side rather than the channel device), and selects and edits data that matches the conditions of the data to be transferred. It is a machine with functions.

The conventional database access method described above does not include this DB machine, and does not take into account input/output requests in a system equipped with a DB machine.

[Problem to be solved by the invention] In the conventional database access method described above, no consideration is given to the method of issuing input/output requests to the DB machine, so the DBMS side independently creates a dedicated channel suitable for the processing mode. Create a command word group (CCW),
There was a problem in that input/output requests had to be made through an interface at the input/output supervisor level, which specialized in input/output within O8.

Also, when issuing input/output requests using the B machine, when input/output requests for high-priority data that needs to be obtained immediately and for low-priority data that are not very urgent, What type of input/output request format should an input/output request be made to a DB machine? Furthermore, what type of request format should an input/output request be made to a DB machine when the DB machine is relatively idle or relatively busy? Until now, no consideration had been given to whether the

Accordingly, an object of the present invention is to provide a database access method that specifically handles input/output requests of a DB machine and enables the use of the DB machine using an interface at the data management level of O8.

Another object of the present invention is to provide a database access method that, in addition to the above database access method, schedules input/output requests so that efficient and appropriate input/output is performed according to the priority order of the input/output requests. .

Another object of the present invention is to provide a DB machine access method that efficiently and optimally schedules input/output requests and optimally allocates B machines depending on the availability of the DB machines.

[Means for Solving the Problems] In order to achieve the above object, the database access method of the present invention includes a host divider, an auxiliary storage device (which constructs the database), and a auxiliary storage device located on the side of the auxiliary storage device. A database machine that performs calculation processing such as editing transferred data (
DB machine), a database management system (DBMS) on the host computer side, and an access mechanism.The feature is that priority information indicating the priority is added to requests issued from the DBMS to the access mechanism. , so that the processing for the request is executed according to this priority order.

Also, when receiving a request from the DBMS, the usage status (load status) of the DB machine is checked, and if it is free, the DB machine is used exclusively until all requests have been processed, and when it is busy, the DB machine is used exclusively for processing requests. The existing page is divided into multiple page groups and configured to be used alternately with requests from other database management systems.

[Effect] The effect based on the above configuration will be explained.

When the access mechanism receives request information from the DBMS,
The priority information in the request is looked at and the DB machine processes the requests in order of priority. At this time, the load status (usage status) of the DB machine is checked and it is automatically determined whether the DB machine is to be used exclusively or non-exclusively. In other words, if the DB machine is free, the DB machine will be used exclusively until all requests from the DBMS have been processed, and if the DB machine is busy, the requests will be divided into multiple page groups and other pages will be processed. The DB machine is used (non-exclusively) in exchange for requests from the DBMS.

As a result, among requests from the DBMS, requests with higher priority can be processed faster, and the access method becomes the most efficient depending on the load status of the DB machine.

[Example 1] An example of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is an overall configuration diagram of a DB machine access system according to an embodiment of the present invention. 1-1 is a host computer, especially its I10 management unit (input/output management unit), and necessary information is stored in the main memory. It is designed to be stored in . host computer 1
-1, DBMS l-4 and access mechanism 1-5 are in operation. DBMSl-4 sends various request information 1-6, 1. -7.1-8.・ ・Stores
Calculation requests 1-9.1-10, 11 based on the request information
1, . . . is issued to the access mechanism 1-5. The access mechanism 1-5 includes a scheduler 1-12 that receives an arithmetic request and issues a corresponding l10 (input/output) request 1-14 to the channel, and a scheduler 1-12 that receives a calculation request and issues a corresponding l10 (input/output) request 1-14 to the channel. DB machine load status check unit 1- that can check the status (how many people are using the same DB machine, how many requests are coming in, etc.)
13.

Reference numeral 1-2 denotes an I)B machine, which has a request reception port 1-15 including a request reception area, and a data transfer calculation section 1-16 that performs calculations such as data processing and editing. As a result, when the DB machine 1-2 transfers data from the auxiliary storage device (external storage device 1-3) described later to the host computer 1-1, the DB machine 1-2 includes records that meet the conditions in synchronization with the data transfer. The 6DB machine 1-2 is the host computer 1-1, which performs page selection processing in which pages are selected and output, and compressed page output processing in which only designated fields of records that meet conditions are edited and output in page format. The I10 request 1-14 is received by the request reception port 1-15 via the channel.

It is assumed that the DB machine 1-2 can process only one I10 request at a time (multiple requests can be accepted at the same time in the request receiving area).The DB machine 1-2 is an auxiliary storage medium (
An external storage device (for example, a disk device), which includes a database 1-17 and a storage medium drive unit (not shown).
(drive device) and a control unit (control device). Further, it is assumed that one or more external storage devices 1-3 are provided, and a DB machine 1-2 is provided corresponding to each external storage device.

Now, when the ■/○ request 1-14 is received by the request port 1-15, the requested data from the database 1-17 in the auxiliary storage medium 1-3 is retrieved and transferred. Calculation (editing, etc.) by data transfer calculation unit 1-16
will be carried out.

Here, request information 1-6 to 1 when issuing an operation request 1-9 from the DBMS l-4 to the access mechanism 1-5.
-8 details are shown in Figure 2. In Figure 2, 2-6 is request information (corresponding to one of 1-6 to 1-8 in Figure 1);
-1 is the calculation target information (for example, "from what page to what page" or which table is to be calculated, etc.),
2-2 is processing condition information (for example, a description of what conditions records are to be processed, such as “how old or older”);
2-3 is output format information (for example, whether to output as is,
2-4 is reception area information (information describing to which area the results are to be received). Further, 2-5 is priority information (for example, whether or not the data is urgently needed) newly provided as a feature of this embodiment.

FIG. 3 is a detailed diagram for explaining the task configuration and processing flow in the access mechanism 1-5.

In FIG. 3, the access mechanism 1-5 has a request receiving interface 3-5.
1. Requirement analysis task 3-2. and DB machine access task 3-3.

When the request reception task 3-1 receives the calculation requests 1-9 to 1-11 from the DBMSI-4 (3-10), the request reception task 3-1 records the information with the larger value of the priority information 2-5 in the transfer request queue registration table 3-4. The requests are sequentially queued in the transfer request queue 3-5 (3-11).

There are a plurality of request analysis tasks 3-2, each of which performs the same operation. 3-12) Each task retrieves the first transfer request queue 3-5 from the transfer request queue registration table 3-4.
Analyze the request (3-13). Then, check the load on the DB machine (3-14), and if the load is low, request I10 for all requested calculation targets at once (3-14).
-15).

If the load is large, divide the calculation target 3-16), and perform the calculation in each divided unit (in principle, one page is the unit).
The I10 request is made multiple times (3-17).

When a work/○ request is made in request task 3-2, I10
The requests are queued in order in the request queue registration table 3-6 as a 10 request queue 3-7.

A number of DB machine access tasks 3-3 are provided corresponding to the number of possible simultaneous I10 receptions of the DB machine, and each task corresponds one-to-one with a request reception port of the DB machine. This task 3-3 takes out the I10 request queue at the top of the ■/○ request queue registration table 3-6 (3-18) and issues I/○ to the DB machine (3-18).
-19).

According to this embodiment, requests with higher priorities are processed first. Also, when a request is received from the DBMS to the access mechanism, the usage status (load status) of the DB machine is checked, and depending on the load on the DB machine, it is automatically decided whether to use it exclusively or non-exclusively. judge accordingly. That is, the DB
If the machine is free (when the load is light), the DB machine is used exclusively while all requested pages are received. On the other hand, if the DB machine is busy processing multiple requests (when the load is heavy), all requested pages are divided into multiple page groups and requests from other DBMSs are processed in turn. Use the DB machine non-exclusively. Therefore, appropriate and efficient input/output processing can be performed depending on the priority and the usage status of the DB machine.

[Effects of the Invention] As explained above in detail, according to the present invention, in an access method equipped with a DB machine that can perform editing output at the stage of transferring data from an auxiliary storage medium,
A request requested by the BMS with a higher priority can be processed more quickly. Also, depending on the load status of the DB machine, when the load is not high, the DBM
When the DB machine is used exclusively and under load until all requests requested by S have been processed,
By performing split page processing as non-exclusive, it is possible to avoid the situation where the DBMS is exclusively used to process requests from one DBMS and requests from other DBMSs cannot be processed, so the DB machine can be used efficiently. , has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a DB machine access system according to an embodiment of the present invention, FIG. 2 is a configuration diagram of request information, and FIG. 3 is a diagram for explaining the details of tasks and processing flow in the access mechanism. be. 1-1...Host computer, 1-2...
DB machine, 1-3... Auxiliary storage medium, 1-4
... DBMS, 1-5 ... Access mechanism, 2-1 ... Computation target information, 2-2 ... Processing condition information, 2-3 ・ Output format information , 2-4...
...Reception area information, 2-5...Priority information,
3-1...Request reception task, 32...Request analysis task, 3-3...DB machine access task.

Claims (1)

[Scope of Claims] 1. A host computer, an auxiliary storage device having a database, and an auxiliary storage device located on the side of the auxiliary storage device, which performs editing processing on the data when transferring the data from the auxiliary storage device to the host computer. In the database access method, the database access method includes a database machine, a database management system that manages a database on a host computer side, and an access mechanism that assigns a request from the database management system to be executed on the database machine on the host computer side. A database access method characterized in that the access mechanism is configured to add priority information indicating the priority of requests to the request information received from the database management system, and perform the allocation according to the priority information. . 2. When the access mechanism receives a request from the database management system, it checks the usage status of the database machine, and if the database machine is free, uses the database machine exclusively until all requests are processed. However, when the database machine is busy, requested pages are divided into a plurality of page groups, and the database machine is used in turn with requests from other database management systems. The database access method described in 1.