JPH03255549A - Record exclusion system - Google Patents

Abstract

PURPOSE:To improve the processing efficiency by permitting a reference and updating in the case no influence is exerted on a record position of the other record by updating of one record, even if the reference and updating are generated in the record in the same page. CONSTITUTION:This system is constituted of a record exclusion mechanism 11 for receiving a file processing request 10, and a reference information storage area 15, and the record exclusion mechanism 11 is constituted of a record retrieving means 12, a lock deciding means 13 and a reference position managing means 14. In such a state, at the time of reference and updating, the record retrieving means 12 determines the position of an object record, the lock deciding means 13 refers to the reference information storage area 15 and decides the propriety of the reference and updating to the target record, and the reference position managing means 14 manages the information of the reference information storage area 15. Accordingly, even in the case the reference and updating of the record in the same page are overlapped, the parallel processing can be executed to the utmost. In such a manner, the generation of waiting is decreased and the efficiency of the system is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a record exclusion method in a file management system for a computer system.

[Prior Art] Conventionally, in a file management system in which reference updates are performed by multiple processes and the update process can be dynamically discarded,
In a file structure in which records are not physically moved due to record updates (additions/deletions), exclusive control on a record-by-record basis is possible.

However, like an index file, it has a file structure that partitions the auxiliary storage device into physical pages, physically arranges records within the page in the order of logical values (key values), and updates the records. In a system with a file structure in which the physical location of records is moved by
Exclusive control on a record-by-record basis as described above was not possible, and exclusive control was performed on pages, which were physical partition units of a file. In other words, the result of updating a certain record in a certain page will affect the physical position of other records in the same page, making it impossible to perform exclusive control that specifies the record position.

[Problems to be Solved by the Invention] As described above, the system has a file structure that physically manages page partitions on an auxiliary storage device and physically arranges records within pages in the order of logical values. For files where multiple processes simultaneously issue reference update requests, the only option is to perform exclusive control on pages, which are the physical partition units of the file, and when adding a record to a page or deleting a record from a page. , all reference updates to the page will have to wait until the processing for the page is completed, and the processing for all records stored in the page will be delayed until the processing is completed just by adding and deleting the Lou code. There was a problem with this.

In particular, in file management systems that allow dynamic cancellation of update processing when a failure occurs during processing or when a cancellation request is issued from an application program, references from other parties are not allowed until the processing is finalized and there is no possibility of cancellation. Since update requests have to wait, there is a drawback that the efficiency of the system cannot be improved.

The present invention has been proposed in view of the above points, and its purpose is to enable parallel processing as much as possible and reduce the occurrence of waiting even when references and updates of records within the same page overlap. The object of the present invention is to provide a record exclusion method that can improve system efficiency.

[Means to solve the problem]

The present invention is a distant relative of the above object, and has a file structure in which partitions on an auxiliary storage device are managed using physical pages, and records are physically arranged in the order of logical values within the pages. In a file management system where reference update requests are generated simultaneously from multiple processes, there is provided a record search means for determining the position of the target record during reference update, and whether or not the reference update for the target record is possible by referring to the reference information storage area. The storage device includes a lock determination device that determines the lock status, and a reference position management device that manages information in the reference information storage area.

(Operation) In the record exclusive method of the present invention, at the time of reference update, the record search means determines the position of the target record, and the lock determination means refers to the reference information storage area to determine whether reference update to the target record is possible. The reference position management means then manages the information in the reference information storage area.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the constituent countries of an embodiment of the record exclusion system of the present invention. Note that an index file is taken as an example of the target file.

In FIG. 1, this embodiment is comprised of a record exclusion mechanism 11 that receives a file processing request 10, and a reference information storage area 15. Furthermore, the record exclusion mechanism 11 is composed of a record search means 12, a lock determination means 13, and a reference position management means 14, and the reference information storage area 15 stores record reference position information 16.17 and a record reference position information group 18. include. The functions of each part are as follows.

Record reference position information 16: Information on the record for which processing has been requested is temporarily stored, and as shown in Figure 2, the page number 21 where the record is stored, the record position 22, and the reference mode (exclusive , shared) 23.

Record reference position information group 18: A collection of record reference position information of records that are currently being referenced and updated. Each record reference position information has the format shown in FIG.

Record reference position information 17; Record reference position information group 1
The record reference position information extracted from No. 8 for comparison is temporarily stored.

Record search means 12: Upon receiving the file processing request ■○, determines the target record reference position, and stores the determined information as record reference position information 16. Details of the process are shown in FIG.

Lock determination means 13; extracts record reference position information one by one from the record reference position information group 18;
Reference position information 17 Stores record reference position information 1
6, it is determined whether the file processing request IO can be executed, and if it can be executed, the reference update is permitted, otherwise the request is rejected. Details of the process are shown in FIG.

Reference position management means 14: When reference update is permitted, record reference position information 16 is newly added to the record reference position information group 18, and stored and managed in the reference information storage area 15.

Details of the process are shown in FIG.

The operation of the embodiment shown in FIG. 1 will be explained below along with the flowcharts shown in FIGS. 3, 4, and 6.

First, the record search means 12, as shown in FIG.
1st time 2nd load the top index page (step 31)
).

Next, records in the index page are searched by key value to determine the target record (step 32).

Then, it is determined whether or not it is the target page, that is, the lowest index page (step 33), and if the target page is wide (NO in step 33), the process returns to step 31 and the next index page is read. .

If it is the target page (YES in step 33), the record position determined in step 32 is stored in the record reference position information 16 (step 34), and the process ends.

Next, as shown in FIG. 4, the lock determination means 13 starts processing in response to the determination request 40, and first extracts one record reference position information from the record reference position information group 18. It is stored in the record reference position information 17 (step 41).

Next, it is determined whether or not all of the record reference position information group 18 has been processed (step 42), and if all have been processed (YES in step 42), an OK (reference update is allowed) is returned to the request source. Step 48), the process ends.

If not all have been processed (NO in step 42), record reference position information 16 and record reference position information 1
Compare the page numbers of 7.

If the page numbers are not equal (Step 43), the page numbers are not equal (Step 43).

If step 43 is NO, the process returns to step 7 step 41.

If the page numbers are the same (YES in step 43), record reference position information 16 and record reference position information 1
7 reference mode (step 44), if both are exclusive (YES in step 44), the request source is denied (step 44).
Step 49) in which the reference update is rejected) is returned, and the process ends.

If both are not exclusive (NO in step 44),
Record reference position information 16 and record reference position information 17
Further compare the reference modes of step 45), and if both are shared (YES in step 45), step 4
Return to 1.

If both are not shared (NO in Step 45),
Record reference position information 16 and record reference position information 17
Determine the reference mote of and assign the shared record position to variable m and the exclusive record position to variable n (
Step 46).

Next, compare the set variables m and n (step 47), and if m≧n (YES in step 47),
Step 49) returns a negative response to the request source, and the process ends.

In other cases (No in step 47), the process returns to step 41.

The relationship between the reference update processing request and the processing availability in the above processing is illustrated in FIG. 5.

Next, the reference position management means 14, as shown in FIG.
Processing is started in response to the reference position storage request 60, and first, a storage location where the last record reference position information is stored is searched from the record reference position information group 18 in the reference information storage area 15 (step).

Pro 1).

Next, the content of the record reference position information 16 is stored next to the storage location of the last searched record reference position information (step 62), and the process is terminated.

Next, explanation will be given using a specific example.

FIG. 7 shows an index page 70 that constitutes an index file, and now, as shown in the chronological order of FIG. 8, a processing request to add a record 76 with a key value "C" is generated. Then the key value IB.

Consider a case where a processing request to search (reference) a record 72 having a munikey value "C" is generated, and a processing request to add a record 76 having a munikey value "C" is subsequently cancelled.

Conventionally, the auxiliary storage device has a file structure in which partitions are managed using physical pages, and records are physically arranged in the order of logical values within the page. In a file management system that simultaneously generates files from processes, exclusive control is performed on a page-by-page basis, and therefore the key value "C
” before completing the processing request to add record 76 with “
The search for the record 72 with the key value "rB" belonging to the same index page 70 was rejected unconditionally, but in the present invention, the following processing is performed in response to a search request for the record 72 with the key value rB. It will be done.

(2) The record search means 12 searches the index page 70 and determines the record position 78 of the record 172 having the key value "B".

■The lock determination means 13 extracts the record reference position information related to the record mallo with the key (I'CJ) belonging to the same index page 70 from the record reference position information group 18, and determines that the reference mode is exclusive and the key value rB. If the request for is shared, compare the record positions of both,
If the record position on the exclusive side is large, references are allowed. In this case, the record position where the record 76 with the key value "C" is added is 79, and the record position of the record 72 with the key value "B" is 78, so the key value r
Reference to the record 72 with B is permitted.

In this example, by adding record 76 with key value "C" to record position 79, record 73
74.75 will be shifted backward by the additional size, but this is unrelated to the record position 7th of the record 72 with the key value rB, so the processing is performed normally.

Also, the processing request to add record 76 with the key value "CJ" was subsequently canceled, and records 73, 74.75
Even if the key value "rB" is shifted forward by the additional canceled size, the processing is performed normally because it is irrelevant to the record position 78 of the record 72 with the key value "rB".

〔Effect of the invention〕

As explained above, in the record exclusion method of the present invention, even if an al update occurs in a record within the same page,
Reference updates are allowed when updating one record does not affect the record position of the other record, increasing the probability that parallel operations will be possible and improving processing efficiency. .

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the record exclusion method of the present invention, FIG. 2 is a logical block diagram of the record reference position information in FIG. 1, and FIG. 3 is the processing of the record search means in FIG. 1. 4 is a flowchart of the processing of the lock determination means in FIG. 1, FIG. 5 is a diagram showing the relationship between a processing request and whether processing is possible, and FIG. 6 is a flowchart of the processing of the reference position management means in FIG. 1. The flowchart and FIGS. 7 and 8 are diagrams showing specific examples of processing. In the figure, 11... Record exclusion mechanism 12.
......Record search means 13...!
......Lock determination means 14...
...Reference position management means l5...
・Reference information storage area 16 17...Record reference position information

Claims (2)

[Claims] (1) Manage partitions on the auxiliary storage device using physical pages,
In a file management system that has a file structure that physically arranges records in the order of logical values within a page, and in which reference update requests for records occur simultaneously from multiple processes, the position of the target record is determined at the time of reference update. A lock determining means refers to a reference information storage area to determine whether or not a target record can be referenced and updated, and a reference position management means manages information in the reference information storage area. Record exclusion method. (2) The lock determination means is used when no reference update is performed for other records in the same page as the target record, and when multiple records in the same page that are reference updated are all in shared mode. According to claim 1, it is determined that the reference update is possible in the case where the record position in the exclusive mode is larger than the record position in the shared mode among the plurality of records to be reference updated in the same page. record exclusion method.