JP2586330B2 - Logical deletion data management method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention does not allow duplication of the key value of a data record in a file, and stores logical deletion information in a data record requested to be logically deleted in response to a logical deletion request from an application program. Regarding a file management system that logically deletes a data record requested to be logically deleted by changing it to one that indicates logical deletion, the application program itself is particularly conscious of the application program that is the data record storage request source. Even if there is a logically deleted data record in the file that has the same key value as the key value of the data record to be stored this time, physically delete the logically deleted data record. Logical deletion data that can store new data records. It related to data management method.

[0002]

2. Description of the Related Art Conventionally, logical deletion information indicating whether logical deletion has been performed is set in a data record managed by a key value, and a logical deletion of a data record having a certain key value is requested from an application program. If done,
The data record is logically deleted by changing the logical deletion information in the data record requested to be logically deleted to indicate the logical deletion completed. By performing such a logical deletion, the deletion performance can be made higher than in the case of performing the physical deletion.

In a conventional file management system capable of performing the above-described logical deletion and not allowing duplication of key values of data records stored in a file, a data record is newly stored in a file. In such a case, the following processing is performed.

When storing a data record in a file, if there is no logically deleted data record whose key value matches the data record to be stored this time in the file, the application program stores the data record in the file. Make a request to the management system. The file management system stores the data record in a file in response to the request.

If there is no logically deleted data record whose key value matches the data record to be stored this time in the file, the data record can be newly stored as described above. However, when there is a logically deleted data record having the same key value, the data record cannot be stored as it is, assuming that duplication of the key value of the data record is not allowed. Therefore, in such a case, the application program requests the file management system to physically delete the logically deleted data record, and then requests the file management system to store the data record. In response to this request, the file management system physically deletes the data record requested to be physically deleted, and then stores the data record requested to be stored in the file.

[0006]

As described above, conventionally, when a data record is stored in a file, a logically deleted data record having the same key value as that of the data record exists in the file. In such a case, since the data record cannot be stored until the contents of the file, the logically deleted data record must be physically deleted, which causes a problem that the processing speed is reduced.

[0007] Further, since a process for preventing duplication of key values must be incorporated in the application program, there is a problem that productivity in developing the application program is low.

Accordingly, an object of the present invention is to provide a logically deleted data record having the same key value as a key value of a data record to be newly stored, which is conscious of the application program itself, as viewed from the application program itself. It is an object of the present invention to provide a logically deleted data management method which does not require physical deletion of a logically deleted data record even if it exists, and which can increase productivity when developing an application program.

[0009]

In order to achieve the above object, the present invention provides a file management system which does not allow duplication of key values of data records in a file. A primary key corresponding to the key being conscious, a suffix for making the key value of the same data record unique, and a suffix for making the key value of the same data record unique. The file management system includes a current suffix indicating a storage order and logical deletion information indicating whether or not the file has been logically deleted. Of the stored data records, the key value specified by the application program is the primary key. Data record logical deletion means for setting the logical deletion information of the data record whose logical value has been set to the initial value as the suffix, and a primary key in response to a data record storage request from the application program. If a key value that the application program is aware of as a key value of the data record is set, and a logically deleted data record whose initial value is set in a suffix exists in the file, A suffix that changes the value of the suffix of the data record based on the value set in the current suffix of the data record, outputs the suffix value after the change, and outputs the initial value of the current suffix if it does not exist. Management means, and the suffix management means When the values are output, the data record requested by the application program to be stored is replaced with the primary key, suffix, and current suffix values of the key value, the initial value of the current suffix, and the current suffix, respectively. A data record storage unit that stores the data record of the value output by the suffix management unit in the file, and a search request that specifies a key value for a data record that is not logically deleted from the application program is output. In this case, the file is searched by a search key having the primary key value as the key value designated by the application program and the suffix value as its initial value, so that the application program is stored in the primary key from the file. A data record search means for searching for a data record which is not logically deleted and has a key value designated by the RAM and whose initial value is set in the suffix.

According to the present invention, in order to achieve the object of enabling reuse of a logically deleted data record, the data record search means searches for a logically deleted data record from the application program. By outputting a search request specifying a key value, the value of the suffix in the search key is changed with the primary key value as the key value specified by the application program for each search, and the file is changed. Search and
The file is searched for a logically deleted data record in which the key value specified by the application program is set as the primary key.

Further, according to the present invention, in order to achieve the object of enabling unnecessary data records to be deleted when the file capacity becomes insufficient, a physical deletion request is issued from the file in response to a physical deletion request from the application program. A data record physical deletion means for physically deleting the data record requested to be deleted is provided.

[0012]

The key items of the data record in the file are the primary key corresponding to the key that the application program is aware of, and the suffix to make the key value of the data record with the same primary key unique. It is composed of Further, the data record has a current suffix indicating the storage order of the primary keys in the same data record and logical deletion information indicating whether or not the logical key has been logically deleted.

When a logical deletion request specifying a key value is output from the application program, the data record logical deletion means sets the primary key to the key value specified by the application program and sets the suffix to the initial value. The logical deletion information of the data record being deleted is changed to information indicating that logical deletion has been completed.

When a data record storage request is output from the application program, the key value that the application program is aware of as the key value of the data record is set as the primary key, and the initial value is set as the suffix. If the logically deleted data record is present in the file, the suffix management means changes the suffix value of the data record based on the current suffix value of the data record and the suffix value after the change. Is output, and if not, the suffix management means outputs the initial value of the current suffix.

When the value is output from the suffix management means, the data record storage means recognizes the data record which the application program is going to store in the file, with the values of the primary key, suffix, and current suffix being recognized by the application program. The key value, the initial value of the current suffix, and the value output by the suffix management means are stored in a file as a data record.

When a search request specifying a key value for outputting a data record that has not been logically deleted from the application program is output, the data record search means sets the primary key value to the key specified by the application program. The file is searched using the search key with the value and suffix value as its initial values. In addition, when a search request specifying a key value is output to search for a logically deleted data record, the data record search unit sets the value of the primary key to the key specified by the application program for each search. Change the value of the suffix in the search key as the value and search for the file.

When a physical deletion request is issued from the application program, the data record physical deletion means physically deletes the data record requested to be physically deleted.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, which comprises a file management system 1, a file 2, and an application program 3.

The data records stored in file 2 are identification information 21, primary key 22, suffix 2
3, a current suffix 24, and data 25.

The identification information 21 includes logical deletion information indicating whether the data record has been logically deleted, and the storage time of the data record.

The primary key 22 and the suffix 23 are key items. The primary key 22 corresponds to a key value recognized by the application program 3, and the suffix 23 represents a key value of a data record having the same primary key 22 value. It is an item to make it unique.

The current suffix 24 is an item used to determine the value of the suffix, and indicates the storage order of data records having the same primary key.

The file management system 1 is a system which does not allow duplication of key values of data records in the file 2, and includes a data record logical deletion unit 11, a data record physical deletion unit 12, and a data record search unit 13.
, A suffix management unit 14, a data record storage unit 15, an instruction identification information unit 16, a key unit 17, and a suffix unit 18.

When the position information is passed from the application program 3, the data record logical deletion means 11 logically deletes the logical deletion information included in the identification information 21 of the data record in the file 2 indicated by the position information. It has a function of changing to “DELETE” indicating that the processing has been completed.

The data record physical deletion means 12 has a function of physically deleting a data record in the file 2 indicated by the position information when the position information is passed from the application program 3.

The data record search means 13 includes a key unit 1
7. It has a function of searching the file 2 using the value set in the suffix part 18 as a search key value.

The suffix management means 14 has a function of setting an initial value of the suffix 23 in the suffix part 18,
When storing data records, the data record storage means 15
Suffix 2 of the data record to be stored this time
3. A function of notifying a value to be set in the current suffix 24. When storing a data record, the key value which is the data record which has been logically deleted and which the application program 3 is aware of in the data record is stored this time. It has a function to change the value of the suffix 23 for the same data record as the key value that the application program 3 of the data record to be intended is aware of.

When storing the data record, the data record storage means 15 adds the items of the suffix 23 and the current suffix 24 to the data record requested to be stored by the application program 3, and adds the suffix to the added suffix 23 and the current suffix 24. It has a function of setting a value passed from the management unit 14 and storing the value in the file 2.

FIG. 2 is a flowchart showing a processing example of the data record logical deletion means 11, FIG. 3 is a flowchart showing a processing example of the data record physical deletion means 12, and FIGS. FIG. 6 is a flowchart showing a processing example of the data record storage means 15, and FIG. 7 is a flowchart showing a processing example of the suffix management means 14.
Hereinafter, the operation of this embodiment will be described with reference to the drawings.

First, the operation for storing a data record in the file 2 will be described.

When storing a data record in the file 2, the application program 3 passes the data record to be stored to the data record storage unit 15. The data record passed by the application program 3 to the data record storage means 15 has identification information, a key, and data, as shown in FIG. Here, the identification information corresponds to the identification information 21 of the data record stored in the file 2, the key corresponds to the primary key 22, and the data corresponds to the data 25.

When the data record is passed from the application program 3, the data record storage means 15 sets the key value (ABC) set in the data record passed from the application program 3 as shown in the flowchart of FIG. ) Is passed to the suffix management means 14 (step S51).

When the key value "ABC" is passed from the data record storage means 15, the suffix management means 14
As shown in the flowchart of FIG. 7, the file 2 is searched and “ABC” is set in the primary key 22 and the suffix 23
A data record in which the initial value ("0000" in this embodiment) is set is searched for (step S6).
1).

If the suffix cannot be found (NO in step S62), the initial value of the suffix is "0000".
And the initial value of the current suffix (in this embodiment, “0”
000 ") are passed to the data record storage means 15 as values to be set in the suffix 23 and the current suffix 24 of the data record to be stored this time (step S63).

If the data record is found (YES in step S62), it is determined whether the found data record has been logically deleted based on the logical deletion information in the identification information 21 (step S64).

When it is determined that the data has not been deleted
(No in step S64), an error notification is sent to the data record storage means 15 (step S67).
If it is determined that the logical deletion has been completed (YES in step S64), the initial value of the suffix “0000” and the value obtained by adding +1 to the value set in the current suffix 24 of the found data record are stored this time. The data record suffix 23 and the current suffix 24 are passed to the data record storage unit 15 as values to be set in the data record storage unit 15 (step S65).
A value obtained by adding +1 to the value set in the current suffix of the data record is set as the suffix in the data record found in step 1 (step S66).

The data record storage means 15 receives an error notification from the suffix management means 14 (FIG. 6,
If step S52 is YES), an error notification is sent to application program 3 (step S5).
5).

When the values set in the suffix 23 and the current suffix 24 are passed from the suffix management means 14 (NO in step S52), the data record storage means 15 stores the suffix 23 in the data record requested to be stored. , Current suffix 24, and the value passed from the suffix management unit 14 is set to the added suffix 23 and current suffix 24 (step S53). After that, the data record storage unit 15 stores the data record in which the values are set in the suffix 23 and the current suffix 24 in the file 2 (step S54).

Therefore, if the data record whose primary key 22 is "ABC" is not stored in the file 2, for example, the application program 3 sets the key value "A
BC ”data record stored in the data record storage unit 15.
9, the data record L1 with the primary key = ABC, the suffix = 0000, and the current suffix = 0000 is stored in the file 2 as shown in FIG.

Next, the operation for logically deleting the data record stored in the file 2 will be described.

When logically deleting a data record stored in the file 2, the application program 3 first stores information requesting logical deletion in the instruction identification information section 16 and stores data to be logically deleted in the key section 17. The key value (corresponding to the primary key 22 of the data record stored in the file 2) that the application program 3 of the record is aware of is stored, and then the data record search means 13 is started.

When activated, the data record search means 13 requests the suffix management means 14 to set the suffix initial value "0000" in the suffix part 18, as shown in the flowchart of FIG. Step S21). As a result, the suffix management unit 14
Initial value of suffix "0000" is suffix part 1
Set to 8.

Next, the data record search means 13
Referring to the instruction identification information section 16, whether logical deletion has been requested, whether physical deletion has been requested, whether a search for a data record that has not been logically deleted is requested, or whether logical deletion has been completed. It is determined whether a search for a data record as a search target is requested (steps S22 and S27 in FIG. 4 and step S37 in FIG. 5).

At this time, since information for requesting logical deletion is stored in the instruction identification information section 16, step S22 is performed.
Is YES, the data record search means 1
3 performs the process of step S23.

In step S23, the data record search means 13 searches the file 2 using the values set in the key portion 17 and the suffix portion 18 as search keys.

When the data record can be searched
(YES in step S24) notifies the application program 3 of the position information of the searched data record (step S25). Also, if the search failed
(Step S24 is NO) If an error is notified to the application program 3 (step S26).

When the position information of the data record is notified from the data record search means 13, the application program 3 sends the data record logical deletion means 11,
Notifying the data record physical deletion means 12 of the position information,
When an error notification is received, an error display or the like is performed.

When the position information is passed from the application program 3, the data record logical deletion means 11 and the data record physical deletion means 12
The processing shown in the flowchart of FIG.

The data record logical deletion means 11 is the same as that shown in FIG.
As shown in (1), when the position information is passed from the application program 3, it is determined whether or not a logical deletion is requested by referring to the instruction identification information section 16 (step S5).
1) If it is determined that the logical deletion is requested (step S1 is YES), the application program 3
The logical deletion information included in the identification information of the data record indicated by the position information passed from
E "and logically delete the data record. Also, if it is determined that logical deletion has not been requested
(No in step S1), the process ends.

On the other hand, the data record physical deletion means 12
When the position information is passed from the application program 3, as shown in the flow chart of FIG.
6 to determine whether physical deletion has been requested.
(Step S11) If it is determined that the physical deletion is requested (Step S11 is YES), the data record indicated by the position information notified from the application program 3 is physically deleted from the file 2. Also, when it is determined that physical deletion has not been instructed
If (step S11 is NO), the process ends.

At this time, since the information for requesting the logical deletion is stored in the instruction identification information section 16, the data record logical deleting means 11
The logical deletion information included in the identification information in the data record indicated by the position information passed from the server is changed to “DELETE”.

Therefore, now, for example, as shown in FIG.
Data record L1 not logically deleted in file 2
Is stored in the application program 3
Tries to logically delete this data record L1,
It is assumed that information for requesting logical deletion is set in the instruction identification information section 16, the key value “ABC” of the data record L 1, which is conscious of the application program 3, is set in the key section 17, and the data record search means 13 is started. Then
The following processing will be performed.

When started from the application program 3, the data record search means 13 requests the suffix management means 14 to set the initial value of the suffix in the suffix part 18 (FIG. 4, step S).
21), the suffix management means 14 sets the initial value “000”
When "0" is set in the suffix part 18, the key part 17,
The key value “ABC0” set in the suffix part 18
The file 2 is searched using “000” as a search key (step S23). Thereby, the data record search means 1
3 finds a data record L1 in which "ABC" is set in the primary key 22 and "0000" is set in the suffix 23, and notifies the application program 3 of the position information (steps S24 and S25).

When the application program 3 is notified of the position information of the data record L1, the data record logical deleting means 11 and the data record physical deleting means 12
Pass the location information to.

As a result, the data record logical deletion means 11 changes the logical deletion information in the identification information 21 of the data record L1 indicated by the position information passed from the application program 3 to "DELETE" (FIG. 2, step S2). As a result, the data record L
1 is as shown in FIG. The hatched lines indicate that the data record has been logically deleted.

FIG. 11 shows that when the content of the file 2 is as shown in FIG.
Request storage of a data record whose key value is "ABC",
FIG. 9 is a diagram showing the contents of file 2 when data record L2 is stored in accordance with this request.

That is, when the storage of the data record whose key value is “ABC” is requested, the data record storage means 15
Passes the key value “ABC” to the suffix management means 14 (FIG. 6, step S51), and
4 is the primary key 22 = ABC, suffix 23 = 000
A logically deleted data record L1 of 0 is searched for (FIG. 7, steps S61, S62, S64). Thereafter, the suffix management unit 14 sets the initial value “0
000 ”and the value“ 0000 ”set in the current suffix 24 of the found data record L1 by +
The data record storage means 15 stores the value "0001" which is set to "1".
To the primary key 22 = ABC, suffix 23 = 00
00, the data record L2 having the current suffix 24 = 0001 is stored in the file (step S6 in FIG. 7).
5, steps S53 and S54 in FIG. 6), and further, “000” is added to the suffix 23 in the found data record L1.
"1" is set (FIG. 7, step S66). Therefore, the contents of the file 2 are as shown in FIG.

FIG. 12 shows that when the contents of the file 2 are as shown in FIG. 11, the application program 3 requests the logical deletion of the data record whose key value is "ABC", and the logical deletion of the data record is performed according to the request. FIG. 7 is a diagram showing the contents of file 2 when the above-mentioned is performed.

That is, when a logical deletion of a data record whose key value is “ABC” is requested, the data record search means 13 sets the primary key 22 = ABC and the suffix 23 = 00.
00 is searched for the data record L2.
The second position information is notified to the application program 3 (FIG. 4, steps S21 to S25). Thereafter, the application program 3 passes the position information of the data record L2 to the data record logical deletion unit 11, and the data record logical deletion unit 11 changes the logical deletion information in the data record L2 indicated by the position information to “DELETE”.
(Steps S1 and S2 in FIG. 2). Therefore, the contents of the file 2 are as shown in FIG.

FIG. 13 shows that when the content of the file 2 is as shown in FIG.
Request storage of a data record whose key value is "ABC",
FIG. 9 is a diagram showing the contents of file 2 when data record L3 is stored in accordance with this request.

That is, when storage of a data record whose key value is “ABC” is requested, the data record storage means 15
Passes the key value “ABC” to the suffix management means 14 (FIG. 6, step S51),
But primary key 22 = ABC, suffix 23 = 0000
Of the logically deleted data record L2 (FIG. 7)
Steps S61, S62, S64). Thereafter, the suffix management unit 14 sets the initial value of the suffix “000”.
"0" and the value "0002" obtained by adding +1 to the value "0001" set in the current suffix 24 of the found data record L2 to the data record storage means 15, and the primary key 22 = ABC and the suffix 23 = 000.
0, the data record L3 having the current suffix 24 = 0002 is stored in the file 2 (step S6 in FIG. 7).
5, steps S53 and S54 in FIG. 6, and further, “000” is added to the suffix 23 in the found data record L2.
2 is set (FIG. 7, step S66). Accordingly, the contents of the file 2 are as shown in FIG.

Next, a description will be given of an operation in a case where a search is performed with a data record that has not been logically deleted as a search target.

When the application program 3 requests a search for a data record that has not been logically deleted, it requests the instruction identification information section 16 to execute a search for a data record that has not been logically deleted. In addition to setting the information, the key unit 17 sets a key value (for example, “ABC”) conscious of the application program 3 of the data record to be searched, and then starts the data record search unit 13. .

When activated, the data record search means 13 requests the suffix management means 14 to set the initial value of the suffix in the suffix part 18 (FIG. 4, step S21). Thereby, the suffix management unit 14 sets the initial value of the suffix “0000” in the suffix part 18.

Thereafter, the data record search means 13
Since information for requesting execution of a search for a data record that has not been logically deleted is set in the instruction identification information section 16 (FIG. 5, step S37 is YES), the information is set in the key section 17 and the suffix section 18. The file 2 is searched using the entered key value "ABC0000" as a search key (step S38).

If the search is not successful (NO in step S39), the application program 3 is notified that there is no corresponding data record (step S4).
2). If the search is successful (step S39 is YE
S) determines whether or not the retrieved data record is a logically deleted data record based on the logical deletion information (step S40).

When it is determined that the data record is a logically deleted data record (YES in step S40), the application program 3 is notified that there is no corresponding data record (step S42). If determined, the search result is notified to the application program 3 (step S41).

Now, for example, when the contents of the file 2 are as shown in FIG.
Sets information for requesting execution of a search for a data record that has not been logically deleted in the instruction identification information section 16, sets a key value “ABC” in the key section 17, and then sets the data record search means. If you start 13
The following processing is performed.

When activated, the data record search means 13 requests to set the initial value of the suffix in the suffix part 18 (FIG. 4, step S21).
8 is set to the initial value of the suffix “0000”.

Thereafter, the data record search means 13
Since information for requesting the execution of a search for a data record that has not been logically deleted is set in the instruction identification information section 16 (FIG. 5, step S37 is YES), the information is set in the key section 17 and the suffix section 18. The file 2 is searched using the entered key value “ABC0000” as a search key (step S38). By this search, the primary key 22
= ABC, suffix 23 = 0000 and the logically undeleted data record L3 is found.

When finding the data record L3 that has not been logically deleted, the data record search means 13 notifies the contents of the data record L3 to the application program 3 (steps S39 to S41).

Next, a description will be given of the operation in the case where a search is performed with the data record having been logically deleted as a search target.

When the application program 3 performs a search using a data record whose logic has been deleted as a search target, the application program 3 sets in the instruction identification information section 16 information for requesting execution of a search with the data record whose logic has been deleted as a search target. At the same time, a key value (for example, “ABC”) conscious of the application program 3 of the data record to be searched is set in the key unit 17, and thereafter,
The data record search means 13 is started.

When activated, the data record search means 13 requests the suffix management means 14 to set the initial value of the suffix in the suffix part 18 (FIG. 4, step S21). Thereby, the suffix management unit 14 sets the initial value of the suffix “0000” in the suffix part 18.

Thereafter, the data record search means 13
Since the information for requesting the execution of the search for the data record whose logical deletion has been made is set in the instruction identification information section 16 (FIG. 5, step S37 is NO), the key section 1 is set.
7. The key value “AB” set in the suffix
Search for file 2 using "C0000" as a search key
(Step S43).

If the search is not successful (NO in step S44), the application program 3 is notified that there is no corresponding data record (step S4).
2). If the search is successful (step S44 is YE
S) determines whether or not the retrieved data record is a logically deleted data record based on the logical deletion information (step S45).

If it is determined that the data record is not a logically deleted data record (NO in step S45), the primary key 22 is the key value set in the key unit 17, and the suffix 23 is the data record of the data record searched this time. The data record of the value set in the current suffix 24 is searched (step S47). If it is determined that the data record has been subjected to the logical search (step S4
5 is YES), after notifying the search result to the application program 3 (step S46), and then step S47.
Is performed.

If the data record can be searched in step S47 and the data record is an unsearched data record (steps S48 and S49 are YES and NO, respectively), the process returns to step S46. (NO in step S48, step S49
Is YES), the application program 3 is notified of the end of the search (step S50), and the process is terminated.

Now, for example, when the contents of the file 2 are as shown in FIG.
Sets the information requesting that the search target be a logically deleted data record in the instruction identification information section 16, sets the key value "ABC" in the key section 17, and then activates the data record search means 13. If so, the following processing is performed.

When activated, the data record search means 13 requests that the initial value of the suffix be set in the suffix part 18 (step S21 in FIG. 4).
8 is set to the initial value of the suffix “0000”.

Thereafter, the data record search means 13
Since the information for requesting the execution of the search for the data record whose logic has been deleted is set in the instruction identification information section 16 (FIG. 5, step S37 is NO), the key section 1 is set.
7. The key value “AB” set in the suffix
The file 2 is searched using "C0000" as a search key (step S43). By this search, primary key 22 = A
Data record L with BC, suffix 23 = 0000
3 is found.

Since the data record L3 is a data record that has not been logically deleted (N in step S45)
O), the suffix management means 14 determines that the primary key 22 is the value set in the key portion 17 and the suffix 23 is the data record of the value “0002” set in the current suffix 24 of the data record L3 searched this time. Is retrieved (step S47).

By this search, an unsearched data record L2 is found (steps S48 and S49 are Y
(ES, NO), the suffix management means 14 notifies the contents of the data record L2 to the application program 3 (step S46).

Thereafter, the suffix management means 14 determines that the key value set in the key section 17 is "ABC" and the current suffix 24 of the data record L2 searched this time.
Is set to “0001”, “ABC” is set in the primary key 22 and the suffix 2
A data record in which "0001" is set to 3 is searched (step S47).

As a result of this search, an unsearched data record L1 is searched (steps S48 and S49 are YE
(S, NO), the suffix management unit 14 notifies the application program 3 of the contents of the data record.
(Step S46).

Thereafter, the suffix management means 14 determines that the key value set in the key section 17 is “ABC” and the current suffix 24 of the data record L1 searched this time.
Is set to “0000”, “ABC” is set in the primary key 22 and the suffix 2
A data record in which “0000” is set in 3 is searched (step S47).

By this search, the data record L3 is searched. Since the data record L3 is a searched data record (YES in step S49), the suffix management unit 14 notifies the application program 3 of the end of the search. Later (step S50), the process ends.

Next, the operation for physically deleting a data record from the file 2 will be described.

When physically deleting a data record from the file 2, the application program 3 first stores the information for requesting physical deletion and the deletion reference time in the instruction identification information section 16, and stores the physical deletion in the key section 17. A key value (for example, “ABC”) that the application program 3 of the data record is aware of is set, and then the data record search unit 13 is started.

When activated, the data record search means 13 requests the suffix management means 14 to set the initial value of the suffix in the suffix part 18 as shown in the flow chart of FIG. 4 (step S21). Accordingly, the suffix management unit 14 sets the initial value “0000” of the suffix in the suffix part 18.

Thereafter, the data record search means 13
Since information for requesting physical deletion is set in the instruction identification information section 16 (YES in step S27), the key value “A” set in the key section 17 and the suffix section 18 is set.
Search for file 2 using "BC0000" as a search key
(Step S28).

If the data record with the key value "ABC0000" cannot be retrieved, an error notification is sent to the application program 3 (step S3).
0) If it is found, it is determined whether or not the storage time of the found data record is before the deletion reference time stored in the instruction identification information section 16 (step S31).

If it is determined that the storage time is before the deletion reference time (step S31 is YES), the application program 3 is notified of the location information of the searched data record (step S32), and then the value of the primary key is determined. Is a key value set in the key portion 17 and a data record having a key value set in the current suffix 24 of the data record whose suffix 23 is currently searched (step S33), and the storage time is deleted. When it is determined that it is after the reference time (step S31 is N
O) performs the process of step S33.

If the data record cannot be retrieved in step S33 (NO in step S34), the data record retrieval means 13 notifies the application program 3 of the termination of the retrieval (step S36), and terminates the processing. , If the search is successful (step S34 is YE
S) determines whether or not the searched data record is a searched data record (step S35).

If it is determined that the data record has been searched (step S35: YES), the end of the search is notified to the application program 3 (step S36). If it is determined that it is not (NO in step S35)
Performs the process of step S31.

Now, for example, when the contents of the file 2 are as shown in FIG.
However, when the value of the primary key 22 is “ABC” and the storage time is to physically delete the data record before the deletion reference time α, the information for instructing physical deletion and the deletion reference time α are stored in the instruction identification information section 16. At the same time, if the key value “ABC” is stored in the key unit 17 and the data record search unit 13 is subsequently activated, the following processing is performed. However, the data records L1 to L shown in FIG.
3, it is assumed that only the storage time of the data record L1 is before the reference time α.

When the data record search means 13 is activated, the primary key 22 = ABC and the suffix 23 = 000
0 data record L3, and the data record L
It is determined whether or not the storage time of No. 3 is before the deletion reference time α (steps S27 to S31). Data record L3
Is stored after the deletion reference time α, the data record search means 13 searches for a data record in which “ABC” is set in the primary key 22 and “0002” is set in the suffix 23 (step S33). ).

As a result of this search, a data record L2 that has not been searched is found (steps S34 and S3).
5 is YES, NO), the data record search means 13
It is determined whether the storage time of the data record L2 is before the deletion reference time α (step S31).

The data record L2 is stored after the deletion reference time α.
Searches for a data record in which "ABC" is set in the primary key 22 and "0001" is set in the suffix 23 (step S33).

As a result of this search, a data record L1 that has not been searched is found, so the data record search means 13 determines whether or not the storage time of the data record L1 is before the deletion reference time α (step S31). .

The data record L1 is stored before the deletion reference time α (YES in step S31).
The data record search means 13 notifies the application program 3 of the position information of the data record L1.
(Step S32). Thereafter, the data record search means 13 searches for a data record in which "ABC" is set in the primary key 22 and "0000" is set in the suffix 23, thereby searching for the data record L3 (step S33). Since the data record L3 is a searched data record (YES in step S35), after notifying the application program 3 of the end of the search (step S36), the processing ends.

When the application program 3 receives the position information of the data record L1 from the data record search unit 13, it sends it to the data record physical deletion unit 1.
Hand over to 2.

When the position information of the data record L1 is passed, the data record physical deletion means 12 physically deletes the data record L1 from the file 2 according to the position information. As a result, as shown in FIG. 14, the contents of file 2 are data records L1 out of data records L1 to L3.
1 is physically deleted.

[0105]

As described above, according to the present invention, a key item of a data record stored in a file is defined as a primary key corresponding to a key that the application program is aware of,
A primary key value is composed of a suffix for making the key value of the same data record unique, and a current suffix is provided in the data record indicating a storage order of the data records having the same primary key, If a data record is requested to be stored from the application program, if a logically deleted data record with the same key value and primary key value as the application program's conscious of the requested data record exists in the file The suffix value of the logically deleted data record is changed based on the current suffix value of the data record, and the application program is aware of the primary key, suffix, and current suffix value of the data record requested to be stored. Key value, The initial value of the fix, the value of the suffix after the change of the logically deleted data record is stored in the file, and the key value and primary key of the data record to be newly stored are aware of the application program. Even when a data record having the same value exists in the file, it is not necessary to physically delete the logically deleted data record, so that the processing speed can be improved and the production time during program development can be improved. There is an effect that the property can be increased.

Further, the present invention comprises a primary key and a suffix, wherein the primary key is set to a key value specified by the application program. Since it is possible to search for data records that have been logically deleted, there is an effect that it is possible to reuse data records that have been logically deleted.

Further, since the present invention includes a data record physical deletion means for physically deleting a data record from a file, an unnecessary data record can be deleted when the file capacity is insufficient.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing example of a data record logical deletion unit 11;

FIG. 3 is a flowchart showing a processing example of a data record physical deletion unit 12;

FIG. 4 is a flowchart showing a processing example of a data record search means 13;

FIG. 5 is a flowchart showing a processing example of a data record search means 13;

FIG. 6 is a flowchart showing a processing example of a data record storage means 15;

FIG. 7 is a flowchart showing a processing example of a suffix management unit 14;

FIG. 8 is a diagram showing a format of a data record that is aware of the application program 3.

FIG. 9 is a diagram showing a state of file 2 when a data record is stored.

FIG. 10 is a diagram showing a state of file 2 when a data record is logically deleted.

FIG. 11 shows a file 2 when data records are stored.
It is a figure showing the state of.

FIG. 12 is a diagram showing a state of file 2 when a data record is logically deleted.

FIG. 13 shows a file 2 when data records are stored.
It is a figure showing the state of.

FIG. 14 is a diagram showing a state of a file when a data record is physically deleted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... File management system 11 ... Data record logical deletion means 12 ... Data record physical deletion means 13 ... Data record search means 14 ... Suffix management means 15 ... Data record storage means 16 ... Instruction identification information part 17 ... Key part 18 ... Suffix part 2 ... file 3 ... application program

Claims (3)

(57) [Claims] In a file management system that does not allow duplication of key values of data records in a file, the data record includes a primary key whose key item corresponds to a key that the application program is aware of, and a primary key. And a suffix to make the key value of the same data record unique.
The file management system includes a current suffix indicating a storage order in the same data record whose primary key is the same and logical deletion information indicating whether or not logical deletion has been completed. In response to the delete request, of the data records stored in the file, the key value specified by the application program is set in the primary key and the logical value of the data record whose initial value is set in the suffix is set. A data record logical deletion unit for logically deleting the deletion information; and a key value that the application program is aware of as a key value of the data record in a primary key in response to a data record storage request from the application program. Is set, and the initial value is set in the suffix. If the logically deleted data record exists in the file, the suffix of the data record is changed based on the value set in the current suffix of the data record, and the suffix after the change is changed. Is output, and if it does not exist,
A suffix management means for outputting an initial value of the current suffix; and a value output from the suffix management means, so that the data record requested by the application program to be stored is converted into a primary key, a suffix, and a value of the current suffix. Data record storage means for storing in the file a data record of a key value, a current suffix initial value, and a value output by the suffix management means, which are conscious of the application program; and data not logically deleted from the application program. When a search request specifying a key value for a record to be searched is output, a search key is used with the primary key value as the key value specified by the application program and the suffix value as the initial value. A data record for searching the file for a data record that has not been logically deleted, in which the key value specified by the application program is set as the primary key and the initial value is set as the suffix from the file. A logical deletion data management method comprising a search means. 2. The data record search means outputs a search request that specifies a key value from the application program as a search target for a logically deleted data record. A logic in which a value of a suffix in a search key whose value is a key value specified by the application program is changed to search the file, and a key value specified by the application program is set as a primary key from the file. 2. The logically deleted data management method according to claim 1, wherein a deleted data record is searched. 3. A data record physical deletion means for physically deleting a data record requested to be physically deleted from the file in response to a physical deletion request from the application program. Logical deletion data management method described.