JP2002032248A - Providing system of version of transaction in data base inquiry processing and data base inquiry processing system using version provided by the same system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a providing system of a version of transaction in an inquiry processing the mounting of which is simplified and which is easily maintained. SOLUTION: A proper version is provided to the transaction by which inquiry is carried out by storing a last updated transaction ID 52 as a transaction ID of the transaction by which a record is updated last and a field 54 before update as data of a data base before update in addition to a filed 53 as record data and a record ID 51 to uniquely identify it a field 54 before update as data of a data base before update in the record of a data base file.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for providing a version of a transaction in database query processing and a database query processing system. More specifically, the present invention relates to a conventional database file access means. A system for providing a version of a transaction in a database query process, in which version provision and checking of integrity constraints can be omitted, implementation is simplified, and maintenance is easy, and database query processing using the version provided by the system About the system.

[0002]

2. Description of the Related Art When a plurality of transactions operate on a certain database, the transaction has an isolation property by its nature.
The same database looks different for each transaction.

FIGS. 5 to 7 are diagrams for explaining the difference in the appearance of a database from each transaction.
It is a figure for explaining the difference taking the database which manages the balance of a bank as an example. Now, the database contains A,
The deposit balances of three persons B and C are recorded, and are assumed to be $ 100, $ 500, and $ 300, respectively. V0 in FIG.
Represents this database when there are no operating transactions. Assume that two transactions T1, T2 have begun and each has begun operating on this database. The transaction T1 corrects the balance of Mr. A to $ 200, and refers to the balance of Mr. C. Transaction T2 corrects the balance of Mr. B to $ 0 and refers to the balance of Mr. C. At this time, for transaction T1, the balances of A and C are each $ 2.
00, $ 300, for transaction T2,
B and C's balance looks $ 0 and $ 300, respectively.

The appearance and appearance of the database for each transaction will be referred to as a version. In FIG. 5, V1 is the version for transaction T1, and V2 is the version for transaction T2.

When a transaction commits and ends, the portion of the version of the transaction that has changed since the transaction started is reflected in the actual database. When a transaction aborts and ends, the changed portion of the transaction version is discarded and the actual database remains unchanged. For example, when the transaction T1 in FIG. 5 commits and ends, the change in the balance of Mr. A from $ 100 to $ 200 in the transaction T1 is reflected in the actual database as in V0 'in FIG. Transactional updates must not result in inconsistencies between transactional versions.

In V1 of FIG. 5, the balance of Mr. A has been changed from $ 100 to $ 200 by transaction T1, so
Looks 200. However, transaction T1
Isn't finished yet, so I don't know if this change will be reflected in the actual database. Therefore, at this time, if transaction T2 refers to Mr. A's balance, V2
Even if the balance of Mr. A in V0 or V1 is visible, inconsistency may occur. As shown in FIG. 7A, when $ 100, which is the balance of Mr. A in V0, is the balance of Mr. A in V2, when the transaction T1 commits,
The balance of Mr. A is different between 0 'and V2.
Further, even if $ 200 of V1 is set to the balance at V2 as shown in FIG. 7B, when transaction T1 aborts, the balance of Mr. A differs between V0 and V2.

[0007] In order to prevent such an inconsistency between versions for each transaction and to protect the isolation of transactions, conventionally, two-phase locking is used.
Or timestamp ordering (timestamp
There is known a serialization technique for transactions such as ordering.

However, in spite of the possibility that such inconsistency may arise, it is sometimes useful to be able to refer to other transaction versions. For example, when the total deposit balance managed by the bank must be equal to or more than $ 800, in the situation of FIG. 5, V0 is $ 100 + $ 500 + $ 3.
00 = $ 900, which satisfies this condition. T1
Tries to correct Mr. A's balance to $ 200,
To check whether this condition is satisfied, the balance of Mr. B is required. Mr. B's balance has been modified to $ 0 by transaction T2, but since transaction T2 has not been completed, this modification has not been finalized. In such a case, it is checked whether the condition is satisfied using each of Mr. B's balances of V0 and V2, and if both are satisfied, the condition is satisfied even if the transaction T2 commits or aborts. Become. In the balance of Mr. B in V0, the condition is satisfied with $ 200 + $ 500 + $ 300 = $ 1000, but in the balance of Mr. B in V2, {200+}
Since the condition 0 + $ 300 = $ 500 does not satisfy the condition, T1
Cannot correct Mr. A's balance.

A condition set in such a database is called an integrity constraint, and a transaction satisfies the condition by executing the condition.
It is necessary to maintain the consistency of the database. Integrity constraints also include other uniqueness (uni)
There are que constraints and primary key constraints, etc., and the transaction must make sure that the changes satisfy these constraints before changing the database. To do so, as in the previous example,
It must be possible to refer to all other transaction versions as needed.

Also, an isolation level defined by the SQL standard.
In some cases, a version of another transaction can be referred to by partially giving up its isolation from the beginning of the transaction.

A software configuration of a conventional transaction processing system for realizing such a transaction version will be described. FIG. 8 is a diagram illustrating an example of a software configuration of a transaction processing system according to the related art. The requested inquiry is accepted by the inquiry input / output means 62. The query input / output unit 62 passes the received query to the query optimization unit 63, and asks the query optimization unit 63 to determine how to execute the query, that is, determine an access plan. The determined access plan is passed to the query execution means 64, and the query is actually executed. The query execution means 64 is provided with the transaction control means 6 if necessary.
7 is instructed to operate a transaction, and the database file access means 65 is instructed to operate a database file.

Database file access means 65
Operates the database file 68 on the hard disk in which the record, which is the data of the database, is recorded in accordance with the instruction from the query execution means 64. At this time, in order to isolate the database file 68 operated by a certain transaction, its record, and the like from other transactions, and to generate a version of the transaction, a transaction simultaneous execution control unit 66 such as a lock based on a two-phase rule is called. Whether the state after the operation satisfies the defined integrity constraint is checked by referring to the record before update and the record after update, which is a version of another transaction, according to the contents of the constraint. Depending on the structure of the database file 68 and the failure recovery method to be used, there is a method in which records after updating are obtained from the database file 68 and records before updating are obtained from the log file 69. Log file 69
The information required for recovery from a failure is recorded on a hard disk.

The transaction control means 67 starts and ends a transaction and executes the transaction simultaneous execution control means 6 in accordance with an instruction from the query execution means 64.
6 to change the isolation level of the transaction.

[0014]

However, the database file access means described above provides operation means according to the type of database file, such as a record file for storing records and a B + tree file for providing an index. The implementation is complicated and difficult to maintain.

In the database file access means described above, (1) providing a version of a transaction by calling the transaction concurrent execution control means, and (2) the database after operation satisfies the integrity constraint defined in the database. Inspecting,
(3) Referencing the version of another transaction from the database file and log file for this check, that is, the record before and after the update, makes it more difficult to provide operating means for the database file.

Further, when the access plan is generated by the query optimizing means, the provision of the transaction version and the check of the integrity constraint are postponed, or even if it is found that the transaction plan is not necessary at all, when the database file is operated,
These operations are always performed inside the database file access means.

The present invention has been made in view of the above circumstances, and provides a transaction version by calling the transaction concurrent execution control means in the conventional database file access means and omits checking consistency constraints. It is an object of the present invention to provide a system for providing a version of a transaction in a database query process and a database query processing system which are simplified in implementation and easy to maintain.

[0018]

According to a first aspect of the present invention, when a plurality of transaction processes are performed on the database in the process of query processing in response to a query request to the database, a record of a file of the database is stored in the database. By storing, in addition to the record data, the ID of the transaction that updated the record and the record data before the update as field values,
It is characterized by providing an appropriate version for the transaction executing the query.

According to a second aspect of the present invention, a desired level of isolation in a transaction is realized by using a version provided by the method for providing a version of a transaction in the database query processing according to the first aspect of the present invention. Is performed.

According to a third aspect of the present invention, a consistency check of a database is performed by using a version provided by the method for providing a version of a transaction in the database query processing according to the first aspect of the present invention, and according to the result of the check. It is characterized by performing a query process of a database.

According to a fourth aspect of the present invention, when a plurality of transaction processes are performed on the database in the process of query processing in response to a query request to the database, a record of the database file is added to the record data in addition to the record data. By storing the ID of the transaction that updated the record and the record data before the update as field values, an appropriate version is provided for the transaction that is executing the inquiry.

According to a fifth aspect of the present invention, there is provided a database query processing in which a desired isolation level in a transaction is realized by using a version provided by the transaction version providing system in the database query processing of the fourth aspect of the present invention. Is performed.

According to a sixth aspect of the present invention, a consistency check of a database is performed by using a version provided by a system for providing a version of a transaction in a database query process according to the fourth aspect of the present invention. It is characterized by performing a query process of a database.

According to a seventh aspect of the present invention, there is provided a transaction version comprising a server having a database file, a client terminal for making an inquiry request to the database, and a network connecting the server and the client terminal. In the apparatus, when performing a plurality of transaction processes on the database in the course of an inquiry process in response to an inquiry request to the database from the client terminal, in addition to record data in a record of a file of the database, By storing the ID of the transaction that has updated the record and the record data before the update as field values, an appropriate version is provided for the transaction that is executing the query. .

According to an eighth aspect of the present invention, there is provided a database query processing which realizes a desired isolation level in a transaction by using the version provided by the transaction version providing apparatus in the database query processing according to the seventh aspect of the present invention. Is performed.

According to a ninth aspect of the present invention, a consistency check of a database is performed by using a version provided by a transaction version providing device in a database query process according to the seventh aspect of the present invention, and according to the check result. It is characterized by performing a query process of a database.

According to a tenth aspect of the present invention, when a plurality of transaction processes are performed on the database in the process of query processing in response to a query request to the database, a record of the database file is added to the record data in addition to the record data. By storing the ID of the transaction that updated the record and the record data before the update as field values, an appropriate version is provided for the transaction that is executing the inquiry.

According to an eleventh aspect of the present invention, a desired isolation in a transaction is obtained by using a version provided by executing a program for executing a version of a transaction in the database query processing according to the tenth aspect of the present invention. It is characterized in that the level is realized and the query processing of the database is performed.

According to a twelfth aspect of the present invention, a version provided by executing a program for providing a version of a transaction in the database query processing according to the tenth aspect of the present invention is used to execute a database integrity constraint. A check is performed, and an inquiry process of a database is performed according to the check result.

[0030]

FIG. 1 is a diagram showing an example of a server-client system configured for transaction processing according to the present invention. FIG. 2 is an expanded view of FIG. The figure showing an example of the hardware configuration of the configured computer system,
FIG. 3 is a diagram showing an example of a functional configuration for transaction processing or a software configuration of a system according to the present invention. 1 and 2, 1 is a memory 11, a CPU 1
2, a server having a hard disk 13, 2 a network such as a communication network, and 3 (3 ') a memory 31
(31 '), CPU 32 (32'), hard disk 3
3 (33 '), a plurality of terminals (also called clients or client terminals) connected to the server 1 via the communication network 2, and 34 (34')
A monitor which is a display device of (3 '); a mouse which is a pointing device of terminal 3 (3');
A keyboard 36 (36 ') is an input device of the terminal 3 (3').

The terminal 3 (3 ') is a computer used by a user of the system to input an inquiry request and output an inquiry result. Generally, the terminal 3 is provided with a pointing device such as a keyboard 36 and a mouse 35 for inputting an inquiry request and a display 34 for displaying an inquiry result. The terminal 3 includes a memory 31, a CPU 32, and a hard disk 33,
A software program can be executed. In the terminal 3, an inquiry input / output unit 43 in FIG. 3 described later is executed as a program.

The server 1 is a computer for performing an inquiry process according to the inquiry request input from the terminal 3 and returning the result to the terminal 3. The terminal 3 and the server 1 are connected by a network 2 described later. The server 1 has a memory 11,
It has a CPU 12 and a hard disk 13 and can execute a program by software. In the server 1, a query optimizing unit 43, a query executing unit 44, a database file access unit 45, a transaction simultaneous execution control unit 46, a transaction control unit 47, and a deleted record discarding query issuing unit 41 in FIG.
Is executed as a program. The database file 48 is recorded on the hard disk 13.

The network 2 is a transmission line connecting the terminal 3 and the server 1. Generally, it is realized by a cable, and TCP / IP is used as a communication protocol. However, if the communication protocol between the terminal 3 and the server 1 matches, a wireless LAN without using a cable or a network using broadcast waves may be used.

With reference to FIG. 3, the outline of the provision of the transaction version and the inquiry processing according to the present invention will be functionally described. As means for realizing the functions of version provision and query processing according to the present invention, a deleted record discarding query issuing means 41 and a query input / output means 42, a query optimization It has means 43, query execution means 44, database file access means 45, transaction simultaneous execution control means 46, transaction control means 47, and database file 48. Each of the above means will be described below focusing on differences from each means described in FIG.

The query execution unit 44 provides a version of the transaction implemented in the conventional database file access unit 65 and checks the integrity constraint by executing an access plan. Here, the version (vers
“ion)” refers to the appearance and appearance of the database for each transaction. The query optimizing unit 43 generates an access plan including provision of a transaction version and checking of integrity constraints as necessary according to the query given from the query input / output unit 42.

In the records of the database file 48, in addition to the fields representing the data of the database,
Define the following fields: (1) A field representing the transaction ID of the transaction that last updated the record, and (2) a field representing the data of the database before the update.

The update operation of the database file 48 by the query execution means 44 includes the transaction ID of the last updated transaction of the target record,
Update the field representing the data before update, if necessary.

Of the transaction versions provided by the query execution means 44, the possible ones are the transaction ID of the currently executing transaction in the transaction table and the transaction ID of the last updated transaction in the database file record. This is performed by a selection operation using a transaction ID. For those that are not possible, this is performed by the transaction simultaneous execution control means 46 such as a lock based on the conventional two-phase rule.

The checking of the database consistency constraint by the query execution means 44 is performed using the data after the update from the database file 48 and the data before the update for the record being updated by another transaction.

According to the instruction from the query execution means 44, the transaction control means 47 (1) starts the transaction, (2) ends the transaction (commit,
Abort) and (3) changing the isolation level of the transaction. Each time a transaction is started, the transaction control means 47 assigns a transaction ID capable of uniquely identifying each transaction. The transaction ID of the transaction currently being executed, that is, the transaction that has not been completed, is managed in the transaction table on the memory 11.

FIG. 4 is a diagram showing an example of a database file and a transaction table for executing the inquiry processing according to the present invention. For example, looking at the transaction table of FIG. 4, there are two transactions currently being executed, and their transaction IDs are "11" and "1".
2 ".

The database file 48 is stored on the hard disk 13 and records data of the database as a set of records. The upper part of FIG. 4 shows a certain database file. Each row represents a record, and each record has a record ID 51 for uniquely identifying the record, a last update transaction ID 52 which is a transaction ID of a transaction which last updated the record, and a field 53 which is data of a database. , A pre-update field 54 which is data of the database before the update.

Database file access means 45
Provides means for performing reference and update operations according to the type of the database file 48. Since the version is not provided by calling the transaction simultaneous execution control means 46 and the consistency constraint is not checked after the update operation, the implementation is simplified and the maintenance is easy.

The query execution unit 44 handles an update operation on the database file specified by the access plan generated by the query optimization unit 43 as follows.

(1) Inserting a record: A record ID 51 for identifying a new record, a transaction ID of a transaction to be inserted in a last update transaction ID 52, data to be inserted in a field 53, and an empty record in a field 54 before update are inserted I do. (2) Deletion of a record: The record is modified so that the field 53 of the record to be deleted becomes empty. (3) Modification of Record: The last update transaction ID 52 of the record to be modified is set to the transaction ID of the transaction to be modified, and
4 is changed to the field before correction, and the field 53 is changed to the field after correction.

For example, the record with the ID “4” in FIG. 4 is deleted by the transaction with the ID “11” because the field 53 is empty, and the record with the ID “6” is
Since both the field 53 and the pre-update field 54 are not empty, the record with the ID “11” is modified by the transaction with the ID “11”.
Since 4 is empty, it can be seen that it was inserted by the transaction whose ID is "12".

The query optimizing unit 43 generates an access plan for efficiently executing the query given from the query input / output unit 42. When the access plan is generated, if possible, an access plan that provides a version by the following set operation that retrieves a record from the database file 48 instead of providing a version of the transaction by the conventional transaction concurrent execution control means 46 is created. Generate.

(1) Referring to the version of the transaction executing the query. Last update transaction ID 5
2 is equal to the transaction ID of the currently executing transaction obtained from the transaction table other than the transaction executing the access plan,
A record whose field 53 is not empty is extracted. (2) Refer to the version of all transactions, that is, the nonrelation of the SQL-level isolation level
It is a petable read. Retrieve a record whose field 53 is not empty. (3) Refer to a special edition for checking integrity constraints.
Last updated transaction ID 52 is equal to the transaction ID of the currently executing transaction obtained from the transaction table other than the transaction executing the access plan, or field 53
Retrieves non-empty records.

Further, since these processes can be newly targeted for optimization, it is possible to generate an access plan with higher efficiency than before.

The deletion record discarding query issuing means 41
A query for actually deleting the record deleted by the committed transaction is periodically sent to the query optimizing unit 43. The query optimizing unit 43 generates an access plan in the same manner as the query from the query input / output unit 42. However, the deletion of the deleted record is performed by the query execution unit 44.
Generate an access plan so that it is not treated as a record modification by.

A method and a system for providing a version of a transaction in a database query process as one embodiment of the present invention having various functions as described above will be described.
The method and the system include, when performing a plurality of transaction processes on the database in the course of an inquiry process in response to an inquiry request to the database, in addition to record data 53 to the record of the file 48 of the database, By storing the ID 52 of the transaction that has updated the record and the record data 54 before the update as field values, a version adapted to the transaction executing the query is provided.

According to another embodiment of the present invention, a database query processing method and system realizes a desired isolation level in a transaction by using the version provided by the above-described version providing method and system. Query processing is performed.

Further, as another embodiment of the present invention,
The database query processing method and system uses the version provided by the above-described version providing method and system,
Inspection of database integrity constraints is performed, and a database inquiry process is performed according to the inspection result.

An apparatus for providing a version of a transaction in a database inquiry process according to an embodiment of the present invention includes a database file 48 (the hard disk 33).
), A client terminal 3 for making an inquiry request to the database, and a network 2 connecting the server 1 and the client terminal 3. When performing a plurality of transaction processes on the database in the course of an inquiry process in response to an inquiry request to the database from the client terminal 3, the record of the file 48 of the database includes record data 53 In addition, by storing the ID 52 of the transaction that has updated the record and the record data 54 before the update as field values, a version suitable for the transaction executing the query is provided.

According to another embodiment of the present invention, a database query processing device realizes a desired isolation level in a transaction by using a version provided by the above-described version providing device to perform a database query process. I'm trying to do it.

Further, as another embodiment of the present invention,
The database query processing device checks the consistency of the database using the version provided by the version providing device, and performs a database query process according to the check result.

Lastly, a description will be given of an embodiment of a recording medium storing a program and data for realizing functions of providing a version and inquiring processing according to the present invention. As a recording medium, specifically, a CD-ROM, a magneto-optical disk, a DV
A D-ROM, a floppy (registered trademark) disk, a flash memory, and various other ROMs and RAMs can be assumed, and a program for providing the above-described version of the present invention or realizing the inquiry processing function is recorded on these recording media. By distributing the information, the function can be easily realized. Then, the program is read by the information processing apparatus by attaching the recording medium as described above to an information processing apparatus such as a computer, or the program is stored in a storage medium provided in the information processing apparatus, and if necessary, By reading, the function of providing a version and the function of query processing according to the present invention can be executed.

The computer-readable recording medium storing the program for executing the provision of the transaction version in the database inquiry processing in this embodiment is stored in the database in the course of the inquiry processing in response to the inquiry request to the database. When a plurality of transaction processes are performed on the record, in addition to the record data 53, the ID of the transaction that updated the record is added to the record in the file 48 of the database.
2 is stored as a field value of the record data 54 before the update, and a program for providing a version adapted to the transaction executing the inquiry is recorded.

As another embodiment of the present invention, a computer-readable recording medium on which a program for executing a database inquiry process is recorded is provided by executing a program for providing a version adapted to the above transaction. A program for realizing a desired isolation level in a transaction and performing a query process on a database by using the obtained version is recorded.

Further, as another embodiment of the present invention,
A computer-readable recording medium on which a program for executing a database query process is recorded is also provided with a database provided by executing a program that provides a version adapted to the above-described transaction, and using the version provided by executing the program. The program records a program for checking constraints and performing query processing of a database according to the check results.

Actually, as described above, the memories 31, C
In the terminal 3 including the PU 32 and the hard disk 33, an inquiry input / output unit 42 for requesting an inquiry is executed as a program. In addition, the memory 11, the CPU 1
2. In the server 1 having the hard disk 13, the terminal 3
In response to an inquiry request from
3. query execution means 44, database file access means 45, transaction simultaneous execution control means 46,
The transaction control means 47 and the deletion record discard inquiry issuing means 41 are executed as programs. The database file 48 is recorded on the hard disk 13.

[0062]

According to the present invention, it is possible to provide a version of a transaction by calling the transaction concurrent execution control means in the conventional database file access means and omit checking of integrity constraints, so that the implementation is simplified. Maintenance is easy.

According to the present invention, the provision of the version of the transaction and the check of the integrity constraint in the query execution means are performed by using the field indicating the last updated transaction ID and the data before the update by using a set which has been conventionally used in the query processing. Can be processed by arithmetic.

According to the present invention, the query optimizing means can generate an access plan including provision of a version of a transaction which has not been conventionally targeted for optimization and inspection of integrity constraints, so that it is more efficient than in the past. Can execute queries.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a server-client system configured for transaction processing according to the present invention.

FIG. 2 is an expanded view of FIG. 1, showing an example of a hardware configuration of a computer system configured for transaction processing according to the present invention.

FIG. 3 is a diagram showing an example of a functional configuration for transaction processing or a software configuration of a system according to the present invention.

FIG. 4 is a diagram showing an example of a database file and a transaction table for executing an inquiry process according to the present invention.

FIG. 5 is a diagram for explaining a difference in appearance of a database from each transaction.

FIG. 6 is a diagram for explaining a difference in the appearance of a database from each transaction.

FIG. 7 is a diagram for explaining a difference in appearance of a database from each transaction.

FIG. 8 is a diagram illustrating an example of a software configuration of a transaction processing system according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Server, 2 ... Network, 3, 3 '... Client terminal, 11, 31, 31' ... Memory, 12, 32, 3
2 '... CPU, 13, 33, 33' ... hard disk,
34, 34 '... monitor, 35, 35' ... mouse, 36,
36 ': Keyboard, 41: Deleted record discarding query issuing means, 42, 62 ... Query input / output means, 43, 63 ...
Query optimizing means, 44, 64 ... Query executing means, 4
5, 65 ... database file access means, 46,
66 ... transaction simultaneous execution control means, 47, 67
... transaction control means, 48, 68 ... database file, 51 ... record ID, 52 ... last update transaction ID, 53 ... field, 54 ... field before update, 69 ... log file.

Claims (12)

[Claims] In the process of query processing in response to a query request to a database, when performing a plurality of transaction processes on the database, in addition to the record data,
A transaction version in a database query process, wherein a version adapted to the transaction executing the query is provided by storing the ID of the transaction that updated the record and the record data before the update as field values, respectively. How to provide. 2. A database query process is implemented by using a version provided by the method for providing a version of a transaction in the database query process according to claim 1 to achieve a desired isolation level in the transaction. Database query processing method. 3. A database integrity constraint is checked using a version provided by the transaction version providing method in the database query process according to claim 1, and a database query process is performed according to the check result. A database query processing method characterized by performing: 4. In the process of query processing in response to a query request to a database, when performing a plurality of transaction processes on the database, in addition to the record data in the record of the file of the database,
A transaction version in a database query process, wherein a version adapted to the transaction executing the query is provided by storing the ID of the transaction that updated the record and the record data before the update as field values, respectively. Offer system. 5. A database query processing is realized by realizing a desired isolation level in a transaction by using a version provided by the transaction version providing system in the database query processing according to claim 4. Database query processing system. 6. A database integrity constraint check is performed using a version provided by the transaction version providing system in the database query process according to claim 4, and a database query process is performed according to the check result. A database query processing system characterized by performing: 7. A transaction version providing apparatus comprising: a server having a database file; a client terminal for making an inquiry request to the database; and a network connecting the server and the client terminal. In the process of query processing in response to a query request to the database from the client terminal, when performing a plurality of transaction processing to the database, in the record of the file of the database, in addition to record data, the record A transaction in a database query process characterized in that an updated transaction ID and pre-update record data are stored as field values, respectively, to provide a version adapted to the transaction executing the query. Edition plate providing device. 8. A database query processing is realized by using a version provided by the transaction version providing apparatus in the database query processing according to claim 7 to realize a desired isolation level in the transaction. Database query processing device. 9. A database integrity constraint check is performed using a version provided by the transaction version providing apparatus in the database query process according to claim 7, and a database query process is performed according to the check result. A database query processing device characterized by performing: 10. In the process of query processing in response to a query request to a database, when a plurality of transaction processes are performed on the database, the record is updated in addition to record data in a record of a file in the database. Storing the transaction ID and the record data before update as field values, thereby providing a version adapted to the transaction in which the query is being executed. Computer-readable recording medium on which a program for executing the program is recorded. 11. A desired isolation level in a transaction is realized by using a version provided by executing a program for providing a version of a transaction in the database query processing according to claim 10. A computer-readable recording medium on which a program for executing a database inquiry process, which performs a database inquiry process, is recorded. 12. A database integrity constraint is checked using a version provided by executing a program for executing a version of a transaction in the database query processing according to claim 10, A computer-readable recording medium storing a program for executing a database query process, wherein the database query process is performed according to a test result.