JPWO2018056267A1 - Database management apparatus, database management method, and program - Google Patents

Abstract

The database management device 300 is a device for managing the database 200 accessed by the application 100, and receives a request from the application 100 for the record of the database 200. In the case of use, the exclusive use is permitted to the request source application 100 on condition that a certain condition is satisfied, and the authorized application 100 declares that the update of the specific record is completed. And an access processing control unit 302 which allows another application 100 to use a specific record by canceling the use.

Description

  The present invention relates to a database management apparatus and database management method for performing exclusive control in a database system, and further relates to a computer-readable recording medium recording a program for realizing these.

  Conventionally, in a database system in which a plurality of application programs (hereinafter referred to as "applications") accessing a database operate in parallel, exclusive control is introduced to ensure data consistency (patented) Reference 1 and 2). According to this exclusive control, when a plurality of applications try to update a specific record of the database at the same time, the application that can update the record is limited to one.

  Also, in the database system, generally, updating of a series of records is controlled as one transaction (hereinafter referred to as "transaction control") in order to guarantee the atomicity of the database. In this transaction control, record updating performed in one transaction is decided on the database by committing processing (commit) executed at the end of the transaction. On the other hand, if a transaction is discarded (rolled back) in the middle of a transaction, all record updates made in the transaction are also discarded.

  Also, in a database that performs transaction control, the above-mentioned exclusive control is often realized by pessimistic locking. In pessimistic locking, the application locks (locks) the record to be updated in the transaction, and then refers to and updates the record. In addition, when an application tries to apply exclusion to a specific record, if another application has already applied exclusion to this specific record, this application causes another application to confirm the update. It will wait for exclusion until the exclusion is released. Since the record data updated in the transaction is not finalized until the commit, the exclusion is released by the commit.

Japanese Patent Application Publication No. 2003-308219 JP 2012-164190 A

  As described above, in the conventional database system, although the integrity of data is secured by exclusive control, there is a problem that exclusive processing adversely affects the processing performance of the application. That is, when updating a record, a specific application will be kept waiting until another application's transaction is committed or rolled back, if the other application has already applied exclusion. As a result, if it takes time to complete the transaction being excluded, the time taken to complete the transaction by the specific application waiting for exclusion becomes long, and the processing performance of the specific application is degraded.

  This problem is described with reference to FIG. FIG. 16 is a diagram for describing exclusive control in a conventional database system. In FIG. 16, the vertical axis represents the passage of time, and also represents the order of processing in application 1 and application 2.

  In the example of FIG. 16, the application 1 and the application 2 both update the shared record for the table A, but independently update the unique record for the table B. Specifically, the application 1 updates the unique records 1-1, 1-2, and 1-3, and the application 2 updates the unique records 2-1, 2-2, and 2-3. Therefore, in the example of FIG. 16, the process of updating the shared record and the unique records 2-1 to 2-3 by the application 2 is waited until the application 1 commits.

  As described above, in the conventional database system, the application can not perform update processing of another exclusion unnecessary record because of waiting for exclusion of one record, processing performance is reduced, and processing time is wasted. Will occur.

  Also, as a specific example of such application processing, a serial number such as a reception number is issued for transactions operating in parallel, a unique serial number is assigned to each transaction, and the serial number is given in the subsequent application processing. The control used may be mentioned. In this case, the serial number is updated only when the transaction is successful, and is not generated when rolled back.

  Further, in the above-mentioned specific example, it is necessary to prepare a record for managing the serial number and exclusively update the record with a plurality of applications, so that transactions operating in parallel are serialized in the process of serial number assignment. It will It is thought that this problem can be dealt with by allowing the loop number at the time of rollback, but in the subsequent application implementation, it is forced to consider the loop number, which makes the application complicated. Problems will arise.

  One example of the object of the present invention is a database management apparatus, database management method, and computer readable method capable of solving the above problems and suppressing deterioration in processing performance of a plurality of application programs executing processing in parallel in a database system. Providing a recording medium.

In order to achieve the above object, a database management apparatus according to an aspect of the present invention is an apparatus for managing a database accessed by a plurality of application programs,
A request receiving unit for receiving a request from the application program for a record stored in the database;
An access processing control unit for permitting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied. When,
Equipped with
The access processing control unit releases the exclusive use of the specific record and permits the use when the application program permitted to use declares that the update of the specific record is to be completed. Allow application programs other than the application program to use the particular record
It is characterized by

Also, in order to achieve the above object, a database management method according to an aspect of the present invention is a method for managing a database accessed by a plurality of application programs,
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
It is characterized by having.

Further, to achieve the above object, a computer readable recording medium according to one aspect of the present invention is a computer readable recording medium recording a program for managing a database accessed by a plurality of application programs by a computer. And
On the computer
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
And recording a program including an instruction to execute the program.

  As described above, according to the present invention, it is possible to suppress a decrease in processing performance of a plurality of application programs that execute processing in parallel in a database system.

FIG. 1 is a diagram for explaining the operation of an application program under the management of a database according to the present invention. FIG. 2 is a diagram for explaining the operation of an application program under the management of a database according to the present invention. FIG. 3 is a diagram for explaining the operation of an application program under the management of a database according to the present invention. FIG. 4 is a diagram showing the processing order of each application program and the processing result in the present invention. FIG. 5 is a diagram showing a schematic configuration of a database management apparatus according to an embodiment of the present invention. FIG. 6 is a block diagram showing a specific configuration of the database management apparatus in the embodiment of the present invention. FIG. 7 is a diagram showing an example of a transaction update management table used in the embodiment of the present invention. FIG. 8 is a diagram showing an example of the record exclusion management table used in the embodiment of the present invention. FIG. 9 is a diagram showing an example of a transaction dependency management table used in the embodiment of the present invention. FIG. 10 is a flowchart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is exclusive record reading. FIG. 11 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is a record update. FIG. 12 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is the update completion of the record. FIG. 13 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is commit. FIG. 14 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is rollback. FIG. 15 is a block diagram showing an example of a computer for realizing the database management apparatus in the embodiment of the present invention. FIG. 16 is a diagram for describing exclusive control in a conventional database system.

(Summary of the Invention)
The present invention, in a plurality of application programs (hereinafter referred to as "application") that update using the same record exclusively, suppresses the influence of performance degradation due to record exclusion waiting, and performs parallel execution performance of each application Improve. Specifically, the present invention introduces the step of declaring record update completion during a transaction. Therefore, the declaration of the update completion of the record cancels exclusive use of the record during the transaction and also cancels exclusion waiting of other applications. At this time, by managing the transaction dependency of both applications, exclusive latency can be reduced while guaranteeing the atomicity of the transaction.

  Here, processing in the present invention will be described using FIGS. 1 to 3. 1 to 3 are diagrams for explaining the operation of an application program under management of a database according to the present invention.

  As shown in FIG. 1, when the transaction of the application 1 that has previously locked the target record declares the update completion, the target record is released even if the transaction of the application 1 has not been committed yet. Ru. As a result, the transaction of another application 2 that has been waiting for exclusion can be locked on the target record, and the waiting for exclusion of application 2 is released. At this time, the application 2 transaction can refer to the uncommitted target record updated by the application 1 transaction.

  Therefore, as shown in FIG. 1, since the exclusion waiting period in the application 2 is shortened, the effect of shortening the transaction processing time of the application 2 can be obtained. In addition, since the issue of the application 1 commit and the issue of the application 2 commit may occur simultaneously, the group commit function may be applied.

  Also, since the transaction of application 2 refers to a record of a state not committed by the transaction of application 1, the present invention guarantees atomicity of the database by making each transaction have a dependency. Specifically, in the present invention, the following controls (a) and (b) are performed.

(A) When the transaction of application 2 ends prior to the transaction of application 1, the transaction of application 2 is made to wait until the transaction of application 1 ends (see FIG. 2).
(B) If the transaction of application 1 is rolled back, the commit of the transaction of application 2 is rejected, and the transaction of application 2 is rolled back (see FIG. 3).

  As shown in FIG. 2, when the control of (a) is performed, the transaction of the application 2 waits for the completion of the commit of the application 1 even if the transaction of the application 2 commits first.

  As shown in FIG. 3, when the control of (b) is performed, the transaction from the application 2 is rejected from the commit from the transaction because the transaction of the application 1 detects an abnormality such as record data corruption and rolls back. Transaction 2 is rolled back.

  FIG. 4 is a diagram showing the processing order of each application program and the processing result in the present invention. FIG. 4 summarizes the order in which the application 1 and the application 2 perform commit and rollback, and the result of the execution by each application. In FIG. 4, the process is performed in the order of order 1 → order 2, and the contents described after the arrows represent the implementation results.

Embodiment
Hereinafter, a database management apparatus, a database management method, and a program according to an embodiment of the present invention will be described with reference to FIGS.

[Device configuration]
First, a schematic configuration of the database management apparatus according to the present embodiment will be described with reference to FIG. FIG. 5 is a diagram showing a schematic configuration of a database management apparatus according to an embodiment of the present invention.

  A database management apparatus 300 in the present embodiment shown in FIG. 5 is an apparatus for managing a database 200 accessed by a plurality of application programs (hereinafter referred to as “application”) 100.

  The application 100 is an arbitrary application that uses the database 200, and requests the database 200 for various operations. The operations include “read exclusive record”, “record update”, “update completion”, “commit”, and “rollback”. The operations required by the application 100 are not limited to the above. In the present embodiment, the application 100 can request an operation that can be requested to a general database as in the conventional case.

  Also, the database 200 is constructed in the storage area of the storage device, and stores various tables as data. Also, the table is composed of a plurality of records. Further, in the following description, what is simply expressed as "record" refers to records stored in the database 200 unless otherwise specified.

  As shown in FIG. 5, the database management device 300 includes a request receiving unit 301 and an access processing control unit 302. Among these, the request receiving unit 301 receives a request from the application 100 for a record stored in the database 200.

  When the request from the application 100 is exclusive use for a specific record, the access processing control unit 302 is exclusive to the application 100 requesting exclusive use on condition that a certain condition is satisfied. Permit use.

  In addition, when the application 100 permitted to use declares that the update of the specific record is to be completed, the access processing control unit 302 releases the exclusive use of the specific record. Then, the access processing control unit 302 permits the application 100 other than the application 100 permitted to use to use the specific record.

  As described above, in the present embodiment, when the application declares the update of the record during the execution of the transaction, the database management device 300 exclusively uses the record by the application even if the commit is not completed. Release Then, the database management device permits another application to use the record. Therefore, according to the present embodiment, it is possible to suppress a decrease in processing performance of the plurality of applications 100 executing processes in parallel in the database system.

  Here, a specific configuration of the database management device in the present embodiment will be described using FIGS. 6 to 9. FIG. 6 is a block diagram showing a specific configuration of the database management apparatus in the embodiment of the present invention. In FIG. 6, a solid line connecting the processing units represents a relationship in which data is exchanged between the processing units. Also, the broken line represents the relationship between the management table and the processing unit that operates it.

  As shown in FIG. 6, in the present embodiment, the database management apparatus 300 includes a record exclusion control unit 303, a dependency relationship control unit 304, and a storage processing unit in addition to the request reception unit 301 and the access processing control unit 302. And 305. Each processing unit will be specifically described below.

  As described above, the request receiving unit 301 receives a request from each of the applications 100, and passes the received request to the access processing control unit 302. Further, in the present embodiment, a plurality of request receiving units 301 are provided, and each of the request receiving units 301 corresponds to any one of the plurality of applications 100 in a one-to-one correspondence.

  In the present embodiment, the access processing control unit 302 manipulates the control data of the transaction update management table 306 in response to the request received from the request receiving unit 301. Further, the access processing control unit 302 controls access processing through each processing unit described later. Furthermore, the access processing control unit 302 has the following processing unit in order to perform processing according to the type of request.

  Specifically, in the present embodiment, the access process control unit 302 includes an exclusive process read process control unit 311, a record update process control unit 312, an update completion process control unit 313, and a commit process control unit 314. A rollback processing control unit 315 is provided.

  If the application 100 requests exclusive record reading (also referred to as “exclusive record reading”), the transactional update management table 306 corresponding to the application 100 of the request source is present. Determine if it exists. Further, in this case, the exclusive-case reading process control unit 311 determines whether exclusive-case reading is possible based on the processing result of the record exclusive control unit 303 described later.

  FIG. 7 is a diagram showing an example of a transaction update management table used in the embodiment of the present invention. As shown in FIG. 7, the transaction update management table 306 is used to manage the transaction content of the application 100. Also, a transaction update management table 306 is provided for each application 100.

  [Application ID] in FIG. 7 is an identifier for identifying the corresponding application 100 individually. The application ID is, for example, an identifier such as a process ID in a UNIX (registered trademark) system.

  [Transaction state] indicates the current transaction state of the corresponding application 100. The transaction state includes "valid" and "invalid". In the case of "valid", the access processing control unit 302 receives all the requests from the corresponding application 100. In the case of “invalid”, the access processing control unit 302 accepts only the rollback among the requests from the corresponding application 100, and rejects the other requests.

  [Table Name], [Key], [Value], and [Update] are information for identifying a record to be subjected to “exclusive read” and “update” by the corresponding transaction. [Table Name] represents the table name of the record, [Key] represents the primary key value of the record, and [Value] represents the data division value of the record.

  [Update] indicates whether the target record is updated. In the case of "present" indicates a state in which the update is being performed, and in the case of "none" indicates a state in which only "read with exclusion" is performed.

  The record update process control unit 312 checks the transaction update management table 306 in the request source application 100 when the application 100 requests a record update. Then, when the transaction state is “valid”, the record update processing control unit 312 updates the value of the corresponding record of the corresponding table of the transaction update management table 306 according to the record update request.

  The update completion process control unit 313 checks the transaction update management table 306 in the request source application 100 when the application 100 requests the record update completion. Then, when the transaction state is “valid”, the update completion process control unit 313 causes the record exclusion control unit 303 to update a record exclusion management table 307 (see FIG. 8) described later.

  The commit process control unit 314 checks the transaction update management table 306 of the request source application 100 when the application 100 requests a transaction commit. Then, when the transaction state is “valid”, the commit process control unit 314 causes the record exclusion control unit 303 to update a record exclusion management table 307 (see FIG. 8) described later.

  The rollback processing control unit 315 requests the dependency relationship control unit 304 to perform rollback processing when the application 100 requests rollback.

  The record exclusion control unit 303 manipulates the control data of the record exclusion management table 307 shown in FIG. 8 to execute exclusion control of the records of the database 200. FIG. 8 is a diagram showing an example of the record exclusion management table used in the embodiment of the present invention. As shown in FIG. 8, the record exclusion management table 307 is used to manage exclusion acquisition requests by the application 100 and to manage exclusion states for each record in the table stored in the database 200. Further, the record exclusion management table 307 is composed of a plurality of lines of "control records".

  In the following description, “control record” indicates a record stored in the record exclusion management table 307 unless otherwise specified. The record exclusion management table 307 is provided for each table stored in the database.

  Further, in the record exclusion management table 307, [table name] represents a target table name. [Key] represents the primary key value of the record. [Requester] represents the application ID of the application 100 that has requested exclusion of the corresponding record.

  The [immediately previous request source] indicates the application 100 that has requested exclusive acquisition immediately before the request source application 100 for the corresponding record. If [immediately before request source] is "none", this indicates that the application 100 that has issued the exclusion request immediately before does not exist, or that the transaction of the immediately preceding application 100 has already been completed. There is.

  Further, in the control records having the same [key], one [request source] and the other [preceding request source] match, and the two form a list structure, and the request order is managed. It is done.

  [EXCLUSIVE STATE] represents the exclusive state of the request source application 100 for the record stored in the database 200. “Waiting for exclusion” indicates an exclusion acquisition waiting state. In the case of "acquiring", it indicates a state in which the exclusion has been acquired. "Update completion" indicates that update completion has been declared after obtaining the exclusion. In control records in which the [key] is the same, there is always one control record that is "acquiring".

  The dependency control unit 304 manages the dependency of each transaction of the application 100, and updates the dependency according to the result of processing by the access processing control unit 302. In the present embodiment, the dependency control unit 304 manipulates the control data of the transaction dependency management table 308 shown in FIG. 9 to control transaction dependency among the applications 100. In the present embodiment, the dependency control unit 304 reduces the exclusion wait time while guaranteeing the atomicity of the transaction.

  FIG. 9 is a diagram showing an example of a transaction dependency management table used in the embodiment of the present invention. As shown in FIG. 9, the transaction dependency management table 308 displays the dependency of transactions in a graph structure, and is used to manage the dependencies between currently active transactions.

  Also, for each node shown in the transaction dependency management table 308, an application ID is displayed to identify a transaction. It can be said that the transaction dependency management table 308 manages “application ID”. Also, in the transaction dependency management table 308, the arrows indicate the dependency between nodes, and the direction of the arrow is set from the parent node to the child node.

  It is assumed that a record that has been updated by one application 100 is acquired exclusively by another application 100. In this case, in the transaction dependency management table 308, the application 100 that has completed the update is displayed as a parent node, and the application 100 that has been exclusively acquired is displayed as a child node.

  Therefore, according to the transaction dependency management table 308, it can be judged by the existence of the parent node whether the transaction can be committed. Also, in the transaction dependency management table 308, if there is no parent node, it can be determined that the commit can be executed immediately. On the other hand, if the parent node exists, it can be determined that the execution of the commit should be waited until the transaction of the parent node is committed.

  Furthermore, in the transaction dependency management table 308, if commit is executed, the corresponding node is deleted, and if rollback is performed, the corresponding node and its descendant nodes are deleted. Further, in the transaction dependency management table 308, a descendant node means a node including all of a child node and a child node before that.

  The storage processing unit 305 executes data acquisition and data update of records on storage devices (storages) that constitute the database 200.

[Operation explanation]
Next, the operation of the database management device 300 according to the embodiment of the present invention will be described with reference to FIGS. Further, in the present embodiment, the database management method is implemented by operating the database management device 300. Therefore, the description of the database management method in the present embodiment is replaced with the following description of the operation of the database management apparatus 300.

  Also, in the following, when the request by the application 100 is “exclusive record read”, “record update”, “update complete”, “commit”, and “rollback”, each will be described.

[Exclusive record read]
First, the operation of the database management device 300 when the application 100 requests reading of the exclusive record will be described using FIG. FIG. 10 is a flowchart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is exclusive record reading. Hereinafter, the application ID of the request source application 100 will be described as “AP001”.

  As shown in FIG. 10, first, the request receiving unit 301 receives from the application 100 a request for reading an exclusive record (step A1). Specifically, the request receiving unit 301 receives from the application 100 the table name of the table to be read and the key value of the record to be read as information, and the received information is excluded from the access processing control unit 302. It is passed to the read processing control unit 311.

  Next, the exclusive process read process control unit 311 determines whether the transaction update management table 306 corresponding to the application for which the application ID is requested exists (step A2). Specifically, for example, assuming that the requested application ID is “AP001”, the exclusive-read processing control unit 311 determines that the transaction update management table 306 in which the application ID is set to “AP001” exists. Determine if there is.

  If the corresponding transaction update management table 306 does not exist as a result of the determination in step A2, the exclusive read processing control unit 311 newly creates the transaction update management table 306 in which the application ID is set to “AP001” (step A3). In addition, the exclusive read processing control unit 311 sets the transaction state in the created transaction update management table 306 to “valid”.

  On the other hand, if the corresponding transaction update management table 306 exists as a result of the determination in step A2, and after execution of step A3, the read-with-exclusion processing control unit 311 determines that the transaction state of the transaction update management table 306 is "valid". It is determined whether or not (step A4).

  As a result of the determination in step A4, when the transaction state is "invalid", the exclusive process read process control unit 311 returns an error to the requested application 100 through the request receiving unit 301 (step A5). In this case, the process in the database management device 300 is temporarily ended.

  On the other hand, if the transaction state is "valid" as a result of the determination in step A4, the exclusive read processing control unit 311 causes the record exclusion control unit 303 to confirm the exclusive state of the record requested by the request source application ( Step A6).

  Specifically, the exclusive read processing control unit 311 passes the ID (“AP001”) of the request source application 100 and the table name of the exclusion target record and the key value to the record exclusion control unit 303. Thereby, the record exclusion control unit 303 reads the control record from the record exclusion management table 307 for the corresponding table, and confirms the exclusion state of the exclusion target record.

  Next, the record exclusion control unit 303 determines whether update completion has been declared for the exclusion target record by another application 100 other than the request source application 100 (step A7).

  When the update completion is not declared for the exclusion target record as a result of the determination of step A7, the record exclusion control unit 303 executes the exclusion control according to the status of the exclusion state (step A8). On the other hand, as a result of the determination in step A7, when update completion is declared for the exclusion target record, the record exclusion control unit 303 causes the dependency relationship control unit 304 to execute processing according to the status of the dependency relationship (steps A9).

  Here, steps A7 to A9 will be specifically described. First, in step A7, the record exclusion control unit 303 reads the control record from the record exclusion management table 307 for the corresponding table, and confirms the exclusion state of the exclusion target record. Subsequently, the record exclusion control unit 303 determines which of the following patterns 1 to 5 the exclusion state corresponds to.

Pattern 1: A control record does not exist in the record exclusion management table 307.
Pattern 2: A control record in which "exclusive state" is "acquiring" is present, and [request source] is the request source application 100 ("AP001").
Pattern 3: A control record in which “exclusive state” is “acquiring” is present, and “request source” is an application 100 different from the request source application 100 (“AP001”).
Pattern 4: Only the control record of which “exclusion state” is “update completion” exists, and the exclusion acquirer is the request source application 100 (“AP001”).
Pattern 5: Only the control record having the “exclusion state” of “update completed” is present, and the exclusion acquirer is the application 100 different from the request source application 100 (“AP001”).

  And when it corresponds to the patterns 1-4, it becomes No in step A7, and the record exclusion control part 303 performs step A8. The specific content of step A8 is as follows.

  In the case where the pattern 1 is applied, since the other application 100 does not exclude the corresponding record, the request source application 100 can obtain exclusive acquisition. Also, the data of the record in the database 200 is the latest data of the record. Therefore, the record exclusion control unit 303 newly adds the control record of the corresponding record to the record exclusion management table 307 of the corresponding table, sets [request source] as the ID (“AP001”) of the request source application 100, and Exclusive status] is set to "acquiring". Also, the record exclusion control unit 303 sets [immediately previous request source] to “none”.

  Thereafter, the record exclusion control unit 303 returns “exclusive acquirer not present” to the exclusive processing read processing control unit 311. In this way, the exclusive read processing control unit 311 requests the storage processing unit 305 to read the corresponding record, and registers the acquired data in the transaction update management table 306 of the request source application 100. At this time, "update" is "none". Thereafter, the exclusive read processing control unit 311 passes the record data to the request source application 100 through the request reception unit 301.

  When the pattern 2 is applied, the request source application 100 reads the exclusive record again for the corresponding record. At this time, the record exclusion control unit 303 causes the exclusive read processing control unit 311 to acquire data of the corresponding record from the transaction update management table 306 of the request source application 100. Thereafter, the exclusive access reading process control unit 311 passes the record data to the request source application 100 through the request receiving unit 301.

  In the case of pattern 3, since another application 100 has acquired exclusion, it is waiting for exclusion acquisition. If the control record of the request source application 100 for the corresponding record does not exist, the record exclusion control unit 303 newly adds a control record to the record exclusion management table 307. Then, the record exclusion control unit 303 sets [request source] to the ID (“AP001”) of the request source application 100, and sets [exclusion state] to “acquisition waiting”. Further, the record exclusive control unit 303 sets the [request source] of the control record added with the same [key] to the [previous request source] last.

  On the other hand, when the control record of the request source application 100 with respect to the corresponding record already exists, the record exclusion control unit 303 does not add the control record, and returns the exclusion processing to the exclusive process processing unit 311 with exclusion. By this, the exclusive read processing control unit 311 instructs the request reception unit 301 to retry the request after the standby.

  When the pattern 4 is applied, the request source application 100 acquires the exclusion again for the record for which the update completion has been once declared. Exclusive acquisition is prohibited for a record that has been declared to be updated once. Therefore, the record exclusion control unit 303 returns the exclusion acquisition rejection to the exclusion processing read processing control unit 311, and notifies the request source application 100 of exclusion acquisition rejection through the request reception unit 301.

  When it corresponds to the pattern 5, it becomes Yes in step A7, and the record exclusion control unit 303 executes step A9. Specifically, in the case where the pattern 5 is applied, the request source application 100 tries to acquire exclusion for a record for which update completion has been declared by another application 100.

  Here, a specific example will be described below, assuming that the ID of the application 100 that has declared update completion is “AP002”. In this case, if the control record of the request source application 100 ("AP001") for the corresponding record exists in the record exclusion management table 307, the record exclusion control unit 303 changes the "exclusive status" from "waiting for acquisition". Update to "acquiring". On the other hand, when the control record of the request source application 100 (“AP001”) for the corresponding record does not exist, the record exclusion control unit 303 newly adds the same control record.

  Thereafter, the record exclusion control unit 303 returns the exclusion acquisition available status to the exclusion processing read processing control unit 311 of the access processing control unit 302, and further, the ID of the application 100 that has declared update completion ("AP002"). ) Also returns.

  Subsequently, in the access processing control unit 302, the exclusive processing for reading processing control unit 311 requests the dependency control unit 304 to register the dependency when the parent node becomes “AP002” and the child node becomes “AP001”. Do. The dependency control unit 304 refers to the transaction dependency management table 308 to check whether the registration request from the exclusive read processing control unit 311 can be registered.

  Specifically, the dependency relationship control unit 304 determines which of the following patterns 6 to 9 corresponds to, and executes processing according to the determination result.

Pattern 6: The corresponding dependency is already registered.
Pattern 7: A node corresponding to a new child node ("AP001") does not exist.
Pattern 8: A node corresponding to a new child node ("AP001") exists, but the corresponding dependency is not registered. Also, as a descendant node of the new child node, the new parent node ("AP002") does not exist.
Pattern 9: A node corresponding to a new child node ("AP001") exists, but the corresponding dependency is not registered. However, a new parent node ("AP002") exists as a descendant node of the new child node.

  In the case where the pattern 6 is applied, the application 100 “AP001” has acquired exclusion for the record that the application 100 “AP002” has completed updating in another record. Therefore, the corresponding dependency relationship already exists, and the registration processing by the dependency relationship control unit 304 is not necessary.

  When the patterns 7 and 8 are satisfied, the exclusive read processing control unit 311 newly registers the dependency because the requested dependency is in a state in which the requested dependency can be registered. If there is any node, the exclusive read processing control unit 311 adds a node.

  In addition, in the patterns 6 to 8, when the registration is completed, the dependency relationship control unit 304 returns the registration completion to the exclusive process read process control unit 311. The latest record data of the corresponding record is the updated data of the application 100 ("AP002") that has declared update completion.

  Therefore, the exclusive process read process control unit 311 acquires the data of the corresponding record from the transaction update management table 306 with the application ID “AP002”, and the acquired data is transmitted to the request source application 100 (“AP001”). Pass to "). As a result, the record updated in the transaction of the other application 100 ("AP002") can be read with exclusion without waiting for exclusion.

  Furthermore, in the case where pattern 9 applies, a dependency opposite to the dependency that has received the registration request is already registered. For example, the case where the application 100 ("AP002") has exclusively acquired the record on which the application 100 ("AP001") has been updated is already applicable. In this case, since the dependency relationship is circulated, a deadlock occurs in waiting for the completion of the transaction of the parent node at the time of commit described later. Therefore, the deadlock is eliminated by invalidating the transaction of the new parent node by the following process so as not to become a deadlock.

  Specifically, the dependency relationship control unit 304 deletes the new parent node ("AP002") and its descendant nodes from the transaction dependency management table 308. After that, “re-determination” is returned to the exclusive process reading process control unit 311, and the ID list of the application 100 corresponding to the deleted node is returned.

  The exclusive read processing control unit 311 updates the transaction state of the transaction update management table 306 of the application 100 to “invalid” in order to invalidate the transactions of all the deleted applications 100.

  Next, the exclusive access reading process control unit 311 passes the ID list of the application 100 that has been invalidated to the record exclusion control unit 303, and requests determination of exclusion acquisition again. The record exclusion control unit 303 confirms the record exclusion management table 307, and deletes the control record in which the ID of the invalidated application 100 is set to [request source].

  In addition, the record exclusive control unit 303 sets the setting value of [previous request source] in the control record in which the setting value of [previous request source] is deleted to the control record in which the ID of the invalidated application 100 is set to [immediate request source]. Change to the setting value of [Previous request source] that has been set. That is, the record exclusion control unit 303 separates the control record of the request source application 100 that has become invalid from the list structure of the control record that manages the exclusion order, and reconnects the remaining valid control records. After that, the record exclusion control unit 303 confirms the [immediately previous request source] in the ID (“AP001”) whose [request source] is the request source application 100 in the control record of the corresponding record. At this time, there are the following two patterns.

Pattern 10: [immediately before request source] is "none".
Pattern 11: The ID of another application 100 is set in [immediately before request source].

  In the case of pattern 10, since the transaction is valid and there is no other application 100 that is updating the corresponding record, the record data stored in the database 200 becomes the latest data. Since this is the same as the pattern 1 described above, the record data is returned to the request source application 100 ("AP001") by performing the operation as in the pattern 1, and the exclusion acquisition is established.

  In the case of pattern 11, there is another application 100 in which the transaction is valid and the corresponding record is updated. Therefore, the request source application 100 ("AP001") needs to register the transaction dependency as a child node of the application 100. Since this is the same as the pattern 5 described above, registration of the transaction dependency is re-executed. In addition, when this re-registration is repeatedly executed, finally, it becomes one of the patterns 6, 7, 8, and 10, and the exclusion acquisition is completed.

Update Record
Next, the operation of the database management device 300 when the application 100 requests a record update to a record being read with exclusion will be described using FIG. FIG. 11 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is a record update.

  As shown in FIG. 11, first, the request receiving unit 301 receives a request for updating a record from the application 100 (step B1). In addition, the request receiving unit 301 passes the received request to the record update processing control unit 312 of the access processing control unit 302.

  Next, the record update processing control unit 312 checks the transaction update management table 306 of the request source application 100, and determines whether the transaction state is "valid" (step B2).

  If the transaction status is "invalid" as a result of the determination in step B2, the record update processing control unit 312 notifies the request source application 100 of the update failure through the request reception unit 301 (step B3).

  On the other hand, if the transaction state is “valid” as a result of the determination in step B2, the record update processing control unit 312 updates the value of the corresponding record in the corresponding table stored in the transaction update management table 306, Update] is updated to "Yes" (step B4).

  Next, after execution of step B4, the record update processing control unit 312 notifies the request source application 100 of update success via the request reception unit 301 (step B5).

[Update completed]
Next, the operation of the database management device 300 when the application 100 requests the record update completion to the record being read with exclusion will be described using FIG. FIG. 12 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is the update completion of the record.

  As shown in FIG. 12, first, the request receiving unit 301 receives a request for update completion of a record from the application 100 (step C1). Further, the request receiving unit 301 passes the received request to the update completion processing control unit 313 of the access processing control unit 302.

  Next, the update completion process control unit 313 checks the transaction update management table 306 of the request source application 100, and determines whether the transaction state is “valid” (step C2).

  As a result of the determination in step C2, when the transaction state is "invalid", the update completion processing control unit 313 notifies the request source application 100 of a failure through the request reception unit 301 (step C3).

  On the other hand, if the transaction state is “valid” as a result of the determination in step C2, the update completion control unit 313 requests the record exclusion control unit 303 to complete the update. Thereby, the record exclusion control unit 303 confirms the record exclusion management table 307, updates the state of the corresponding control record from "acquiring" to "update completion", and returns processing completion (step C4).

  Next, after execution of step C4, the update completion processing control unit 313 notifies the request source application 100 of processing completion through the request receiving unit 301 (step C5).

[commit]
Next, the operation of the database management device 300 when the application 100 requests a transaction commit will be described using FIG. FIG. 13 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is commit.

  As shown in FIG. 13, first, the request receiving unit 301 receives a request for committing a transaction from the application 100 (step D1).

  Next, the request receiving unit 301 passes the received request to the commit processing control unit 314 of the access processing control unit 302. Thereby, the commit process control unit 314 confirms the transaction update management table 306 of the request source application 100, and determines whether the transaction state is "valid" (step D2).

  As a result of the determination in step D2, when the transaction state is "invalid", the commit processing control unit 314 notifies the request source application 100 of commit failure through the request reception unit 301 (step D3).

  On the other hand, if the transaction state is "valid" as a result of the determination in step D2, the commit processing control unit 314 requests the dependency relationship control unit 304 to confirm whether the request source application 100 can commit. Thereby, the dependency relationship control unit 304 determines whether the request source application 100 can commit (step D4).

  Specifically, in step D4, the dependency control unit 304 refers to the transaction dependency management table 308, and determines whether or not a parent node exists in the node of the request source application 100. This indicates that if the request source application 100 has a parent node, the request source application 100 excludes the update completion record of the other application 100 and the other application 100 has not completed the commit. It is because In addition, when no parent node exists in the node of the request source application 100, the request source transaction does not already depend on another transaction, and therefore, it is possible to commit.

  As a result of the determination in step D2, if the commit is not possible, that is, if the parent node exists, the dependency relationship control unit 304 determines that the application 100 of the parent node needs to wait for commit, and the commit process control unit "Wait for commit" is returned to 314. As a result, the commit processing control unit 314 requests the request reception unit 301 to execute step D2 again after waiting (step D5). As a result, the request receiving unit 301 enters the standby state, and causes the commit processing control unit 314 to execute the determination of step D2 again after the set time has elapsed.

  On the other hand, if the result of determination in step D2 indicates that commit is possible, ie, there is no parent node, the dependency relationship control unit 304 deletes the node of the request source application 100 from the transaction dependency management table 308. , "Committable" is returned to the commit processing control unit 314.

  Thereby, the commit processing control unit 314 refers to the transaction update management table 306 of the request source application 100, extracts all the record data for which "update" is "present", and requests the storage processing unit 305 to write. Do. Thereby, the record of the database 200 is updated (step D6).

  Next, when the writing in step D6 is completed, the commit process control unit 314 requests the record exclusion control unit 303 to release the exclusion in order to release the exclusion record of the request source application 100. Thereby, the record exclusion control unit 303 deletes all control records whose [request source] is the application ID of the request source application 100 from all the record exclusion management tables 307 (step D7).

  Further, in step D7, “previous request source” is set to “none” for a control record in which the record exclusion control unit [previous request source] is the application ID of the request source application 100. The record exclusion control unit 303 notifies the commit processing control unit 314 of the completion.

  Next, the commit processing control unit 314 requests the dependency control unit 304 to release the transaction dependency of the request source application 100. The dependency control unit 304 deletes the node of the request source application 100 from the transaction dependency management table 308 (step D8).

  Next, when the record exclusion in step D7 and the deletion of the transaction dependency relationship in step D8 are completed, the commit processing control unit 314 deletes the transaction update management table 306 of the request source application 100 (step D9).

  Then, the commit processing control unit 314 notifies the request source application 100 of the completion of the commit through the request receiving unit 301 (step D10).

[roll back]
Finally, the operation of the database management device 300 at the time of rollback will be described using FIG. FIG. 14 is a flow chart showing the operation of the database management apparatus in the embodiment of the present invention when the request by the application is rollback.

  As shown in FIG. 14, first, the request receiving unit 301 receives a rollback request from the application 100 (step E1). Further, the request receiving unit 301 passes the received request to the rollback processing control unit 315 of the access processing control unit 302.

  Next, the rollback process control unit 315 requests the dependency relationship control unit 304 to perform the rollback process. Upon receiving the rollback request, the dependency relationship control unit 304 confirms the transaction dependency management table 308, and deletes the node of the request source application 100 and all of its descendant nodes (step E2). Further, in step E2, the dependency relationship control unit 304 returns the ID list of the application 100 corresponding to the deleted descendant node to the rollback processing control unit 315 as a transaction invalidity list.

  Next, the rollback processing control unit 315 passes the ID of the request source application 100 and the ID list of the application 100 for which the transaction returned from the dependency relationship control unit 304 is invalidated to the record exclusion control unit 303. Then, the rollback processing control unit 315 requests the record exclusion control unit 303 to release the record exclusion of the application 100.

  As a result, the record exclusion control unit 303 deletes all the control records for which the passed application ID is set to [request source] from the record exclusion management table 307 (step E3). In addition, if there is a control record in which the passed application ID is set to [immediately before request source], the record exclusion control unit 303 updates the value of [immediately before request source], and the list of record exclusion request order is displayed. Reconnect.

  Finally, the rollback processing control unit 315 deletes the transaction update management table 306 of the request source application 100 (step E4). Further, the rollback processing control unit 315 updates the [state] of the transaction update management table 306 to “invalid” for all the applications 100 in the transaction invalidity list received from the dependency relationship control unit 304. As a result, the transaction of another application 100 for which the request source application 100 has acquired an exclusion for the updated record is invalidated.

[Effect by the embodiment]
As described above, in the present embodiment, when the conditions of pattern 5 and patterns 6 to 8 are satisfied at the time of reading the exclusive record, the application under exclusive acquisition is excluded in the plurality of applications 100 that exclude the same record. Another application 100 will be able to obtain exclusion before 100 transactions are committed. Therefore, according to the present embodiment, the exclusive waiting time is shortened, and a decrease in processing performance of the plurality of applications 100 executing processes in parallel in the database system is suppressed.

[Modification]
Then, the modification in this embodiment is explained. According to this modification, it is possible to apply the group commit function to two transactions that exclude the same record.

  Here, the group commit function will be described. In general, a conventional database system represented by Oracle (registered trademark) or MySQL (registered trademark) has a group commit function of collectively committing a plurality of completed transactions to storage. Although commit is an expensive process that requires writing to storage, etc., the group commit function enables commit processing of multiple transactions to be performed at one time, so overhead of commit processing can be suppressed. Become. Therefore, the group commit function can be expected to improve transaction throughput.

  However, since transactions that exclude the same record are serialized in the commit process, it is impossible to simultaneously complete these transactions using the group commit function. As described with reference to FIG. 16 described above, two commits do not occur simultaneously because there is an exclusion release of the shared record between the application 1 commit and the application 2 commit.

  It is also conceivable that the group commit function can be applied to two transactions excluding the same record by buffering the storage write at the commit. However, in this case, since the data persistence to the storage is not guaranteed for the commit, the fault tolerance is reduced.

  For this reason, in the present modification, the group commit function is coped with by performing control at the time of commit so that the commit is performed when the determined number of commit requests are collected. The details will be described below.

  In this modification, when the commit processing control unit 314 receives a commit request from the request receiving unit 301, after confirming that the transaction state is "valid", whether the determined number of commit requests have arrived or not Check. If not received, the commit process control unit 314 suspends the commit process until the commit request from another request receiving unit 301 is received. If the number of commit requests has already reached, the commit processing control unit 314 proceeds with the commit processing.

  Further, when proceeding with the commit process, the commit process control unit 314 passes the application ID list of the application 100 in the commit request to the dependency relationship control unit 304, and requests the determination of whether or not commit is possible for each. Thus, the dependency control unit 304 refers to the transaction dependency management table 308 and confirms whether or not a parent node exists in the node of each application 100.

  Even when the parent node exists, if the node is a node of the application 100 that is requesting a commit, the dependency relationship control unit 304 determines that the commit is possible. The dependency relationship control unit 304 determines the application 100 capable of committing and the application 100 waiting for committing, and returns the determination result to the commit processing control unit 314.

  The commit process control unit 314 acquires all update data stored in the corresponding transaction update management table 306 for the application 100 determined to be committable. Then, it is assumed that a plurality of update data in which the table name and the key value of the record match exist in the acquired update data. In this case, the commit process control unit 314 causes the dependency relationship control unit 304 to select the child node of the lowest layer in the transaction dependency relationship among the plurality of applications 100 whose update records have been updated. Ask to confirm.

  When the application 100 corresponding to the lowermost child node can be confirmed, the commit processing control unit 314 leaves only the record data of the corresponding application 100 and discards the same record data updated by the application 100 of the parent node. . This is because when updating the same record in the database 200, only the newest record needs to be updated. In addition, the transaction update management table 306 of the application 100 which is the lowermost child node holds the newest record data.

  Then, the commit processing control unit 314 requests the storage processing unit 305 to write to the database 200 when all the updated record data are collected. Further, when writing to the database 200 is completed, the commit process control unit 314 requests the record exclusion control unit 303 to release the exclusion of the application 100 that has performed the commit, and further requests the dependency control unit 304 to delete the dependency relationship. Do.

  Further, when the control processing unit 314 can delete each control record, the request reception unit 301 notifies all the applications 100 that have completed the commit of the completion of the commit.

  This enables a plurality of applications 100 exclusive of the same record to collectively commit by group commit.

Deadlocks and their workarounds
Here, possible deadlocks occurring in the present embodiment and their workarounds will be described. The pattern 9 in the exclusive record reading described above is a state in which a deadlock due to a transaction dependency has occurred.

  Generally, when two transactions exclude two records (for example, record A and record B), one transaction acquires exclusive acquisition in the order of record A → record B, and the other transaction Occurs when the exclusive acquisition is performed in the order of record B → record A.

  In such a case, deadlock can be prevented from occurring by unifying the exclusive acquisition order of records in all transactions. However, in the present embodiment, even if the exclusive acquisition order of records is unified, there is a possibility that a deadlock will occur. For example, consider a case where two transactions (for example, transaction 1 and transaction 2) acquire exclusions in the order of record A → record B.

  Transaction 1 declares update completion immediately after exclusive update of record A. Another transaction 2 exclusively updates the record A after update completion of transaction 1 and declares update completion. Thereafter, transaction 2 acquires and updates the exclusion of record B earlier than transaction 1 and declares the update completed. Thereafter, transaction 1 gets the exclusion of record B. At this time, since the dependency between transaction 1 and transaction 2 circulates, one or both transactions become invalid in the present embodiment.

  In order to prevent such a transaction abnormality from occurring, immediately after acquiring and updating the exclusion of record A, updating of record A is not completed, but after acquiring exclusion of record B, record A Declare the update completion of. That is, by completing update of record A after transaction 1 excludes record B, transaction 2 can be prevented from excluding record B earlier than transaction 1. Therefore, in the present embodiment, the above-described processing is performed.

[program]
The program according to the present embodiment includes steps A1 to A9 shown in FIG. 10, steps B1 to B5 shown in FIG. 11, steps C1 to C5 shown in FIG. 12, steps D1 to D10 shown in FIG. It may be a program that executes steps E1 to E4 shown. By installing this program in a computer and executing it, the database management apparatus 300 and the database management method in the present embodiment can be realized. In this case, a central processing unit (CPU) of the computer functions as the request reception unit 301, the access processing control unit 302, the record exclusion control unit 303, the dependency relationship control unit 304, and the storage processing unit 305 to perform processing.

  Also, the program in the present embodiment may be executed by a computer system constructed by a plurality of computers. In this case, for example, each computer may function as any of the request reception unit 301, the access processing control unit 302, the record exclusion control unit 303, the dependency relationship control unit 304, and the storage processing unit 305. In addition, the storage unit 50 may be constructed on a computer different from the computer that executes the program in the present embodiment.

Physical configuration
Here, a computer for realizing the database management apparatus 300 by executing the program according to the present embodiment will be described with reference to FIG. FIG. 15 is a block diagram showing an example of a computer for realizing the database management apparatus in the embodiment of the present invention.

  As shown in FIG. 15, the computer 110 includes a CPU 111, a main memory 112, a storage device 113, an input interface 114, a display controller 115, a data reader / writer 116, and a communication interface 117. These units are communicably connected to each other via a bus 121.

  The CPU 111 develops the program (code) in the present embodiment stored in the storage device 113 in the main memory 112 and executes various operations by executing these in a predetermined order. The main memory 112 is typically a volatile storage device such as a dynamic random access memory (DRAM). In addition, the program in the present embodiment is provided in the state of being stored in computer readable recording medium 120. The program in the present embodiment may be distributed on the Internet connected via communication interface 117.

  Further, as a specific example of the storage device 113, besides a hard disk drive, a semiconductor storage device such as a flash memory may be mentioned. The input interface 114 mediates data transmission between the CPU 111 and an input device 118 such as a keyboard and a mouse. The display controller 115 is connected to the display device 119 and controls the display on the display device 119.

  The data reader / writer 116 mediates data transmission between the CPU 111 and the recording medium 120, and executes reading of a program from the recording medium 120 and writing of the processing result in the computer 110 to the recording medium 120. The communication interface 117 mediates data transmission between the CPU 111 and another computer.

  In addition, specific examples of the recording medium 120 include general-purpose semiconductor storage devices such as CF (Compact Flash (registered trademark) and SD (Secure Digital), magnetic recording media such as flexible disk (Flexible Disk), or CD-ROM. Optical recording media such as (Compact Disk Read Only Memory) can be mentioned.

  Note that the database management device 300 in the present embodiment can also be realized by using hardware corresponding to each unit, not a computer on which a program is installed. Furthermore, the database management device 300 may be partially realized by a program, and the remaining portion may be realized by hardware.

  A part or all of the embodiment described above can be expressed by (Appendix 1) to (Appendix 12) described below, but is not limited to the following description.

(Supplementary Note 1)
An apparatus for managing a database accessed by a plurality of application programs, the apparatus comprising:
A request receiving unit for receiving a request from the application program for a record stored in the database;
An access processing control unit for permitting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied. When,
Equipped with
The access processing control unit releases the exclusive use of the specific record and permits the use when the application program permitted to use declares that the update of the specific record is to be completed. Allow application programs other than the application program to use the particular record
Database management apparatus characterized in that.

(Supplementary Note 2)
The access processing control unit cancels exclusive use of the specific record even when the application program permitted to use declares that the update of the specific record is completed in the middle of a transaction. ,
The database management device according to appendix 1.

(Supplementary Note 3)
The system further comprises a dependency control unit that manages the transaction dependency of each of the plurality of application programs,
The dependency control unit updates the dependency according to the result of processing by the access processing control unit.
The database management device according to appendix 2.

(Supplementary Note 4)
The access processing control unit commits transactions of all the requesting applications, on condition that the number of requested commits is equal to or greater than a set number, when the request is a transaction commit.
The database management device according to any one of appendices 1 to 3.

(Supplementary Note 5)
A method for managing a database accessed by a plurality of application programs, comprising:
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
A database management method comprising:

(Supplementary Note 6)
In the step (c), even if the application program authorized for use declares that the update of the specific record is completed in the middle of a transaction, exclusive use of the specific record is released. Do,
The database management method according to appendix 5.

(Appendix 7)
(D) managing the transaction dependency of each of the plurality of application programs;
In the step (d), the dependency is updated according to the result of the process in the steps (b) and (c),
The database management method according to appendix 6.

(Supplementary Note 8)
(E) committing the transactions of all the requesting applications on condition that the number of requested commits is equal to or greater than a set number if the request is a transaction commit;
The database management method according to any one of appendices 5 to 7.

(Appendix 9)
A computer readable recording medium having recorded thereon a program for managing a database accessed by a plurality of application programs by a computer.
On the computer
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
A computer readable storage medium storing a program, comprising: instructions for executing the program.

(Supplementary Note 10)
In the step (c), even if the application program authorized for use declares that the update of the specific record is completed in the middle of a transaction, exclusive use of the specific record is released. Do,
The computer-readable recording medium according to appendix 9.

(Supplementary Note 11)
The program is stored in the computer
(D) further including an instruction to execute a step of managing a transaction dependency of each of the plurality of application programs,
In the step (d), the dependency is updated according to the result of the process in the steps (b) and (c),
The computer-readable recording medium according to appendix 10.

(Supplementary Note 12)
The program is stored in the computer
(E) an instruction to further execute the step of committing the transaction of all the requesting applications, on condition that the number of requested commits is equal to or greater than a set number, when the request is a transaction commit; Further include,
The computer readable recording medium according to any one of appendices 9-11.

Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above embodiment. The configurations and details of the present invention can be modified in various ways that can be understood by those skilled in the art within the scope of the present invention.

This application claims priority based on Japanese Patent Application No. 2016-183492 filed on Sep. 20, 2016, the entire disclosure of which is incorporated herein.

  As described above, according to the present invention, it is possible to suppress a decrease in processing performance of a plurality of application programs that execute processing in parallel in a database system. The present invention is useful for a system that processes a large number of transactions at high speed, for example, a tracking system represented by an air traffic control system, a accounting system, and the like.

100 application program 110 computer 111 CPU
112 main memory 113 storage device 114 input interface 115 display controller 116 data reader / writer 117 communication interface 118 input device 119 display device 120 recording medium 121 bus 200 database 300 database management device 301 request reception unit 302 access processing control unit 303 record exclusive control Part 304 Dependency control part 305 Storage processing part 306 Transaction update management table 307 Record exclusion management table 308 Transaction dependence management table 311 Exclusive read processing control part 312 Record update processing control part 313 Update completion processing control part 314 Commit processing control part 315 Rollback processing control unit

The present invention, for performing exclusive control of the database system, a database management method device and database management, further relates to a program for implementing them.

One example of the object of the present invention is to provide a database management apparatus, database management method, and program capable of solving the above problems and suppressing deterioration in processing performance of a plurality of application programs executing processing in parallel in a database system It is to do.

Furthermore, in order to achieve the above object, a program according to an aspect of the present invention, by a computer, a program for managing the database accessed by the plurality of application programs,
On the computer
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
Ru allowed to run, and wherein a call.

(Appendix 9)
The computer, a program for managing the database accessed by the plurality of application programs,
On the computer
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
Ru is the execution, program.

(Supplementary Note 10)
In the step (c), even if the application program authorized for use declares that the update of the specific record is completed in the middle of a transaction, exclusive use of the specific record is released. Do,
The program described in Supplementary Note 9.

(Supplementary Note 11)
Before Symbol computer,
(D) further executing the step of managing the transaction dependency of each of the plurality of application programs ;
In the step (d), the dependency is updated according to the result of the process in the steps (b) and (c),
The program according to appendix 10.

(Supplementary Note 12)
Before Symbol computer,
When (e) the request is a transaction commit, on condition that the number of the requested committed is equal to or greater than a set number, to commit all said application transaction requesting, Ru further perform the steps ,
The program according to any one of appendices 9-11.

Claims (6)

An apparatus for managing a database accessed by a plurality of application programs, the apparatus comprising:
A request receiving unit for receiving a request from the application program for a record stored in the database;
An access processing control unit for permitting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied. When,
Equipped with
The access processing control unit releases the exclusive use of the specific record and permits the use when the application program permitted to use declares that the update of the specific record is to be completed. Allow application programs other than the application program to use the particular record
Database management apparatus characterized in that. The access processing control unit cancels exclusive use of the specific record even when the application program permitted to use declares that the update of the specific record is completed in the middle of a transaction. ,
The database management device according to claim 1. The system further comprises a dependency control unit that manages the transaction dependency of each of the plurality of application programs,
The dependency control unit updates the dependency according to the result of processing by the access processing control unit.
The database management device according to claim 2. The access processing control unit commits transactions of all the requesting applications, on condition that the number of requested commits is equal to or greater than a set number, when the request is a transaction commit.
The database management device according to any one of claims 1 to 3. A method for managing a database accessed by a plurality of application programs, comprising:
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
A database management method comprising: A computer readable recording medium having recorded thereon a program for managing a database accessed by a plurality of application programs by a computer.
On the computer
(A) receiving a request from the application program for a record stored in the database;
(B) granting exclusive use to the application program requiring exclusive use, provided that the request is exclusive use for a specific record, on condition that a certain condition is satisfied; When,
(C) When the application program authorized for use declares that the update of the specific record is completed, the exclusive use for the specific record is released and the application program other than the application program authorized for use Allowing the application program in question to use the particular record,
A computer readable storage medium storing a program, comprising instructions for executing the program.

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