Database constraint relationship checking method and device

Abstract

Embodiments of this specification provide a method and device for checking a constraint relationship in a database. In the method for checking a constraint relationship, a DML operation of the first transaction is performed for a target data table in the database, and each data stored in each data table in the database is executed. Records have transaction version numbers. Enter the commit phase, and in the commit phase, determine the corresponding current transaction version number for the target data record after the DML operation. Based on the current transaction version number, the latest relevant data records visible to the first transaction are read from the target data table or its associated data table. The target data record and the field value corresponding to the target field of each related data record have a mutual restriction relationship. Based on each related data record, a constraint relationship check is performed on the target field value of the target data record corresponding to the target field. If the constraint check is passed, the first transaction is committed, otherwise it is rolled back.

Description

technical field [0001] One or more embodiments of this specification relate to the field of databases, and in particular, to a method and apparatus for checking a constraint relationship of a database. Background technique [0002] General relational databases provide a series of constraint definitions to limit the integrity of data in the database. In order to ensure that the constraints are not destroyed, after the addition, deletion and modification operation is performed on the database, it is usually necessary to check the constraint relationship of the data record after the addition, deletion and modification operation. [0003] In the traditional technology, when the constraint relationship is checked, the related data records are usually locked. For example, foreign key constraints, when adding a row of data records to a child table, it is necessary to add a shared lock to the data records corresponding to the parent table and even the entire table to prevent the pa...

AI Technical Summary

Problems solved by technology

For example, for foreign key constraints, when a row of data records is added to a child table, a shared lock needs to be added to the data records corresponding to the parent table and even the entire table to prevent the parent table from being modified or deleted, thereby ensuring the validity of the constraint relationship check. Locking usually causes the performance of the database to be affected

Images