Suppressing Log Records At A Table Level In A Multi-Table Table Space While Maintaining Data Integrity.
Publication Date: 2014-Feb-25
The IP.com Prior Art Database
Disclosed is a method for suppressing log records at a table level while preserving the integrity of the data in error cases, ROLLBACK, and ROLLBACK TO SAVEPOINT, depending on the user’s specifications.
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Suppressing Log Records At A Table Level In A Multi - Maintaining Data Integrity .
Users do not always need "UNDO" capability on tables, but users still have to use resources for writing the log records. Today, a relational database system allows suppressing log records at a table space level but provides no capability to suppress log records at a table level in a multi-table table space.
A method is herein disclosed for suppressing log records at a table level while preserving the integrity of the data in error cases, ROLLBACK, and ROLLBACK TO SAVEPOINT, depending on the user's specifications.
The user specifies during creation of schema when the log records need to be suppressed. At the same time, the user specifies the desired behavior when a ROLLBACK or ROLLBACK TO SAVEPOINT is requested. The options during ROLLBACK are to either delete all the rows from the table or preserve all the rows from the table. The user decides to use one of these options depending on whether the database should empty the table or the application should take a more suitable action.
If there is an error during the execution of a Structured Query Language (SQL) statement such that the statement cannot successfully complete, since 'UNDO' is not possible due to lack of log records, then all the rows are deleted. The table is available for new insert, update, delete, and fetch activity in the ROLLBACK case as well as the error case. The delete of rows during a ROLLBACK or ROLLBACK TO SAVEPOINT request is only performed if some update activity to the table occurred since the last COMMIT, otherwise there is nothing to UNDO and the table data is committed.
To decide whether to delete all rows from the table, the relational database application needs to track the update activity at a table level and detect if the ROLLBACK or ROLLBACK to save p...