Establishing a point of consistency

Typically, you name all of the table spaces in a table space set that you want recovered to the same point in time to avoid referential integrity violations. Alternatively, you can use the QUIESCE utility with the TABLESPACESET keyword for referential integrity-related tables.

The QUIESCE utility writes changed pages from the page set to disk. The SYSIBM.SYSCOPY catalog table records the current RBA and the timestamp of the quiesce point. At that point, neither page set contains any uncommitted data. A row with ICTYPE Q is inserted into SYSCOPY for each table space that is quiesced. Page sets DSNDB06.SYSTSCPY, DSNDB01.DBD01, DSNDB01.SYSUTILX, and DSNDB01.SYSDBDXA are an exception. Their information is written to the log. Indexes are quiesced automatically when you specify WRITE(YES) on the QUIESCE statement. A SYSIBM.SYSCOPY row with ICTYPE Q is inserted for indexes that have the COPY YES attribute.

The QUIESCE utility allows concurrency with many other utilities; however, it does not allow concurrent updates until it has quiesced all specified page sets and depending on the amount of activity, that can take considerable time. Try to run the QUIESCE utility when system activity is low.

Also, consider using the MODE(QUIESCE) option of the ARCHIVE LOG command when planning for off-site recovery. It creates a system-wide point of consistency, which can minimize the number of data inconsistencies when the archive log is used with the most current image copy during recovery.