#Tune dbvisualizer manual
For more information you can read the DB2 manual for REORGCHK.ĬALL SYSPROC. In the REORGCHECK DB2 checks whether the calculated results are still within the set bounds of corresponding formulas. You can use the following command in DB2 to find out which table needs a REORG. But this is normally the job of DBAs who are constantly monitoring the status of the database. Over time such small fragments will affect the performance of the database, unless a REORG is executed. Then the table space gets more and more fragmented. If we delete many records, the table still occupies the disk space of the deleted records. If we insert many records, there might not be enough free space to keep the records in the clustered sequence. Why? First of all a table space in DB2 is pretty much like the file system on your hard disk. Normally after a large amount of INSERT, UPDATE, DELETE activities on data tables, we generally need a REORG. When to run a REORG in DB2 When REORGCHK indicates the need of REORG On the other side, the in place REORG allows full access to the table, because the operation incrementally reorganizes the table. During the classic REORG we do not have access to the table. Basically classic REORG creates a temporary copy of the table / index, then replaces the original one with the organized copy.
There are two types of REORG: Classic REORG and In Place REORG.
The benefit we gain is that the performance of database stays tuned. This operation reconstructs the data in the table spaces or index spaces, so that the data is unfragmented and physically continuous.
The purpose of the reorganization is data clustering. To keep it simple: REORG is a database operation that is executed in DB2 to reorganize the table spaces or index spaces.
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