Introduction to Partition Key Selection

Managing Database Growth 9-7

9.3.2.1 delete_instances Procedure in Parallel

Use the delete_instances procedure in parallel to delete instances. Example 9–2 shows the syntax. Example 9–2 delete_instances Procedure in Parallel Syntax PROCEDURE delete_instances_in_parallel min_creation_date in timestamp, max_creation_date in timestamp, batch_size in integer, max_runtime in integer, retention_period in integer, DOP in integer max_count integer, purge_partitioned_component in boolean Table 9–2 describes the script parameters.

9.3.3 Purge States

Instances in the following states are purged with the purge scripts. ■ Completed successfully ■ Faulted Note: If you have a multiple CPU host, use of the parallel script can be beneficial. However, Oracle recommends that you enable the parallel script only during off hours. In addition, when purging data during off hours, Oracle recommends that you drop indexes before purging large amounts of data and then add the indexes back in. This speeds up the purge process, and also keeps indexes from becoming unbalanced. Table 9–2 delete_instances in Parallel Procedure Parameter Descriptions Parameter Description min_creation_date Beginning creation date for the composite instances. max_creation_date Ending creation date for the composite instances. batch_size Batch size used to loop the purge. The default value is 20000. max_runtime Expiration time at which the purge script exits the loop. The default value is 60. This value is specified in minutes. retention_period Retention period is only used by the BPEL process service engine only in addition to using the creation time parameter. The default value is null. For more information about this parameter, see Table 9–1 . DOP Defines the number of parallel jobs to schedule. The default value is 4. max_count Defines the number of rows processed not the number of rows deleted. A big temp table is created and then jobs are scheduled to purge based on the data. This is the maximum purge row count to use; it defaults to one million. The default value is 1000000. purge_partitioned_ component Users can invoke the same purge to delete partitioned data. The default value is false.