1 – Column Group
Column_Group=(column-list) Specifies a list of columns that comprise a single column group. The columns specified must be a valid column group for a table specified with the Tables=(table-list) qualifier. (Use the RMU Show Optimizer_Statistics command to display a valid column groups.) When you specify the Column_Group qualifier, the entire record in the RDB$WORKLOAD system table that holds data for the specified column group is deleted. Therefore, the next time you issue the RMU Collect Optimizer_Statistics command, statistics for the specified column-group are not collected.
2 – Log
Log Nolog Log=file-name Specifies whether the statistics deleted from the RDB$WORKLOAD system table are to be logged. Specify the Log qualifier to have the information displayed to SYS$OUTPUT. Specify the Log=file- spec qualifier to have the information written to a file. Specify the Nolog qualifier to prevent display of the information. If you do not specify any variation of the Log qualifier, the default is the current setting of the DCL verify switch. (The DCL SET VERIFY command controls the DCL verify switch.)
3 – Tables
Tables=(table-list) Specifies the table or tables for which column group entries are to be deleted, as follows: o If you specify the Tables=(table-list) qualifier, but do not specify the Column_Group qualifier, then all column group entries for the listed tables are deleted from the RDB$WORKLOAD system table. o If you specify the Tables=(table-list) qualifier, and you specify the Column_Group=(column-list) qualifier, then the workload statistics entries for the specified tables that have exactly the specified column group are deleted from the RDB$WORKLOAD system table. o If you use an asterisk (*) with the Tables qualifier (Tables=*), all tables registered in the RDB$WORKLOAD table are deleted. This allows the RDB$WORKLOAD table to be purged. If you issue an RMU Collect Optimizer_Statistics command after you have deleted a workload column group from the RDB$WORKLOAD system table, those statistics are no longer collected. The Tables=(table-list) qualifier is a required qualifier; you cannot issue an RMU Delete Optimizer_Statistics command without the Tables=(table-list) qualifier.