Hi all...i would like to know how can i collect statistics on only one of a table's partions... Could someone suggest me the better way to find out a resolution to my doubt?...Thank for your interesting!!!
Hi karmakoma, if a table is partitioned, there's always a column named PARTITION, which returns the partition number.
You can "collect stats on table column partition", it's much faster than "collect stats on table column partitioning_column" and it still helps the optimizer, bacause he knows about number of partitions with data.
If a partition is empty it would be left out from the read process even if its not eliminated directly by the query.
But this facility is available only from V2R6 and i guess its not available in V2R5.
Collecting stats on the system derived column Partition is faster because rather than reading all the base table rows, it usually just scans the cylinder index for that PPI table and collects information from that.