can anybody explain me what is partition pruning?????
I would suggest that it is to do with dropping unused partitions in a table. Before doing this though, you should be careful to identify whether or not the indexes you have on the partitions are local or global indexes. If the indexes are global to the partitioned table, after the partition is dropped, the associated table index will marked 'unusable', until it is rebuilt.
Anyone else with thoughts on this?
OCP 8i, 9i DBA
Partition pruning is the method that the optimizer uses to to exclude partitions from the results of a query. See http://otn.oracle.com/docs/products/...part.htm#98260 for details.
Partition pruning is the abliliy of the CBO to only use the partition which holds the data being queried.
Say you partitioned a table into q1_2001, q2_2001 and q3_2001 and you are interested in data of february 2001, only partition q1_2001 data will be read.
The q2_2001 and q3_2001 partititions will be pruned.
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