Query tuning/planner method configuration v16

These configuration parameters are used for planner method configuration.


Parameter type: Boolean

Default value: false

Range: {true | false}

Minimum scope of effect: Per session

When value changes take effect: Immediate

Required authorization to activate: Session user

Allows the query planner to early prune partitioned tables. Early pruning means that the query planner can "prune" (that is, ignore) partitions that aren't searched in a query before generating query plans. This setting helps improve performance because it prevents generating query plans of partitions that aren't searched.

Conversely, late pruning means that the query planner prunes partitions after generating query plans for each partition. The constraint_exclusion configuration parameter controls late pruning.

The ability to early prune depends on the nature of the query in the WHERE clause. You can use early pruning in only simple queries with constraints like WHERE column = literal, for example, WHERE deptno = 10.

Don't use early pruning for more complex queries such as WHERE column = expression, for example, WHERE deptno = 10 + 5.

This parameter is deprecated from version 15 and later. Use enable_partition_pruning instead.