Re: Not Picking Index

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"Gauri Kanekar" <meetgaurikanekar@xxxxxxxxx> writes:
> I want the planner to ignore a specific index.
> I am testing some query output. For that purpose i dont want the index.
> I that possible to ignore a index by the planner.

	begin;
	drop index soandso;
	explain analyze ...;
	rollback;

Note the DROP INDEX will acquire exclusive lock on the table, so this
might not be the greatest thing to do in a production environment.
In PG 8.2 and up there is a sneakier way to do it that won't acquire
any more lock than the statement-under-test does:

	begin;
	update pg_index set indisvalid = false
	  where indexrelid = 'soandso'::regclass;
	explain analyze ...;
	rollback;

			regards, tom lane


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