Re: Query runs fast or slow

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

felix-accts-pgsql(at)crowfix(dot)com writes:
> EXPLAIN ANALYZE doesn't show the slow timing
> because it requires values, not $n placeholders,

To analyze the plan used for a parameterized query, try

	PREPARE foo(...) AS SELECT ... $n ...

	EXPLAIN ANALYZE EXECUTE foo(...)

But I already know what you're going to find: the planner's estimates
for the range query are not going to be very good when it has no idea
what the range bounds are.  This is a situation where it may be best
to absorb the hit of re-planning each time instead of using a generic
parameterized plan.

			regards, tom lane