On Dec 10, 2008, at 4:08 PM, Tom Lane wrote:
Richard Yen <dba@xxxxxxxxxxx> writes:
Is there any way to tune this so that for the common last names,
the query
run time doesn't jump from <1s to >300s?
Well, as near as I can tell there's factor of a couple hundred
difference between the frequencies of 'smith' and 'smithers', so
you shouldn't really expect similar runtimes for the two cases.
Having said that, I still think you should try to index both first
and last name. Also I wonder whether the index on owner is worth
having at all. It definitely doesn't seem worthwhile to index the
entries with owner = -1, since there are so many; so maybe you could
make it a partial index that excludes those entries, in order to
prevent
the planner from trying to use it for this case.
Created the 2-col index, and the query runs much faster on all
permutations.
Thanks much for all your help,
--Richard
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