When I do an EXPLAIN ANALYZE on the above query, the result is:

Seq Scan on city_alias (cost=0.00..59282.31 rows=2 width=42) (actual time=73.369..3330.281 rows=407 loops=1)
   Filter: ((name)::text ~~ '%FRANCISCO'::text)
Total runtime: 3330.524 ms
(3 rows)


this is a query that our system needs to do a LOT. Is there any way to improve the performance on this either with changes to our query or by configuring the database deployment? We have an index on city_name but when using the % operator on the front of the query string postgresql can't use the index .

Of course not. There really is now way to make your literal query above fast. You could try making a functional index on the reverse() of the string and querying for the reverse() of 'francisco'.

Or, if you want a general full text index, you should absolutely be using contrib/tsearch2.

Chris

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