| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Martijn van Oosterhout <kleptog(at)svana(dot)org> |
| Cc: | Luca Ferrari <fluca1978(at)infinito(dot)it>, pgsql-general(at)postgresql(dot)org |
| Subject: | Re: help understanding analyze |
| Date: | 2006-12-09 17:49:46 |
| Message-ID: | 18922.1165686586@sss.pgh.pa.us |
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| Lists: | pgsql-general |
Martijn van Oosterhout <kleptog(at)svana(dot)org> writes:
> At a guess your table is not big enough to make an index worthwhile. If
> your table is only a few pages long, it's just not efficient to lookup
> an index first.
> If you post the results of EXPLAIN ANALYZE we can tell you for sure.
Actually, it would be interesting to see EXPLAIN ANALYZE for the query
both with enable_sort = on and enable_sort = off. That would show what
the planner thinks the relative costs are as well as what the true costs
are.
regards, tom lane
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