Re: Index Scans become Seq Scans after VACUUM ANALYSE

Reading all of this discussion lately about how the planner seems to
prefer seqscan's in alot of places where indexes would be better starts
making me wonder if some of the assumptions or cals made to figure costs
are wrong...

Anyone have any ideas?

Louis-David Mitterrand wrote:

>On Tue, Apr 16, 2002 at 10:41:57AM -0400, Tom Lane wrote:
>
>>Louis-David Mitterrand <vindex(at)apartia(dot)org> writes:
>>
>>>While trying to optimise a query I found that running VACUUM ANALYSE
>>>changed all the Index Scans to Seq Scans and that the only way to revert
>>>to Index Scans was the add "enable_seqscan = 0" in postgresql.conf.
>>>
>>EXPLAIN ANALYZE output would be more interesting than just EXPLAIN.
>>Also, what does the pg_stats view show for these tables?
>>
>
>Thanks, pg_stats output is rather big so I attached it in a separate
>file. Here are the EXPLAIN ANALYZE ouputs:
>
>... SNIP ...
>
>