There is a construct that most people forget for that kind of query:
select "RT_REC_KEY", "cnxarraycolumn", "CRC" from a
except
select "RT_REC_KEY", "cnxarraycolumn", "CRC" from b;
simple.
JLL
Tom Lane wrote:
>
> "Dann Corbit" <DCorbit@connx.com> writes:
> > Yikes! Five times slower! But then I took Tom's incredibly helpful
> > suggestion to disable the sequential scan:
>
> Ideally, you shouldn't have to do that. Now that you have the correct
> indexes in place, could you show us the EXPLAIN ANALYZE output for both
> cases (enable_seqscan = on and off)?
>
> Also, you might try leaving enable_seqscan = on, and seeing how far you
> have to decrease random_page_cost to get the planner to choose
> indexscan.
>
> regards, tom lane
>
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