Robert Haas wrote:
On Tue, Feb 1, 2011
It would be pretty hard to make autoanalyze work on such tables
without removing some of the performance benefits of having such
tables in the first place - namely, the local buffer manager. But you
could ANALYZE them by hand.
Not necessarily autoanalyze, some default rules for the situations when
stats is not there should be put in place,
like the following:
1) If there is a usable index on the temp table - use it.
2) It there isn't a usable index on the temp table and there is a join,
make the temp table the first table
in the nested loop join.
People are complaining about the optimizer not using the indexes all
over the place, there should be a way to
make the optimizer explicitly prefer the indexes, like was the case with
Oracle's venerable RBO (rules based
optimizer). RBO didn't use statistics, it had a rank of access method
and used the access method with the highest
rank of all available access methods. In practice, it translated into:
if an index exists - use it.
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