On Sun, Aug 29, 2004 at 06:03:43PM -0400, Tom Lane wrote:
> The expression "now() - something" is not a constant, so the planner
> is faced with "timestampfield > unknownvalue". Its default assumption
> about the number of rows that will match is much too high to make an
> indexscan look profitable (from memory, I think it guesses that about
> a third of the table will match...).
Out of curiosity, does the subselect query I presented earlier in the thread
count as "a constant"? It gives the correct query plan, but this could of
course just be correct by accident...
/* Steinar */
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