=?ISO-8859-1?Q?Gunnlaugur_=DE=F3r_Briem?= <gunnlau...@gmail.com> writes:
> I did this:
> CREATE VIEW unionview AS
> SELECT col, otherstuff FROM (heavy subquery)
> WHERE col BETWEEN 1 AND 3
> UNION ALL
> SELECT col, otherstuff FROM (another heavy subquery)
> WHERE col BETWEEN 4 AND 6;
> hoping that the planner could use the WHERE conditions (like it would use
> check constraints on tables) to exclude one of the subqueries, for a query
> like:
> SELECT * FROM unionview WHERE col=2;
> But it doesn't. (In PostgreSQL 8.4.5, at least.)
Works for me in 8.4.8. Do you have constraint_exclusion set to ON?
regards, tom lane
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