On 2/12/2009 7:08 PM, Matthew Wakeling wrote:
On Tue, 1 Dec 2009, Jean-Michel Pouré wrote:
PostgreSQL query analyzer needs to run a couple of times before it can
rewrite and optimize the query. Make sure demand_id, id and join IDs
carry indexes.
Huh? At what point does the planner carry over previous plans and use
them to further optimise the query?
But perhaps the biggest factor here is calling a five table join a
"pretty simple query".
Some of those tables are views composed of multiple unions, too, by the
looks of things.
Doesn't the planner have some ... issues ... with estimation of row
counts on joins over unions? Or is my memory just more faulty than usual?
--
Craig Ringer
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