On Aug 15, 2006, at 12:26 , Peter Eisentraut wrote:
AgentM wrote:
I've always found it odd that database didn't determine which
statistics are the most interesting from the queries themselves.
The overhead of doing that on the fly is probably prohibitive. More
explicit profiling support could be helpful, but that would seem a lot
more complicated than, say, a compiler profiling tool that merely has
to sort out the branch predictions.
Couldn't the session be explicitly transferred into a special
analysis mode? Explain analyze could run on every query implicitly
and point out time and row count discrepancies as HINTs. Multi-column
joins, for example, could be pointed out and display whether or not
there are related indexes.
Then, I imagine, I would regularly run all my app's prepared queries
through this analysis mode to see what I could improve. Who knows the
database better than itself?
-M
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TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match