Hannu Krosing kirjutas N, 04.12.2003 kell 23:01: > > > Where should I be looking in the code? > > Try to find where the modified query is tested for. It's probably be > inside the optimizer, as index scan + no sort is not always faster than > seq scan + sort, as shown by the same query after vacuum analyze (on an > empty table)
OTOH, it may be that all combinations of sort and index and where are not watched in the optimiser proper at all (too compliaced and/or too costly), but a keyhole optimiser is run over its resulting "best" plan to remove redundant sorts (but it misses combinations of sort and where like the one in your example) --------------- Hannu ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])