================= Původní zpráva =================
Od (From): "Dan Wilson" <dwilson@...>
Komu (To): firebird-support@yahoogroups.com
Kopie (Cc):
Předmět (Subject): Re: [firebird-support] Optimization Question
Datum (Date): 19. 2. 2004 18:32
==================================================

> > PLAN (SPREADACTIONTABLE ORDERED SPREADID_INDEX);
>
> This is indeed the solution, although Thomas Von Stetten showed me how to do that with the Order By clause rather than invoking the plan directly. I prefer not to impose plans directly on Firebird if I can work around it, as I know I will one day make some improvement somewhere and forget to change the direct plan override.
>
> Thanks so much for your help!
>
> Dan.

That's great! After "dummy updates", we have even "dummy orders..." Well, doesn't matter. I'm just asking myself why is the ORDER BY SPREAD_ID, ACTION_TIME necessary. Could the optimizer be tweaked to infere that if there is an equality on first n columns of an index, the n+1 column can be ordered using ORDERED read in such cases? The rule about being first column doesn't apply here because the first column of the index key is effectively out of the game.

Enjoy your fast queries :)

Jakub
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