Ühel kenal päeval, E, 2006-11-13 kell 13:42, kirjutas Csaba Nagy: > [snip] > > IMHO *most* UPDATEs occur on non-indexed fields. [snip] > > > > If my assumption is badly wrong on that then perhaps HOT would not be > > useful after all. If we find that the majority of UPDATEs meet the HOT > > pre-conditions, then I would continue to advocate it. > > Just to confirm that the scenario is valid: our application has almost > all it's updates affecting only non-indexed columns. There are a few > exceptions, but the vast majority is non-indexed, and that holds to the > execution frequency too, not just for the count of tables/queries.
One interesting case which should also be considered is conditional indexes: create index on payments(payment_id) where status = 'waiting'; here the payment_id is not changed when processing the payment, but when status is changed to 'processed' it still should be removed from the index. How would this interact with HOT ? -- ---------------- Hannu Krosing Database Architect Skype Technologies OÜ Akadeemia tee 21 F, Tallinn, 12618, Estonia Skype me: callto:hkrosing Get Skype for free: http://www.skype.com ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
