Re: [PERFORM] planner/optimizer question

2004-05-01 Thread Jochem van Dieten
Tom Lane wrote: Manfred Koizar [EMAIL PROTECTED] writes: Yes, the visible-to-all flag would be set as a by-product of an index scan, if the heap tuple is found to be visible to all active transactions. This update is non-critical Oh really? I think you need to think harder about the transition

Re: [PERFORM] planner/optimizer question

2004-05-01 Thread Gary Doades
On 1 May 2004 at 13:18, Jochem van Dieten wrote: Yes, really :-) When a tuple is inserted the visible-to-all flag is set to false. The effect of this is that every index scan that finds this tuple has to visit the heap to verify visibility. If it turns out the tuple is not only visible

Re: [PERFORM] planner/optimizer question

2004-05-01 Thread Tom Lane
Jochem van Dieten [EMAIL PROTECTED] writes: The moment the heap tuple is updated/deleted the visible-to-all flag needs to be set to false again in all indexes. This is critical, Exactly. This gets you out of the hint-bit semantics and into a ton of interesting problems, such as race

Re: [PERFORM] Wierd context-switching issue on Xeon

2004-05-01 Thread Dave Cramer
No, don't go away and be quiet. Keep testing, it may be that under normal operation the context switching goes up but under the conditions that you were seeing the high CS it may not be as bad. As others have mentioned the real solution to this is to rewrite the buffer management so that the lock