Heikki Linnakangas <[EMAIL PROTECTED]> writes:
> On further thought, there is one workload where removing the non-LRU 
> part would be counterproductive:

> If you have a system with a very bursty transaction rate, it's possible 
> that when it's time for a checkpoint, there hasn't been any WAL logged 
> activity since last checkpoint, so we skip it. When that happens, the 
> buffer cache might still be full of dirty pages, because of hint bit 
> updates. That still isn't a problem on it's own, but if you then do a 
> huge batch update, you have to flush those dirty pages at that point. It 
> would be better to trickle flush those dirty pages during the idle period.

But wouldn't the LRU-based scan accomplish that?

                        regards, tom lane

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