Re: log chunking broken with large queries under load

Andrew Dunstan <andrew@dunslane.net> writes:
> On 04/02/2012 12:00 PM, Tom Lane wrote:
>> This seems like it isn't actually fixing the problem, only pushing out
>> the onset of trouble a bit.  Should we not replace the fixed-size array
>> with a dynamic data structure?

> But maybe your're right. If we do that and stick with my two-dimensional 
> scheme to keep the number of probes per chunk down, we'd need to reorg 
> the array every time we increased it. That might be a bit messy, but 
> might be ok. Or maybe linearly searching an array of several hundred 
> slots for our pid for every log chunk that comes in would be fast enough.

You could do something like having a list of pending chunks for each
value of (pid mod 256).  The length of each such list ought to be plenty
short under ordinary circumstances.
        regards, tom lane