Stefan Kaltenbrunner wrote:
Tom Lane wrote:
"Joshua D. Drake" <[EMAIL PROTECTED]> writes:
Yeah, that... is beyond my abilities. Well reading it is anyway. I can
provide any information people want though. Tom? Greg? Andrew? Somebody?
What information do you want from me to help you track this down?
The vmstat output you showed before said user CPU time was only around
12%, which seems to destroy Luke's thesis that data conversion time
is the problem. IIRC we were speculating that data was being written
in a pattern that required a lot of seeking thus ruining throughput,
but we didn't have any hard evidence of that. Did you do the strace'ing
I suggested?
Joshua said this is an 8 core box - so 12% would about equal to one core
being maxed out completely CPU wise which seems to correlate fairly well
with my experience (COPY being CPU bottlenecked on fast hardware without
any real culprit to find in profiles).
Right. I mentioned previously that I was able to gain what could be
considered barely acceptable performance break breaking up a custom dump
into multiple pieces and restoring across multiple connections.
I have Alvaro reviewing the strace. I can't post it without some cleansing.
Sincerely,
Joshua D. Drake
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