Re: pg_xlog becomes extremely large during CREATE INDEX

"Jeffrey W. Baker" <jwbaker@acm.org> writes:
> On Thu, 2004-05-13 at 21:00, Tom Lane wrote:
>> I tried this locally, and what I see happening is that a checkpoint
>> process starts shortly after the CREATE INDEX begins whomping out the
>> index data --- but it doesn't finish until after the CREATE INDEX does.
>> AFAICS there is not any sort of locking problem, it's just that the
>> CREATE INDEX is chewing all the I/O bandwidth.  If we could get some
>> more checkpoints pushed through then the xlog would get truncated, but
>> it's not happening.
>>
>> I'm running this on a development machine with an ok CPU and junk
>> consumer-grade-IDE disk drive, so lack of I/O bandwidth is hardly
>> surprising; can anyone confirm the observation on better hardware?

> We're running it on some pretty manly hardware (dual opterons, 8gb main
> memory, 4-way SATA RAIDs), so it happens on both ends of the spectrum.

What I wanted to know was whether you see a checkpoint process
persisting throughout the write-the-index phase of the CREATE INDEX.
There probably will be one at pretty nearly all times, but is it
always the same one (same PID)?

            regards, tom lane