Re: [PERFORM] VACUUM FREEZE output more than double input

2007-12-17 Thread Kevin Grittner
>>> On Fri, Dec 14, 2007 at 5:59 PM, in message <[EMAIL PROTECTED]>, Tom Lane <[EMAIL PROTECTED]> wrote: > "Kevin Grittner" <[EMAIL PROTECTED]> writes: >> Why double writes per read, plus massive writes at checkpoint? > > The double writes aren't surprising: freezing has to be WAL-logged, > and

Re: [PERFORM] VACUUM FREEZE output more than double input

2007-12-14 Thread Tom Lane
"Kevin Grittner" <[EMAIL PROTECTED]> writes: > Why double writes per read, plus massive writes at checkpoint? The double writes aren't surprising: freezing has to be WAL-logged, and the odds are that each page hasn't been touched since the last checkpoint, so the WAL log will include a complete pa