Re: page corruption on 8.3+ that makes it to standby

On Tue, 2010-07-27 at 21:23 -0700, Jeff Davis wrote:

> Both potential fixes attached and both appear to work.
> 
> fix1 -- Only call PageSetLSN/TLI inside log_newpage() and
> heap_xlog_newpage() if the page is not zeroed.
> 
> fix2 -- Don't call log_newpage() at all if the page is not zeroed.
> 
> Please review. I don't have a strong opinion about which one should be
> applied.

ISTM we should just fix an uninitialized page first, using code from
VACUUM similar to

  if (PageIsNew(page))
  {
    ereport(WARNING,
	(errmsg("relation \"%s\" page %u is uninitialized --- fixing",
						relname, blkno)));
    PageInit(page, BufferGetPageSize(buf), 0);
  }

then continue as before.

We definitely shouldn't do anything that leaves standby different to
primary.

-- 
 Simon Riggs           www.2ndQuadrant.com
 PostgreSQL Development, 24x7 Support, Training and Services