Re: [HACKERS] page is uninitialized --- fixing

2009-06-10 Thread Simon Riggs
On Tue, 2009-06-09 at 17:28 -0400, Tom Lane wrote: Is there any particular reason to suppose that the empty pages appeared during a crash recovery? Have you read through md.c? I seem to recall there are some slightly squirrelly choices made there about segment-extension behavior. Maybe

[HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Simon Riggs
A couple of people in recent years have had a problem with page X is uninitialised -- fixing messages. I have a case now with 569357 consecutive pages that required fixing in pg_attribute. We looked at pages by hand and they really are uninitialised, but otherwise what we would expect for size,

Re: [HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Tom Lane
Simon Riggs si...@2ndquadrant.com writes: A couple of people in recent years have had a problem with page X is uninitialised -- fixing messages. I have a case now with 569357 consecutive pages that required fixing in pg_attribute. We looked at pages by hand and they really are uninitialised,

Re: [HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Simon Riggs
On Tue, 2009-06-09 at 13:54 -0400, Tom Lane wrote: Simon Riggs si...@2ndquadrant.com writes: A couple of people in recent years have had a problem with page X is uninitialised -- fixing messages. I have a case now with 569357 consecutive pages that required fixing in pg_attribute. We

Re: [HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Tom Lane
Simon Riggs si...@2ndquadrant.com writes: A couple of people in recent years have had a problem with page X is uninitialised -- fixing messages. I have a case now with 569357 consecutive pages that required fixing in pg_attribute. We looked at pages by hand and they really are uninitialised,

Re: [HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Simon Riggs
On Tue, 2009-06-09 at 16:17 -0400, Tom Lane wrote: Simon Riggs si...@2ndquadrant.com writes: A couple of people in recent years have had a problem with page X is uninitialised -- fixing messages. I have a case now with 569357 consecutive pages that required fixing in pg_attribute. We

Re: [HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Tom Lane
Simon Riggs si...@2ndquadrant.com writes: A corrupt record of a block number would do this in XLogReadBuffer() if we had full page writes enabled. But it would have to be corrupt between setting it correctly and the CRC check on the WAL record. Which is a fairly small window of believability.

Re: [HACKERS] page is uninitialized --- fixing

2009-06-09 Thread Simon Riggs
On Tue, 2009-06-09 at 17:28 -0400, Tom Lane wrote: Simon Riggs si...@2ndquadrant.com writes: A corrupt record of a block number would do this in XLogReadBuffer() if we had full page writes enabled. But it would have to be corrupt between setting it correctly and the CRC check on the WAL