Re: Fwd: index corruption in PG 8.3.13

Excerpts from Nikhil Sontakke's message of mié mar 09 20:28:19 -0300 2011:

> While I rummage around the code more, does anyone have any theories on
> the below?
>
> "Other peculiarity in the index file is that we found a lot of zeroed
> out pages. Blocks from #279 to #518 are all completely zeroed out
> without any signs of even a page header. Any ideas on how we can get
> so many zeroed out blocks? Apart from the extend code path, I fail to
> see any other. And this is an unusually large number of zero pages"

Well, if you see the root block child pointers, they go to pages
2, 4-277,522-524. So pages 278 to 521 seem unused for some reason,
which is rather strange. But apparently only page 523 is zeroed and
shouldn't be.

It seems hard to believe that there would be 245 unsuccessful attempts
at extending the file.

Page 522 is suspect too ... why does it have a single item? Note its
LSN is very close to the one on page 521.

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Álvaro Herrera <alvherre(at)commandprompt(dot)com>
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