Tom Lane wrote:
Zdenek Kotala <[EMAIL PROTECTED]> writes:
I would like to make following modification:
1) Add ReadBuffer_noerror (recommend me better name) function which will
accept damaged page without Error. This page will be marked as corrupted
and when ReadBuffer will touch this page then it will be handled in
standard way.
This seems like a pretty horrid idea. Bad pages shouldn't be allowed to
get into shared buffers in the first place. Why not have the checking
logic operate outside shared buffers?
It currently works outside the shared buffers, but I afraid about
collision due to parallel read and write access on one block. I'm not
sure if parallel write(8k) and read(8k) is synchronized by kernel/fs or
not. If not it should generates false positive results. If yes than I'm
happy :-) with outside processing.
3) Add PageHeaderIsValid check also for write operation
In production it should catch problem with memory or software bugs. In
development it should catch memory overwriting.
Is there any evidence whatsoever to demonstrate that this is worth the
cycles it will eat?
Alex from clickware tries this modification to catch their problem with
random damaged database. But, I don't have any result yet.
Zdenek
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