Re: Block-level CRC checks

> Jonah H. Harris wrote:
>> Tom Lane wrote:
>> "Harald Armin Massa" writes:
>>> WHAT should happen when corrupted data is detected?
>>
>> Same thing that happens now, ie, query fails with an error. This would
>> just be an extension of the existing validity checks done at page read
>> time.
>
> Agreed.

- however it must be understood that this may result in large portions of
the database (not otherwise corrupted) from being legitimately queried,
which may in practice simply not be acceptable; unless I misunderstand it's
significance. (so wonder if it may be necessary to identify only the logical
data within the corrupted block as being in potential error, and attempt to
limit its effect as much as possible?)

- if ZFS's effective behavior is any indication, although folks strongly
favor strong data integrity, many aren't ready to accept the consequences of
only being able to access known good data, especially if it inhibits access
to remaining most likely good data (and lacking any reasonable mechanism to
otherwise recover access to it). Sometimes ignorance is bliss.