Re: Online verification of checksums - Mailing list pgsql-hackers

From Fabien COELHO
Subject Re: Online verification of checksums
Date
Msg-id alpine.DEB.2.21.1903040702230.8095@lancre
Whole thread Raw
In response to Re: Online verification of checksums  (Michael Paquier <michael@paquier.xyz>)
List pgsql-hackers
Bonjour Michaël,

>> I agree that having a server function (extension?) to do a full checksum
>> verification, possibly bandwidth-controlled, would be a good thing. However
>> it would have side effects, such as interfering deeply with the server page
>> cache, which may or may not be desirable.
>
> In what is that different from VACUUM or a sequential scan?

Scrubbing would read all files, not only relation data? I'm unsure about 
what does VACUUM, but it is probably pretty similar.

> It is possible to use buffer ring replacement strategies in such cases 
> using the normal clock-sweep algorithm, so that scanning a range of 
> pages does not really impact Postgres shared buffer cache.

Good! I did not know that there was an existing strategy to avoid filling 
the cache.

-- 
Fabien.

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