Re: [HACKERS] [PATCHES] wal_checksum = on (default) | off

"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:

> Gregory Stark <stark(at)enterprisedb(dot)com> writes:
>> "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> writes:
>>> Pretty much not happening; or are you volunteering to fix every part of
>>> the system to tolerate injections of inserted data anywhere in a stored
>>> datum?
>
>> I was thinking to do it at a low level as the xlog records are prepared to be
>> written to the filesystem and as the data is being read from disk. I haven't
>> read that code yet to see where to inject it but I understand there's already
>> a copy happening and it could be done there.
>
> You understand wrong ... a tuple sitting on disk is normally read
> directly from the shared buffer, and I don't think we want to pay for
> copying it.

"xlog records"

--
Gregory Stark
EnterpriseDB http://www.enterprisedb.com