Re: [PATCHES] wal_checksum = on (default) | off - Mailing list pgsql-hackers

From Gregory Stark
Subject Re: [PATCHES] wal_checksum = on (default) | off
Date
Msg-id 87mz4pwmx3.fsf@stark.xeocode.com
Whole thread Raw
In response to Re: [PATCHES] wal_checksum = on (default) | off  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [PATCHES] wal_checksum = on (default) | off  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
"Tom Lane" <tgl@sss.pgh.pa.us> writes:

> Gregory Stark <stark@enterprisedb.com> writes:
>> "Tom Lane" <tgl@sss.pgh.pa.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

pgsql-hackers by date:

Previous
From: Dave Cramer
Date:
Subject: Re: wal buffers documentation -errata
Next
From: Tom Lane
Date:
Subject: Re: [PATCHES] wal_checksum = on (default) | off