Re: unlogged tables vs. GIST - Mailing list pgsql-hackers

From Heikki Linnakangas
Subject Re: unlogged tables vs. GIST
Date
Msg-id 4D0BBEAA.7010008@enterprisedb.com
Whole thread Raw
In response to Re: unlogged tables vs. GIST  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: unlogged tables vs. GIST  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On 17.12.2010 21:32, Robert Haas wrote:
> I guess the question is whether it's right to conflate "table is
> unlogged" with "LSN is fake".  It's not immediately obvious to me that
> those concepts are isomorphic, although though the reverse isn't
> obvious to me either.

The buffer manager only needs to know if it has to flush the WAL before 
writing the page to disk. The flag just means that the buffer manager 
never needs to do that for this buffer. You're still free to store a 
real LSN there if you want to, it just won't cause any WAL flushes.

--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com


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