On 18.06.2012 21:13, Andres Freund wrote:
On Monday, June 18, 2012 08:08:14 PM Heikki Linnakangas wrote:
The page header contains an XLogRecPtr (LSN), so if we change it we'll
have to deal with pg_upgrade. I guess we could still keep XLogRecPtr
around as the on-disk representation, and convert between the 64-bit
integer and XLogRecPtr in PageGetLSN/PageSetLSN. I can try that out -
many xlog calculations would admittedly be simpler if it was an uint64.
I am out of my depth here, not having read any of the relevant code, but
couldn't we simply replace the lsn from disk with InvalidXLogRecPtr without
marking the page dirty?
There is the valid argument that you would loose some information when pages
with hint bits are written out again, but on the other hand you would also
gain the information that it was a hint-bit write...
Sorry, I don't understand that. Where would you "replace the LSN from
disk with InvalidXLogRecPtr" ? (and no, it probably won't work ;-) )
--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
