Horton

Re: WAL format changes

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

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From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Andres Freund <andres@2ndquadrant.com>
Cc: pgsql-hackers@postgresql.org, Robert Haas <robertmhaas@gmail.com>
Date: 2012-06-18T18:32:54Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Update pgindent install instructions and update typedef list.

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