Re: Improving compressibility of WAL files

Aidan Van Dyk wrote:
> * Richard Huxton <dev@archonet.com> [090109 12:22]:
> 
>>> Yeah: the archiver process doesn't have that information available.
> 
>> Am I being really dim here - why isn't the first record in the WAL file
>> a fixed-length record containing e.g. txid_start, time_start, txid_end,
>> time_end, length? Write it once when you start using the file and once
>> when it's finished.
> 
> It would break the WAL "write-block/sync-block" forward only progress of
> the xlog, which avoids the whole torn-page problem that the heap has.

I thought that only applied when the filesystem page-size was less than
the data we were writing?

--  Richard Huxton Archonet Ltd