Re: Improving compressibility of WAL files

Tom Lane wrote:
> "Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
>> Greg Smith <gsmith@gregsmith.com> wrote: 
>>> I thought at one point that the direction this was going toward was to 
>>> provide the size of the WAL file as a parameter you can use in the 
>>> archive_command:
>  
>> Hard to beat for performance.  I thought there was some technical
>> snag.
>  
> 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.

--  Richard Huxton Archonet Ltd