Re: Adding new flags to XLogRecord - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Adding new flags to XLogRecord
Date
Msg-id 16391.1221741538@sss.pgh.pa.us
Whole thread Raw
In response to Re: Adding new flags to XLogRecord  (Simon Riggs <simon@2ndQuadrant.com>)
Responses Re: Adding new flags to XLogRecord  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: Adding new flags to XLogRecord  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
Simon Riggs <simon@2ndQuadrant.com> writes:
> On Thu, 2008-09-18 at 12:40 +0100, Greg Stark wrote:
>> Why bit just add a new bitfield for flags if we need them? I'm usually  
>> the one worried about data density so perhaps I should be on the other  
>> side of the fence here but I'm not sure. The conventional wisdom is  
>> that wal bandwidth is not a major issue.

> In some cases, but my wish is also to minimise WAL volume as much as
> possible.

I'm with Greg on this one: baroque bit-squeezing schemes are a bad idea.

You still haven't answered the question of what you need four more bits
for (and why four more is all that anyone will ever need --- unless you
can prove that, we might as well just add another flag field).
        regards, tom lane


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