Re: Replication identifiers, take 4 - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Replication identifiers, take 4
Date
Msg-id CANP8+jKhb=ahExxmDhFjO+p_-gEOXAY6moytOZSeYczsySGWGQ@mail.gmail.com
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In response to Re: Replication identifiers, take 4  (Heikki Linnakangas <hlinnaka@iki.fi>)
Responses Re: Replication identifiers, take 4
List pgsql-hackers
On 17 April 2015 at 18:12, Heikki Linnakangas <hlinnaka@iki.fi> wrote:
On 04/17/2015 12:04 PM, Simon Riggs wrote:
On 17 April 2015 at 09:54, Andres Freund <andres@anarazel.de> wrote:

Hrmpf. Says the person that used a lot of padding, without much
discussion, for the WAL level infrastructure making pg_rewind more
maintainable.

Sounds bad. What padding are we talking about?

In the new WAL format, the data chunks are stored unaligned, without padding, to save space. The new format is quite different to the old one, so it's not straightforward to compare how much that saved. 

The key point here is the whole WAL format was changed to accommodate a minor requirement for one utility. Please notice that nobody tried to stop you doing that.
 
The changes Andres is requesting have a very significant effect on a major new facility. Perhaps there is concern that it is an external utility?

If we can trust Heikki to include code into core that was written externally then I think we can do the same for Andres.

I think its time to stop the padding discussion and commit something useful. We need this.

--
Simon Riggs                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

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