Heikki Linnakangas wrote:

> - The signaling between RequestCheckpoint and bgwriter is a bit tricky. 
> Bgwriter now needs to deal immediate checkpoint requests, like those 
> coming from explicit CHECKPOINT or CREATE DATABASE commands, differently 
> from those triggered by checkpoint_segments. I'm afraid there might be 
> race conditions when a CHECKPOINT is issued at the same instant as 
> checkpoint_segments triggers one. What might happen then is that the 
> checkpoint is performed lazily, spreading the writes, and the CHECKPOINT 
> command has to wait for that to finish which might take a long time. I 
> have not been able to convince myself neither that the race condition 
> exists or that it doesn't.

Isn't it just a matter of having a flag to tell whether the checkpoint
should be quick or spread out, and have a command set the flag if a
checkpoint is already running?

Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support

---------------------------(end of broadcast)---------------------------
TIP 6: explain analyze is your friend

Reply via email to