Re: WAL question

Evgeny Gridasov wrote:
> Hello.
>
> So, what happens if I set checkpoint_segments and checkpoint_timeout very high,
> and, shared_buffers to a very low value?
> Will PostgreSQL force a checkpoint when it has not enough memory in shared_buffers for some new "un-checkpointed"
data? 

It won't force a checkpoint -- it will release memory by causing
individual buffer evictions.  (What checkpoint does is evicting all
buffers in one go, but backends can cause a buffer to be evicted if they
need it for something else).

--
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.