Re: Hi- How frequently Postgres Poll for trigger file

On 01.12.2010 13:27, aaliya zarrin wrote:
> I want to know how frequently postgres search for trigger file to switch
> over.

In 9.0, every 100ms while streaming replication is active and connected. 
5 seconds otherwise. In current git master branch, it's always 5 s.

> Can this switch over time be reduced?

Not without hacking the sources and compiling.

Although, on many platforms, Linux included I believe, sending a signal 
to the startup process should wake it up from the sleep and make it 
check the trigger file immediately. "pg_ctl reload" for example should 
do it. So if ýou send a signal to the startup process immediately after 
creating the trigger file, it should take notice sooner.

> Plz let me know where postgres poll for trigger file. I could find it out in
> "backend/access/trans/xlog.c" ? am i right?

Yes. search for callers of CheckForStandbyTrigger() function.


--   Heikki Linnakangas  EnterpriseDB   http://www.enterprisedb.com