Oh, and there's another value for the case we're polling the archive, not streaming from master. Search for "5" in XLogPageRead function to catch them all.
On 02.12.2010 08:21, Heikki Linnakangas wrote:
It's the 5000000L argument in the WaitLatch call. It's expressed in microseconds.
On 02.12.2010 06:39, aaliya zarrin wrote:
Where this 5 Seconds time is defined in the code ???
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 ıou 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.