Thread: what are clog and xlog?

what are clog and xlog?

From

flyusa2010 fly

Date:

05 December 2010, 13:08:20

Hi, folks,

I'm a newbie to postgres. I'm confused with xlog and clog.

To my initial understanding, xlog is the periodic checkpoint log for data, while clog is for commit log (very unclear for me ...)

Thanks!

Re: what are clog and xlog?

From

"Kevin Grittner"

Date:

05 December 2010, 13:30:44

flyusa2010 fly  wrote:
> clog is for commit log (very unclear for me ...)
It is an important part of tracking tuple visibility.
You might want to start with this page:
http://wiki.postgresql.org/wiki/Hint_Bits
-Kevin