Thread: clog files

clog files

From
fatih ozturk
Date:
Hi
I want to ask some part of a question that is asked before by "Duan Ligong" and not answered

"
Could you explain how the clog files work roughly?
(What is inside of the clog files? when and how the new clog files
are created? when and in what case the old files are deleted
or rotated? how does postgresql regard a file is old enough to be
deleted? Does Vacuum will definitely cause deleting of old files
and creating of new clog files?)
"

Thansk for your interest

Re: clog files

From
Bruce Momjian
Date:
fatih ozturk wrote:
> Hi
> I want to ask some part of a question that is asked before by "Duan Ligong" and not answered
>
> "
> Could you explain how the clog files work roughly?
>
> (What is inside of the clog files? when and how the new clog files
>
> are created? when and in what case the old files are deleted
>
> or rotated? how does postgresql regard a file is old enough to be
>
> deleted? Does Vacuum will definitely cause deleting of old files
>
> and creating of new clog files?)
> "
>
> Thansk for your interest

There is a slide here of the clog file internals:

    http://momjian.us/main/writings/pgsql/internalpics.pdf

clog is rotated on its own by our code and there is no user maintenence
required.

You have to look in our C code for the rest of the answers.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +