Re: WAL FILES

----- Original Message -----

From: Khan, Mahmood Ahram

To: Ashish Karalkar

Sent: Friday, May 18, 2007 10:49 AM

Subject: RE: [ADMIN] WAL FILES

One thing which I observed in PostgreSQL WAL files archiving is that it archives 16mb file at a given timeout period.

Example I gave 25 seconds, it is generating each 16mb file after every 25 sec. If there are no transaction & entries also.

With this performance will also be down & space will also be utilized. Instead it should make archives when there is data, not on time basis.

For this I think I have to make timeout parameter 0. Means disabling the force feature for archiving.

 

 

Thanks & Best Regards

 

M.AHRAM KHAN 

---

From: Ashish Karalkar [mailto:ashish.karalkar@info-spectrum.com]
Sent: Friday, May 18, 2007 10:25 AM
To: Khan, Mahmood Ahram
Cc: pgsql-admin@postgresql.org
Subject: Re: [ADMIN] WAL FILES

 

take care to inclue a parameter in the copy command that will make sure the archived WAL will not be overwritten

 

 

for your reference(on Linux)

 

 

    "It is important that the archive command return zero exit status if and only if it succeeded. Upon getting a zero result, PostgreSQL will assume that the WAL segment file has been successfully archived, and will remove or recycle it. However, a nonzero status tells PostgreSQL that the file was not archived; it will try again periodically until it succeeds.

The archive command should generally be designed to refuse to overwrite any pre-existing archive file. This is an important safety feature to preserve the integrity of your archive in case of administrator error (such as sending the output of two different servers to the same archive directory). It is advisable to test your proposed archive command to ensure that it indeed does not overwrite an existing file, and that it returns nonzero status in this case. We have found that cp -i does this correctly on some platforms but not others. If the chosen command does not itself handle this case correctly, you should add a command to test for pre-existence of the archive file. "

 

----- Original Message -----

From: Khan, Mahmood Ahram

To: Ashish Karalkar

Sent: Friday, May 18, 2007 9:07 AM

Subject: RE: [ADMIN] WAL FILES

 

Thanks Ashish,

 

Its working fine now. And I set the archive timeout parameter to 25. (i,e 25 seconds).

 

So Thanks once again.

 

 

 

 

Thanks & Best Regards

 

M.AHRAM KHAN 

---

From: Ashish Karalkar [mailto:ashish.karalkar@info-spectrum.com]
Sent: Thursday, May 17, 2007 6:26 PM
To: Khan, Mahmood Ahram
Subject: Re: [ADMIN] WAL FILES

 

I think u should try

 

archive_command = ' copy  %p d:\archive\%f '

 

 

I hope this should work.

I am not  windows user but still i think.

Please let me know if it works.

 

set the archive timeout para to lower value to see it works or nt immediately.

 

With regards

Ashish...

----- Original Message -----

From: Khan, Mahmood Ahram

To: pgsql-admin@postgresql.org

Sent: Thursday, May 17, 2007 4:42 PM

Subject: [ADMIN] WAL FILES

 

 

Hi All,

 

I am archiving PostgreSQL Database. I want to copy all my WAL files from pg_xlogs folder to d:\archive

I am using PostgreSQL 8.2 on Windows XP.

And my archive_command looks like this      ( archive_command  copy c:\Program Files\PostgreSQL\8.2\data\pg_xlog d:\archive\  )

But it is loading the files in pg_xlogs folder itself. So Can anybody have idea about this.

 

 

Thanks & Regards

 

M.AHRAM KHAN