Обсуждение: WAL file naming convention
Hi
Is is safe to assume that the unix ls command will return WAL files in the same sequence as postgres creates them.
e.g will ls <wal-file-folder> return files in the order that postgres created them
As PostgreSQL numbers WALs sequentially, as long as your ls command by default orders listings by filename, then Yes. Or you could list by the last modified date/time should give the same effect.
Andy
From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Sriram Dandapani
Sent: Saturday, 25 March, 2006 12:30 am
To: pgsql-admin@postgresql.org
Subject: [ADMIN] WAL file naming convention
Hi
Is is safe to assume that the unix ls command will return WAL files in the same sequence as postgres creates them.
e.g will ls <wal-file-folder> return files in the order that postgres created them
On Sat, Mar 25, 2006 at 05:51:13PM -0000, Andy Shellam wrote: > As PostgreSQL numbers WALs sequentially, as long as your ls command by > default orders listings by filename, then Yes. Or you could list by the > last modified date/time should give the same effect. But note that the order it creates them in doesn't have much meaning, because it can re-use them. So if you want to know anything about actual current order of usage the filename is meaningless. > _____ > > From: pgsql-admin-owner@postgresql.org > [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Sriram Dandapani > Sent: Saturday, 25 March, 2006 12:30 am > To: pgsql-admin@postgresql.org > Subject: [ADMIN] WAL file naming convention > > > > Hi > > > > Is is safe to assume that the unix ls command will return WAL files in the > same sequence as postgres creates them. > > > > e.g will ls <wal-file-folder> return files in the order that postgres > created them > > !DSPAM:14,44248f2235041511888239! -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
I was referring to the logs in the archive folder specified when WAL archiving is turned on...not the pg_xlog folder. I assume postgres will not use the logs in the archive folder -----Original Message----- From: Jim C. Nasby [mailto:jnasby@pervasive.com] Sent: Monday, March 27, 2006 2:35 AM To: Andy Shellam Cc: Sriram Dandapani; pgsql-admin@postgresql.org Subject: Re: [ADMIN] WAL file naming convention On Sat, Mar 25, 2006 at 05:51:13PM -0000, Andy Shellam wrote: > As PostgreSQL numbers WALs sequentially, as long as your ls command by > default orders listings by filename, then Yes. Or you could list by the > last modified date/time should give the same effect. But note that the order it creates them in doesn't have much meaning, because it can re-use them. So if you want to know anything about actual current order of usage the filename is meaningless. > _____ > > From: pgsql-admin-owner@postgresql.org > [mailto:pgsql-admin-owner@postgresql.org] On Behalf Of Sriram Dandapani > Sent: Saturday, 25 March, 2006 12:30 am > To: pgsql-admin@postgresql.org > Subject: [ADMIN] WAL file naming convention > > > > Hi > > > > Is is safe to assume that the unix ls command will return WAL files in the > same sequence as postgres creates them. > > > > e.g will ls <wal-file-folder> return files in the order that postgres > created them > > !DSPAM:14,44248f2235041511888239! -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
On Mon, Mar 27, 2006 at 09:28:43AM -0800, Sriram Dandapani wrote: > I was referring to the logs in the archive folder specified when WAL > archiving is turned on...not the pg_xlog folder. > > I assume postgres will not use the logs in the archive folder Correct. And I believe if you have PITR enabled PostgreSQL also won't re-use WAL names, though I'm not positive on that one. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
Jim C. Nasby wrote: > On Mon, Mar 27, 2006 at 09:28:43AM -0800, Sriram Dandapani wrote: > > I was referring to the logs in the archive folder specified when WAL > > archiving is turned on...not the pg_xlog folder. > > > > I assume postgres will not use the logs in the archive folder > > Correct. And I believe if you have PITR enabled PostgreSQL also won't > re-use WAL names, though I'm not positive on that one. PostgreSQL never reuses WAL _names_ (since initdb), it only reuses WAL files by renaming. -- Bruce Momjian http://candle.pha.pa.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +