Обсуждение: 8.5 TODO: any info on "Create dump tool for write-ahead logs..." in PITR section (1.4)?
8.5 TODO: any info on "Create dump tool for write-ahead logs..." in PITR section (1.4)?
От
"shakahshakah@gmail.com"
Дата:
Can anyone elaborate (or point me to some additional info) on the 8.5 TODO item in the "Point-In-Time Recover (PITR) section (1.4)": Create dump tool for write-ahead logs for use in determining transaction id for point-in-time recovery This is useful for checking PITR recovery. I poked around a bit and found some code that "walks" the WAL logs (in src/backend/access/transam/xlog.c, I think) and I could probably figure out how to display a WAL log file contents, but I'm hoping someone can provide some context as to what issue this TODO item is trying to address (i.e., what output would be useful).
Hi, On Sat, Oct 3, 2009 at 7:30 AM, shakahshakah@gmail.com <shakahshakah@gmail.com> wrote: > Can anyone elaborate (or point me to some additional info) on the 8.5 > TODO item in the "Point-In-Time Recover (PITR) section (1.4)": > Create dump tool for write-ahead logs for use in determining > transaction id for point-in-time recovery > This is useful for checking PITR recovery. > > I poked around a bit and found some code that "walks" the WAL logs (in > src/backend/access/transam/xlog.c, I think) and I could probably > figure out how to display a WAL log file contents, but I'm hoping > someone can provide some context as to what issue this TODO item is > trying to address (i.e., what output would be useful). I think that xlogdump (http://xlogviewer.projects.postgresql.org/) is the first step to address that TODO item. Though I'm not sure if the xlogdump project is still active. Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center
Re: 8.5 TODO: any info on "Create dump tool for write-ahead logs..." in PITR section (1.4)?
От
"Jonah H. Harris"
Дата:
On Sun, Oct 4, 2009 at 10:28 PM, Fujii Masao <masao.fujii@gmail.com> wrote:
I believe it has been dead for quite awhile now. Though, Tom may still maintain his own xlogdump.
I think that xlogdump (http://xlogviewer.projects.postgresql.org/) is
the first step to address that TODO item. Though I'm not sure if the
xlogdump project is still active.
I believe it has been dead for quite awhile now. Though, Tom may still maintain his own xlogdump.
--
Jonah H. Harris, Senior DBA
myYearbook.com
Re: 8.5 TODO: any info on "Create dump tool for write-ahead logs..." in PITR section (1.4)?
От
Heikki Linnakangas
Дата:
shakahshakah@gmail.com wrote: > Can anyone elaborate (or point me to some additional info) on the 8.5 > TODO item in the "Point-In-Time Recover (PITR) section (1.4)": > Create dump tool for write-ahead logs for use in determining > transaction id for point-in-time recovery > This is useful for checking PITR recovery. > > I poked around a bit and found some code that "walks" the WAL logs (in > src/backend/access/transam/xlog.c, I think) and I could probably > figure out how to display a WAL log file contents, but I'm hoping > someone can provide some context as to what issue this TODO item is > trying to address (i.e., what output would be useful). That TODO item is a lot less important after we have Hot Standby. It contains functions that allow you to pause and continue WAL replay, and step through the WAL one transaction at a time. It won't let you go backwards, though, so it won't completely replace a tool like xlogdump, which you can use to look into the WAL before applying it. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com
Hi, On Tue, Oct 6, 2009 at 7:47 AM, Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> wrote: > That TODO item is a lot less important after we have Hot Standby. It > contains functions that allow you to pause and continue WAL replay, and > step through the WAL one transaction at a time. I don't think this is practical for PITR purpose, since applying one transaction at a time up to the recovery target point might take very long time. So the tool to quickly determine the recovery target point is necessary even after we have HS, I think. Am I missing something? Regards, -- Fujii Masao NIPPON TELEGRAPH AND TELEPHONE CORPORATION NTT Open Source Software Center
Re: 8.5 TODO: any info on "Create dump tool for write-ahead logs..." in PITR section (1.4)?
От
Euler Taveira de Oliveira
Дата:
Fujii Masao escreveu: > On Tue, Oct 6, 2009 at 7:47 AM, Heikki Linnakangas > <heikki.linnakangas@enterprisedb.com> wrote: >> That TODO item is a lot less important after we have Hot Standby. It >> contains functions that allow you to pause and continue WAL replay, and >> step through the WAL one transaction at a time. > > I don't think this is practical for PITR purpose, since applying one transaction > at a time up to the recovery target point might take very long time. So the tool > to quickly determine the recovery target point is necessary even after we have > HS, I think. Am I missing something? > No. BTW, I have an unpublished version here that I didn't commit because I need to clean it up. :( -- Euler Taveira de Oliveira http://www.timbira.com/