Re: [GENERAL] Disappearing Records

2005-11-02 Thread Venki
) Regards Venki ---Original Message---   From: Martijn van Oosterhout Date: 11/02/05 17:47:26 To: Venki Cc: pgsql-general@postgresql.org Subject: Re: [GENERAL] Disappearing Records   On Wed, Nov 02, 2005 at 05:00:35PM +0530, Venki wrote: > >The really nasty thing about it is that becau

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Harald Fuchs
In article <[EMAIL PROTECTED]>, Douglas McNaught <[EMAIL PROTECTED]> writes: > Rory Browne <[EMAIL PROTECTED]> writes: >> select u.username, g.groupname from users u, groups g where u.group_id=g.id >> (assuming users are in exactly one group) >> >> If the group_id field in the users table was cor

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Martijn van Oosterhout
On Wed, Nov 02, 2005 at 10:28:56AM -0500, Tom Lane wrote: > Looking at the code, I think that actually a regular, non-FREEZE VACUUM > would do the "right thing" for tuples up to about 1 billion xacts past > wrap, which is probably enough. So the answer may be "just VACUUM". > I'm still too lazy to

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Tom Lane
Martijn van Oosterhout writes: > On Wed, Nov 02, 2005 at 09:46:38AM -0500, Tom Lane wrote: >> You sure about that? I think VACUUM just tests for "committed or not". >> >> I'm too lazy to set up a test case, but it's possible that VACUUM FREEZE >> would resurrect wrapped-around tuples, or could b

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Martijn van Oosterhout
On Wed, Nov 02, 2005 at 09:46:38AM -0500, Tom Lane wrote: > Martijn van Oosterhout writes: > > The really nasty thing about it is that because the records are now > > considered really old, as soon as you do run VACUUM it'll start > > removing the rows you want to save... > > You sure about that?

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Tom Lane
Martijn van Oosterhout writes: > The really nasty thing about it is that because the records are now > considered really old, as soon as you do run VACUUM it'll start > removing the rows you want to save... You sure about that? I think VACUUM just tests for "committed or not". I'm too lazy to s

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Douglas McNaught
Rory Browne <[EMAIL PROTECTED]> writes: > select u.username, g.groupname from users u, groups g where u.group_id=g.id > (assuming users are in exactly one group) > > If the group_id field in the users table was corrupted, and set to a > value that isn't in the groups table, then that view wouldn't

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Rory Browne
Thanks guys for your suggestions, but the problem turned out to be my lack of experience(with PostgreSQL), combined with a bug in our PHP Code. Coming from a MySQL background, I assumed that if you "select x from y", then y would be the name of a table. It turned out that in the case that y was ac

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Martijn van Oosterhout
On Wed, Nov 02, 2005 at 05:00:35PM +0530, Venki wrote: > >The really nasty thing about it is that because the records are now > >considered really old, as soon as you do run VACUUM it'll start > >removing the rows you want to save... > So does this mean that when we do a vacuum for the first time

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Venki
Am I wrong in this?     regards Venki    ---Original Message---   From: Martijn van Oosterhout Date: 11/02/05 17:09:45 To: John Sidney-Woollett Cc: Venki; pgsql-general@postgresql.org Subject: Re: [GENERAL] Disappearing Records   On Wed, Nov 02, 2005 at 07:40:29AM +, John Sidney-Woolle

Re: [GENERAL] Disappearing Records

2005-11-02 Thread Martijn van Oosterhout
On Wed, Nov 02, 2005 at 07:40:29AM +, John Sidney-Woollett wrote: > If you have suffered data loss for this reason, then you'll need to get > help from the developers to see whether it can be recovered, or what you > can do to reconstruct the data. The really nasty thing about it is that bec

Re: [GENERAL] Disappearing Records

2005-11-01 Thread John Sidney-Woollett
nced this problem disappearinf records. regards Venki ---Original Message--- From: Tom Lane Date: 11/01/05 20:30:51 To: Rory Browne Cc: pgsql-general@postgresql.org Subject: Re: [GENERAL] Disappearing Records Rory Browne <[EMAIL PROTECTED]> writes: What is th

Re: [GENERAL] Disappearing Records

2005-11-01 Thread Venki
disappearinf records.     regards Venki ---Original Message---   From: Tom Lane Date: 11/01/05 20:30:51 To: Rory Browne Cc: pgsql-general@postgresql.org Subject: Re: [GENERAL] Disappearing Records   Rory Browne <[EMAIL PROTECTED]> writes: > What is the first thing you would do, when you

Re: [GENERAL] Disappearing Records

2005-11-01 Thread Tom Lane
Rory Browne <[EMAIL PROTECTED]> writes: > What is the first thing you would do, when you find that your system > has been losing information? Information is there at one stage, and > later it's not. Has your system been used long enough that it could be subject to transaction ID wraparound?

Re: [GENERAL] Disappearing Records

2005-11-01 Thread Terry Fielder
Do you have any cascading deletes that could be doing this by performing a delete on a different table and cascading to the table in question? Terry Rory Browne wrote: Hi all What is the first thing you would do, when you find that your system has been losing information? Information is there

[GENERAL] Disappearing Records

2005-11-01 Thread Rory Browne
Hi all What is the first thing you would do, when you find that your system has been losing information? Information is there at one stage, and later it's not. I tried checking the logs, but there isn't a delete or drop there anywhere, nor anything else that seems relevent. I tried googling for v