Thread: now() time off
Earlier this week when I logged into my database, I just so happened to notice that the value for now() was six hours off of the time reported by the operating system when using the date command from the command line. How is this possible? I rebooted the server and the problem magically went away. I am quite certain that I didn't modify anything in the database that should cause this problem. It turns out that that the now() time has been off for some time, and resulted in quite a bit of corrupted data. What exactly should I do in the future to keep this from happening, or where should I look for clues? John
On Wed, 2006-02-22 at 16:36, John McCawley wrote: > Earlier this week when I logged into my database, I just so happened to > notice that the value for now() was six hours off of the time reported > by the operating system when using the date command from the command > line. How is this possible? I rebooted the server and the problem > magically went away. I am quite certain that I didn't modify anything > in the database that should cause this problem. It turns out that that > the now() time has been off for some time, and resulted in quite a bit > of corrupted data. What exactly should I do in the future to keep this > from happening, or where should I look for clues? Sounds like a time zone issue. I'd start looking there.
On Wed, Feb 22, 2006 at 04:46:35PM -0600, Scott Marlowe wrote: > On Wed, 2006-02-22 at 16:36, John McCawley wrote: > > Earlier this week when I logged into my database, I just so happened to > > notice that the value for now() was six hours off of the time reported > > by the operating system when using the date command from the command > > line. How is this possible? I rebooted the server and the problem > > magically went away. I am quite certain that I didn't modify anything > > in the database that should cause this problem. It turns out that that > > the now() time has been off for some time, and resulted in quite a bit > > of corrupted data. What exactly should I do in the future to keep this > > from happening, or where should I look for clues? > > Sounds like a time zone issue. I'd start looking there. I've been bitten by this before as well. I'd be in favor of adding an option such that postmaster would refuse to start if TZ was something other than UTC; I'd much rather that then have a bunch of data get screwed up... -- 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 Wed, Feb 22, 2006 at 06:35:55PM -0600, Jim C. Nasby wrote: > On Wed, Feb 22, 2006 at 04:46:35PM -0600, Scott Marlowe wrote: > > Sounds like a time zone issue. I'd start looking there. > > I've been bitten by this before as well. I'd be in favor of adding an > option such that postmaster would refuse to start if TZ was something > other than UTC; I'd much rather that then have a bunch of data get > screwed up... Alternativly you could just set the "timezone" parameter in the postgresql configuration... Have a nice day, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a > tool for doing 5% of the work and then sitting around waiting for someone > else to do the other 95% so you can sue them.
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On Thu, Feb 23, 2006 at 12:41:38PM +0100, Martijn van Oosterhout wrote: > On Wed, Feb 22, 2006 at 06:35:55PM -0600, Jim C. Nasby wrote: > > On Wed, Feb 22, 2006 at 04:46:35PM -0600, Scott Marlowe wrote: > > > Sounds like a time zone issue. I'd start looking there. > > > > I've been bitten by this before as well. I'd be in favor of adding an > > option such that postmaster would refuse to start if TZ was something > > other than UTC; I'd much rather that then have a bunch of data get > > screwed up... > > Alternativly you could just set the "timezone" parameter in the > postgresql configuration... Wow, didn't know that was there... was it added fairly recently or have I just been blind? -- 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 Thu, Feb 23, 2006 at 04:21:19PM -0600, Jim C. Nasby wrote: > On Thu, Feb 23, 2006 at 12:41:38PM +0100, Martijn van Oosterhout wrote: > > Alternativly you could just set the "timezone" parameter in the > > postgresql configuration... > > Wow, didn't know that was there... was it added fairly recently or have > I just been blind? http://www.postgresql.org/docs/7.3/interactive/release-7-3.html "Add configuration variables datestyle and timezone (Tom)" -- Michael Fuhr
On Thu, Feb 23, 2006 at 03:49:50PM -0700, Michael Fuhr wrote: > On Thu, Feb 23, 2006 at 04:21:19PM -0600, Jim C. Nasby wrote: > > On Thu, Feb 23, 2006 at 12:41:38PM +0100, Martijn van Oosterhout wrote: > > > Alternativly you could just set the "timezone" parameter in the > > > postgresql configuration... > > > > Wow, didn't know that was there... was it added fairly recently or have > > I just been blind? > > http://www.postgresql.org/docs/7.3/interactive/release-7-3.html > > "Add configuration variables datestyle and timezone (Tom)" Whew. I started on 7.2, so I have a bit of an excuse. :) -- 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