Subject | RE: [IBO] TIMESTAMP question |
---|---|
Author | Don Schoeman |
Post date | 2004-12-10T13:30:03Z |
Hehehe, that makes a big difference :) I just read this in the Firebird
Generator Guide (http://www.fingerbird.de/generatorguide_body.htm):
"So if you would feed a column with a Dialect 3 Generator, and you would
insert 1000 rows per second, it would take roundabout 300 million years
before it rolls over. As it is pretty unlikely mankind will still walk on
this planet by then (and still use Firebird databases), that's nothing to be
really worried about :-)
If you'd do the same with a Dialect 1 (32bit) Generator, it would roll over
after 25 DAYS!!! and that is indeed something to have an eye on. 2^31 is a
lot, but then again not that much depending on the situation..."
Regards,
Don Schoeman
-----Original Message-----
From: Helen Borrie [mailto:helebor@...]
Sent: 10 December 2004 02:46 PM
To: IBObjects@yahoogroups.com
Subject: RE: [IBO] TIMESTAMP question
At 02:35 PM 10/12/2004 +0200, you wrote:
9,223,372,036,854,775,807. That's enough for several lifetimes; but if
you live long enough, yes, it will roll over at that point and start
generating duplicates.
:-)
Helen
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Generator Guide (http://www.fingerbird.de/generatorguide_body.htm):
"So if you would feed a column with a Dialect 3 Generator, and you would
insert 1000 rows per second, it would take roundabout 300 million years
before it rolls over. As it is pretty unlikely mankind will still walk on
this planet by then (and still use Firebird databases), that's nothing to be
really worried about :-)
If you'd do the same with a Dialect 1 (32bit) Generator, it would roll over
after 25 DAYS!!! and that is indeed something to have an eye on. 2^31 is a
lot, but then again not that much depending on the situation..."
Regards,
Don Schoeman
-----Original Message-----
From: Helen Borrie [mailto:helebor@...]
Sent: 10 December 2004 02:46 PM
To: IBObjects@yahoogroups.com
Subject: RE: [IBO] TIMESTAMP question
At 02:35 PM 10/12/2004 +0200, you wrote:
>What happens when a generator reaches it's top limit (which I assume is anfactor
>Integer value), does it wrap to 0 or to it's negative limit? With the speed
>that recording could potentially occur at, this is quite an important
>to consider before using a generator to generate a primary key for thisA generator is a 64-bit integer (BigInt) so it will reach its top limit at
>table.
9,223,372,036,854,775,807. That's enough for several lifetimes; but if
you live long enough, yes, it will roll over at that point and start
generating duplicates.
:-)
Helen
Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.