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* now() in loop statement
@ 2003-09-29 12:58 Kerv <keresztes_m@yahoo.com>
1970-01-01 00:00 ` Re: now() in loop statement Christoph Haller <ch@rodos.fzk.de>
2003-09-29 13:14 ` Re: now() in loop statement Tomasz Myrta <jasiek@klaster.net>
2003-09-29 13:17 ` Re: now() in loop statement Dan Langille <dan@langille.org>
0 siblings, 3 replies; 4+ messages in thread
From: Kerv @ 2003-09-29 12:58 UTC (permalink / raw)
To: pgsql-sql
Hello,
What is wrong with this function because the mytime variable contain the
same value in each iteration:
CREATE OR REPLACE FUNCTION public.time_test()
RETURNS int4 AS
'
DECLARE
count int4;
mytime timestamp;
BEGIN
count := 0;
mytime := now();
while count <= 25 loop
mytime := now();
RAISE NOTICE \'Time: %\',mytime;
count := count + 1;
end loop;
RAISE NOTICE \'Count: %\',count;
RETURN count;
END;
'
LANGUAGE 'plpgsql' VOLATILE;
the result is:
NOTICE: Time: 2003-09-29 15:52:06.745317
.
.
.
NOTICE: Time: 2003-09-29 15:52:06.745317 --same with the first value!!!
NOTICE: Count: 26
Thanks.
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: now() in loop statement
2003-09-29 12:58 now() in loop statement Kerv <keresztes_m@yahoo.com>
@ 1970-01-01 00:00 ` Christoph Haller <ch@rodos.fzk.de>
2 siblings, 0 replies; 4+ messages in thread
From: Christoph Haller @ 1970-01-01 00:00 UTC (permalink / raw)
To: keresztes_m@yahoo.com; +Cc: pgsql-sql
>
> Hello,
>
> What is wrong with this function because the mytime variable contain the
> same value in each iteration:
> CREATE OR REPLACE FUNCTION public.time_test()
> RETURNS int4 AS
> '
> DECLARE
> count int4;
> mytime timestamp;
> BEGIN
> count := 0;
> mytime := now();
> while count <= 25 loop
> mytime := now();
> RAISE NOTICE \'Time: %\',mytime;
> count := count + 1;
> end loop;
> RAISE NOTICE \'Count: %\',count;
> RETURN count;
> END;
> '
> LANGUAGE 'plpgsql' VOLATILE;
>
> the result is:
> NOTICE: Time: 2003-09-29 15:52:06.745317
> .
> .
> .
> NOTICE: Time: 2003-09-29 15:52:06.745317 --same with the first value!!!
> NOTICE: Count: 26
>
> Thanks.
>
Change
mytime := now();
to
mytime := ''now'';
and RTFM for details.
Regards, Christoph
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: now() in loop statement
2003-09-29 12:58 now() in loop statement Kerv <keresztes_m@yahoo.com>
@ 2003-09-29 13:14 ` Tomasz Myrta <jasiek@klaster.net>
2 siblings, 0 replies; 4+ messages in thread
From: Tomasz Myrta @ 2003-09-29 13:14 UTC (permalink / raw)
To: Kerv <keresztes_m@yahoo.com>; +Cc: pgsql-sql
> Hello,
>
> What is wrong with this function because the mytime variable contain the
> same value in each iteration:
Just like it should be.
now() gives you always the same value inside single transaction. If you
need time for performance tests - use "timeofday".
Regards,
Tomasz Myrta
^ permalink raw reply [nested|flat] 4+ messages in thread
* Re: now() in loop statement
2003-09-29 12:58 now() in loop statement Kerv <keresztes_m@yahoo.com>
@ 2003-09-29 13:17 ` Dan Langille <dan@langille.org>
2 siblings, 0 replies; 4+ messages in thread
From: Dan Langille @ 2003-09-29 13:17 UTC (permalink / raw)
To: Kerv <keresztes_m@yahoo.com>; +Cc: pgsql-sql
On 29 Sep 2003 at 15:58, Kerv wrote:
> What is wrong with this function because the mytime variable contain the
> same value in each iteration:
From http://www.postgresql.org/docs/7.3/static/functions-
datetime.html:
It is important to realize that CURRENT_TIMESTAMP and related
functions return the start time of the current transaction; their
values do not change during the transaction. timeofday() returns the
wall clock time and does advance during transactions.
--
Dan Langille : http://www.langille.org/
^ permalink raw reply [nested|flat] 4+ messages in thread
end of thread, other threads:[~2003-09-29 13:17 UTC | newest]
Thread overview: 4+ messages (download: mbox mbox.gz follow: Atom feed)
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2003-09-29 12:58 now() in loop statement Kerv <keresztes_m@yahoo.com>
1970-01-01 00:00 ` Christoph Haller <ch@rodos.fzk.de>
2003-09-29 13:14 ` Tomasz Myrta <jasiek@klaster.net>
2003-09-29 13:17 ` Dan Langille <dan@langille.org>
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