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* Postmaster getting veeeery big: SUBSTR bug
@ 1999-05-19 19:35 Eildert Groeneveld <eg@tzv.fal.de>
0 siblings, 1 reply; 2+ messages in thread
From: Eildert Groeneveld @ 1999-05-19 19:35 UTC (permalink / raw)
To: pgsql-interfaces
Never mind my initial query, it was just used for demonstration purposes.
Herouth was right in stating: "memory used for substr function" has to be
the real cause of the problem because any substr select exhibits this
behaviour:
select substr(tets,1,2) from raw_field;
This one starts the postmaster at around 3MB and finishes at 40.
Unfortunately, I have no idea about C, can someone identify the problem
and come up with a patch?
greetings
Eildert Groeneveld
=========================================
Institute for
Animal Science and Animal Behaviour
Mariensee 31535 Neustadt Germany
Tel : (49)(0)5034 871155
Fax : (49)(0)5034 92579
www : http://www.tzv.fal.de/~eg/
e-mail: eg@tzv.fal.de
=========================================
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: [INTERFACES] Postmaster getting veeeery big: SUBSTR bug
@ 1999-05-19 20:29 Tom Lane <tgl@sss.pgh.pa.us>
parent: Eildert Groeneveld <eg@tzv.fal.de>
0 siblings, 0 replies; 2+ messages in thread
From: Tom Lane @ 1999-05-19 20:29 UTC (permalink / raw)
To: eg@tzv.fal.de; +Cc: pgsql-interfaces
Eildert Groeneveld <eg@tzv.fal.de> writes:
> Herouth was right in stating: "memory used for substr function" has to be
> the real cause of the problem because any substr select exhibits this
> behaviour:
> select substr(tets,1,2) from raw_field;
> This one starts the postmaster at around 3MB and finishes at 40.
> Unfortunately, I have no idea about C, can someone identify the problem
> and come up with a patch?
The problem is well known and is on the TO-DO list: memory consumed
while evaluating expressions is not reclaimed until end of statement.
It's by no means specific to substr().
Unfortunately, fixing it is not a small amount of work (else it'd have
been done already). I'm hoping to see it fixed in 6.6.
regards, tom lane
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1999-05-19 19:35 Postmaster getting veeeery big: SUBSTR bug Eildert Groeneveld <eg@tzv.fal.de>
1999-05-19 20:29 ` Tom Lane <tgl@sss.pgh.pa.us>
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