Re: [HACKERS] Re: [BUGS] General Bug Report: palloc fails with lots of ANDs and ORs

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От Vadim B. Mikheev
Тема Re: [HACKERS] Re: [BUGS] General Bug Report: palloc fails with lots of ANDs and ORs
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Msg-id 34BD91D2.8A0985F1@sable.krasnoyarsk.su
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Ответ на Re: [BUGS] General Bug Report: palloc fails with lots of ANDs and ORs  (Bruce Momjian <maillist@candle.pha.pa.us>)
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Bruce Momjian wrote:
>
> > Bruce,
> >
> > I did some homework.   Here is what I have.   The default max data segment size on our (AIX 4.1.4) box is around
130000kbytes. 
> >
> > I put together a query which put me just past the threshold of the palloc "out of memory error".  It is as follows:
> >
> > create table outlet (
> >     number int,
> >     name varchar(30),
> >     ...
> > }
> >
> > create unique index outlet_key on outlet using btree (number);
> >
> > select count(*) from outlet
> > where
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1) or
> >     (number = 1 and number = 1 and number = 1);
> >
...
> >
>
> Wow, looks like a bug.  Vadim, why would this happen?  I got the same
> palloc failure message here, and there is NO data in the table.

This is bug in optimizer - try to EXPLAIN query...
I have no time to fix it now - could return to this after Feb 1.

Vadim

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