Re: out of memory during query execution - Mailing list pgsql-general

Hello,

Thank you for your answer.
The person is charge of building PostGreSQL 8.1.0 has done a 32 bit
build and has used the "cc_r" compiler.
This person does not succeed to build PostGreSQL 8.1.0 with "gcc" and 64
bits. Unfortunatly, I don't have the errors or the logs of the 64 bits
build and I can't tell you what error occurs.

The build done was realized in 32 bits, with the cc_r compiler.
To build POstGreSQL, a rpm was done and the ".spec" file contained the
following instructions :
export OBJECT_MODE=32
./configure CC=/usr/vac/bin/cc_r CFLAGS="-O2 -qmaxmem=-1 -qsrcmsg
-qlargepage" --enable-thread-safety
--without-readline --prefix=%{buildroot}%{prefix}
gmake -j 4
unset OBJECT_MODE

Do you think that my problems of "out of memory" are due to the 32 bits
build ?
Do you think that I must build PostGreSQL wih 64 bits to solve this error ?

Thank you for your help.
Regards,
Alexandra DANTE


Chris Browne a écrit :

>ALEXANDRA.DANTE@BULL.NET (DANTE ALEXANDRA) writes:
>
>
>>I am a PostGreSQL newbie. I work with the 8.1.0 release on AIX 5.3,
>>with 300GB of datas.
>>Some of the queries launched on this database finish with an "*out of
>>memory*". The queries which have failed contain a lot of join (between
>>6 tables), sub-select and aggregate. For these queries, the log file
>>contains :
>>psql:Q9.sql:40: ERROR:  out of memory
>>DETAIL:  Failed on request of size 148.
>>
>>On the server used, I got 3GB of memory and 1 CPU.
>>The settings specified in the "postgresql.conf" are :
>># - Memory -
>>shared_buffers = 12288                 #temp_buffers = 1000
>>#max_prepared_transactions = 5       work_mem = 65536
>>maintenance_work_mem = 262144         max_stack_depth = 24574
>>
>>Are some of these values false?
>>Is the "out of memory" error due to smaller memory available ?
>>Has somenone ever seen this problem ?
>>
>>
>
>We have seen this problem...
>
>It's *probably* related to the memory model you're using.
>
>I have thus far evaded *fully* understanding the details (and hope
>that can persist!), but here are some of the things to consider:
>
>- By default, AIX really prefers to build 32 bit binaries
>
>- The sorta-hacks that IBM put in place on library segmentation (and
>this stuff is quite ghastly) mean that any backend will likely have
>quite a bit less than 2GB of even theoretically-available memory space.
>
>The problem is probably that the memory model is throttling you to
>*WAY* less than 2GB of memory.
>
>You may want to try a 64 bit build.  With GCC, this requires something
>like the following ./configure incantation...
>
>  CC="gcc -maix64" LDFLAGS="-Wl,-bbigtoc" ./configure
>
>