Re: out of memory during query execution

DANTE ALEXANDRA wrote:
> 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.

Too bad, I may have been able to determine what had happened with the
gcc build.

> 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 ?

It is quite likely that the out of memory errors are due to your use of
the default 32-bit memory model. In that model, a single 256MB memory
segment contains your heap, stack, thread stacks, and other per-process,
non-shared-library data. Switching to 64-bit would stop the errors if
this is true. It is also possible to adjust the amount of space
available to a 32-bit process' heap with the -bmaxdata linker option,
but the largest heap size that I would consider safe with 32-bit is 2GB
and comes with the cost of reducing the amount of shared memory
available to the process.

Setting OBJECT_MODE to 64 before the ./configure and gmake should result
in a 64-bit build, but I don't have a copy of IBM's compiler to test
with. I would be interested in seeing the errors output by the 64-bit
gcc build if another build is attempted.

--
Seneca Cunningham
scunning(at)ca(dot)afilias(dot)info