Jon Nelson <jnelson+pgsql@jamponi.net> writes:
> The following query results in a crash, ultimately due to the process
> running out of memory:
> create table blah as select md5(generate_series(1,50000000)::text) as a;
The behavior looks the same to me in either 9.3 or HEAD: it does consume a
lotta memory (about 7GB) but eventually finishes. If it's crashing for
you, you probably need to look at your system-level configuration,
particularly the per-process memory ulimit level vs. available RAM/swap
and whether the dreaded OOM killer is enabled.
The reason it's eating so much memory is you've got a profligate SRF in
the SELECT's targetlist. Try it as, eg,
create table blah as select md5(g::text) as a from generate_series(1,50000000) g;
While it's be nice to not have SRFs in the targetlist be a memory problem,
it's not an easy thing to do, and I doubt anyone is going to look very
hard for a fix for what is basically a deprecated feature.
regards, tom lane
