Re: invalid memory alloc request size

Janning Vygen <vygen(at)gmx(dot)de> writes:
> pg_dump: ERROR: invalid memory alloc request size 18446744073709551614
> pg_dump: SQL command to dump the contents of table "spieletipps" failed:
> PQendcopy() failed.

This looks more like a corrupt-data problem than anything else. Have
you tried the usual memory and disk testing programs?

> recent thread on HACKERS but sorry guys: i dont know how to produce a
> backtrace.

Time to learn ;-)

gdb /path/to/postgres_executable /path/to/core_file
gdb> bt
gdb> q

The core file will be somewhere under $PGDATA, named either "core" or
"core.nnnnn" depending on your kernel settings. If you don't see one
then it's probable that the postmaster was started under "ulimit -c 0".
Put "ulimit -c unlimited" in your postgres startup script, restart,
trigger the crash again.

It's also a good idea to look in the postmaster log to see if any
unusual messages appeared before the crash.

regards, tom lane