Problem with dumping zabbix database - Postgres

[pietro54]

Hello,
I got problem with dumping my database,
Database is quite big, around 220gb

My problem looks like:

-bash-4.1$ pg_dump zabbix | /usr/local/bin/lbzip2 -n 20 -9 > /backup/database/zabbix.dump.`date +%Y%m%d`.gz
pg_dump: SQL command failed
pg_dump: Error message from server: ERROR: invalid memory alloc request size 1492224378
pg_dump: The command was: COPY public.trends_uint (itemid, clock, num, value_min, value_avg, value_max) TO stdout;

I changed ulimit -l unlimited but this isent change enything.
I was still observing memory load:
watch -n 1 "free -m" and memory load was 2,6Gb

What can be the reason?

My system:
Redhat 6 x64
24Gb ram
Postgres 9.1.8
Zabbix 2.0.4

[pietro54]

Case is solved.

I dont know how, but data was damaged in database.

I deleted damaged data from trends_uint and this helps.