[sorry if this was previously asked: list searches seem to be down]
I'm using pg_dump to take a full backup of my database using a compressed format: $ pg_dump -Fc my_db > /backup/my_db.dmp
It produces a 6 GB file whereas the pgdata uses only 5 GB of disk space: $ ls -l /backup -rw-r--r-- 6592715242 my_db.dmp $ du -b /data 5372269196 /data
How could it be? As far as I know, dumps should be smaller than filesystem datafile since they do not store indexes, etc.
Database contains about one-hundred-thousands binary images, some of which may be already compressed. So i tried the --compress=0 option but this produces a dump that does not fit on my disk (more than 11 GB). I'm using postgres 8.1.2 on RHEL4.
So, what can I do to diagnose the problem? Thanks in advance,
