I'm running PG 9.3.4 on CentOS 6.4 and noted that backing up my database takes much longer than restoring it.

That seems counter-intuitive to me because it seems like reading from a database should generally be faster than writing to it.

I have a database that pg_database_size reports as 18GB, and resulting dump is about 13GB in 27 files (split creates them as 512MB).

A pg_dump backup -- with most of the data stored as large objects -- takes about 5 hours.

But restoring that dump takes about 2 hours. So it's taking 2.5 times longer to back it up than to restore it.

My backup script runs vacuumlo, then vacuum, then analyze, then pg_dump --format=c --oids $DB

I actually push pg_dump output through gzip, gpg and split on 512MB files, but they shouldn't matter too much I figure as I have to run cat, gpg and gunzip before pg_restore. In fact, my restore should have been at a disadvantage because I used '-v' and showed the results to my ssh term over the Internet which includes a line for each LOID, and the postgresql.conf had 'ddl' logging on (which I suspect I can turn off in future restores to speed things up a bit).

Is there something that might be wrong about my configuration that the backup is slower than the restore?

Thanks,
David



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