8.3 / 8.2.6 restore comparison

Hello,

I have been testing a migration for a week now trying to get it into a
reasonable state. This is what we have:

Restore file 220G

8.2.6 and 8.3.0 are configured identically:

shared_buffers = 8000MB
work_mem = 32MB
maintenance_work_mem = 512MB
fsync = off
full_page_writes = off
checkpoint_segments = 300
synchronous_commit = off (8.3)
wal_writer_delay = off (8.3)
autovacuum = off

8.2.6 after 2 hours has restored 41GB.
8.3.0 after 2.5 hours had restored 38GB.

Originally I was thinking that 8.2.6 was stomping 8.3. However I am
thinking that the reduction in the tuple header sizes for 8.3 means
that yes I restored 38GB, it is actually *more* data than 8.2.6. Does
that seem accurate to everyone else? If so what can we do to speed this
up? We are certainly *not* saturating the disk (16 spindles SCSI).

I am thinking the way we are going to need to do this is to have an
extended outage and write a custom script to do a concurrent dump and
load. (no in this case slony is not an option).

Sincerely,

Joshua D. Drake

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