Every night we dump and restore a 200 GB database using:
# Production, PG 9:
pg_dump DATNAME | some-irrelevant-pipe
# QA, PG 8.3:
some-irrelevant-pipe | psql -d DATNAME
I had to go for text-based backups in order to restore a dump from 9 on 8.3.
The restore is painfully and unreasonably slow. I noticed my log is full of these:
2011-05-22 08:02:47 CDT LOG: checkpoints are occurring too frequently (9 seconds apart)
2011-05-22 08:02:47 CDT HINT: Consider increasing the configuration parameter "checkpoint_segments".
2011-05-22 08:02:54 CDT LOG: checkpoints are occurring too frequently (7 seconds apart)
2011-05-22 08:02:54 CDT HINT: Consider increasing the configuration parameter "checkpoint_segments".
My question is: Is it possible that the setting of checkpoint_segments is the bottleneck? What other parameters can I tweak to speed up the process?
That machine has 4 GB RAM. Other possibly relevant settings in postgresql.conf are:
shared_buffers = 1000MB
work_mem = 200MB
maintenance_work_mem = 200MB
effective_cache_size = 2000MB
# fsync and checkpoint settings are default
Did you read this ? See specially sec 14.4.9