Arnau a écrit :
Hi all,
I've got a DB in production that is bigger than 2GB that dumping it
takes more than 12 hours. I have a new server to replace this old one
where I have restore the DB's dump. The problem is I can't afford to
have the server out of business for so long, so I need your advice about
how you'd do this dump/restore. The big amount of data is placed in two
tables (statistics data), so I was thinking in dump/restore all except
this two tables and once the server is running again I'd dump/restore
this data. The problem is I don't know how exactly do this.
Any suggestion?
Thanks
Jeff answer made me check what were the configuration parameters.
That machine had the default ones, so I tweaked a bit them and now I
got a dump in about 2 hours. To dump the DB I'm using the following
command:
/usr/bin/pg_dump -o -b -Fc $db > $backup_file
And as result I got a file of 2.2GB. The improvement has been quite
big but still very far from the 10-15 minutes that Jeff says or the
Thomas'3 minutes.
The version I'm running is a 7.4.2 and the postgresql.conf
parameters are the following:
# - Memory -
shared_buffers = 10000 # min 16, at least max_connections*2,
8KB each
sort_mem = 10240 # min 64, size in KB
vacuum_mem = 81920 # min 1024, size in KB
# - Free Space Map -
max_fsm_pages = 40000 # min max_fsm_relations*16, 6 bytes each
max_fsm_relations = 2000 # min 100, ~50 bytes each
Any suggestions the even reduce more the dump period?
Thank you very much.
To reduce dump period I suggest you to use the unix pipes :
pgdumps $PSOPTIONS | psql $database
I make always like this as it 's a lot faster
Olivier
