Out of curiosity, does anyone have any idea what the ratio of actual datasize to backup size is if I use the custom format with -Z 0 compression or the tar format?
On Wed, 2006-06-14 at 09:47, John E. Vincent wrote: > -- this is the third time I've tried sending this and I never saw it get > through to the list. Sorry if multiple copies show up. > > Hi all,
BUNCHES SNIPPED
> work_mem = 1048576 ( I know this is high but you should see some of our > sorts and aggregates)
Ummm. That's REALLY high. You might want to consider lowering the global value here, and then crank it up on a case by case basis, like during nighttime report generation. Just one or two queries could theoretically run your machine out of memory right now. Just put a "set work_mem=1000000" in your script before the big query runs.
> We're inserting around 3mil rows a night if you count staging, info, dim > and fact tables. The vacuum issue is a whole other problem but right now > I'm concerned about just the backup on the current hardware. > > I've got some space to burn so I could go to an uncompressed backup and > compress it later during the day.
That's exactly what we do. We just do a normal backup, and have a script that gzips anything in the backup directory that doesn't end in .gz... If you've got space to burn, as you say, then use it at least a few days to see how it affects backup speeds.
Seeing as how you're CPU bound, most likely the problem is just the compressed backup.