So, through no fault of our own, we find ourselves in the World Cup Quarter Final, playing Portugal tomorrow afternoon. The prize is a Semi-Final match against the winner of Brazil v. France. It’s a bit of a mystery how England have managed to get even this far, because despite having watched all their games, they never seemed to play terribly well; not exactly badly, just nothing that struck me as all that impressive.
Edit, after The Match:: Penalties. Again. Bugger.
And on a totally unrelated note, I’ve been learning even more about PostgreSQL recently, in my attempt to draw up a suitable specification for a high performance database server. Different RAID levels, different numbers of disks, how to configure the PostgreSQL process to make the best of the available resources and so on, as well as good strategies for indexing of tables. This database server is going to take quite aheavy load, so I need to get it right. Fingers crossed…
Depends on how the data is used as to total optimal config, but basically…
data on a raid10
indexes on a raid 1
loads of ram
15k disks…with a hardware raid controller, or maybe two if you can afford two disk arrays.
you’ll have to ‘play’ with the indexes and sql once you got the data..
I’ve had shoddy sql go from a 5 day run time for reports to 1/2 day by merely tuning the SQL, not even touching anything else….
Permalinkdata on a raid10, indexes on a raid 1
Does keeping the indexes on a separate system really help? The above implies at least six disks too (at least 4 for a RAID-10 and at least 2 for RAID-1)…
Won’t be a problem getting lots of RAM and I’m thinking about two controllers anyway.
Permalinkyes, esp if the writes are faily heavy.
Doing an index rebuild every so often works well too.
If you can a 14 spindle disk array it#ll help.
I know it’s a massive waste of space, but seeing as though you can’t get 2GB disk anymore……it’s the physical spindles that count…
If our ERP could have it’s indexes on a separate raid 1 set I’d have done that, but the layout forces it into the same dir as the DB.
Also think about backup and transaction logs. Where will they be in relation to the DB. Again if you get the transactions logs onto separate disks this will help enormously too.
PermalinkUseful tips: I’ll see whether it works with the budget I’m gonna get or not 😉
PermalinkLooks like PostgreSQL keeps all its database in a single location too, doesn’t seem to be any non-trivial way to break it up.
So, a single large RAID-10 it is then 🙂
Permalinkerr you sure about that…
http://www.postgresql.org/docs/8.0/interactive/sql-createtablespace.html
PermalinkOh, *that’s* what tablespaces are.
I’ll have to read about that, then 🙂
PermalinkSpaces (files) to put tables in…
Having the indexes on separate tablespaces is a good idea anyway, whether or not they are on different spindles/RAID arrays is down to the application….ie try both ways and see how the DB performs.
If you’ve got lots of writes it’s best have them on separate RAID sets…
BUT first of all tune the SQL, then look at disk layout…
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