On Tuesday 20 February 2007 01:53, Amos Shapira wrote: > On 19/02/07, Tzahi Fadida <[EMAIL PROTECTED]> wrote: > > On Monday 19 February 2007 05:26, Amos Shapira wrote: > > > Hello, > > > > > > Is it possible to configure PostgresQL to use raw disk partition, like > > > Oracle does? > > > If not - is there any recommendation for favourite filesystem type to > > > > use? > > > > Most certainly not. > > PostgreSQL relies on the OS and FileSystems it inhabits for all I/O > > operations. Raw partition are not worth the extra effort anycase on an OS > > such as linux which is already efficient with files and extents of those > > files. If you want you can use XFS to increase efficiency at the expense > > of > > Well I didn't expect Postgres to do the actual SCSI calls to the disk, but > I sort of guess that since all the database needs from the OS is a bunch of > disk blocks and the database "file" can be usually pre-allocated, it might > be possible to do away from the complexity (and time penalty) of a FS which > assumes that files have to be created/resized/removed all the time. That's > the way Oracle databases at least used to be configured for many years > (taking the update from Ira into account).
In PostgreSQL they don't even do the caching (more or less), they let the OS to do it. This is a common question and the claim of the PostgreSQL dev community is that the added benefit of a raw fs will be negligable. I for one believe it because many of them uses oracle also. Not to mention PostgreSQL is more or less compatible in syntax with oracle. I also can tell you that with recent stable versions 8+ and recent kernels you can probably achieve almost raw fs capabilities by using certain file options (which they do). They also use techniques as back writings etc... This thing is very advanced. > > more chance for data loss in case of a crash since it has a large caching > > > mechanisms. You can also use raid to increase performance. Additionally > > you > > may try to put the transactions log, which is the bottleneck in > > databases, on > > a ram memory that is backed by a battery. I think i saw a battery PCI > > card at > > asus for 50$. Add 128mb ram and you are good to go. > > That (battey-backed RAM) sounds like a good tip. Will keep it around. > Thanks. If you have more specific details to help Google for such a product > I'll appreciate to hear them. Check out these sites, i think these are the real thing: http://www.anandtech.com/tradeshows/showdoc.aspx?i=2431&p=5 http://www.cenatek.com/ However, also remember to periodically back up your stuff to the HD. I trust batteries only so far. :) > > Cheers, > > --Amos -- Regards, Tzahi. -- Tzahi Fadida Blog: http://tzahi.blogsite.org | Home Site: http://tzahi.webhop.info WARNING TO SPAMMERS: see at http://members.lycos.co.uk/my2nis/spamwarning.html ================================================================To unsubscribe, send mail to [EMAIL PROTECTED] with the word "unsubscribe" in the message body, e.g., run the command echo unsubscribe | mail [EMAIL PROTECTED]
