On Wednesday 19 Feb 2003 12:24 am, you wrote:
> Shridhar,
>
> I must disagree with "that's is an OS's job".
> OSs try to be generic. With databases, we know more about the data
> structure.
>
> If a large table could be split (partitioned) based on specific key, we
> could expect huge improvements for agregates queries for example when
> that key is involved.
Well, you can create a base table and inherit four or five of them. But that
does not solve the problem really, because postgresql as such does not
support different disk storage area that granularly.
> Also, DBA must be able to place table on different file systems. They
> know more about the application than the OS does.
Certainly. But the advantage will not be visible unless you put it on a disk
that is on separate IDE or SCSI channel. Now that you have a large database,
are you using more than one SCSI channel? Otherwise just putting on different
disks will not help as much.
> Even Postgresql has to be told to perform vaccum and analyze.
> If the OS had enough intelligence we could trust it to do a good job,
> but until then ...
Partially true. Postgresql could have done vacuum at runtime at the cost od
performance. So developers delegated the task to admin.
Looking for a solution in problem, the real benefits won't be visible unless
you put it on a different disk channel. Otherwise RAID is your best bait now
as OS can handle it intelligently and it enhances the IO bandwidth immensely.
Other than that you can not do much with postgresql right now.
Shridhar
