Re: Filesystem a factor in DB transaction speed ?

Forrest Cicogni wrote:

> While it is true that there exists file systems outperforming NTFS, the
> point is nearly moot. Oracle depends less upon underlying file systems
> than other programs, thanks to efficiently designed contiguous data files
> and read/write buffering. File systems, fast or not, are the single
> greatest source of bottlenecking, and the object of a well designed Oracle
> database is to nearly eliminate disk I/O all together. Therefore, focus on
> tuning and designing, and rely less upon finding faster hardware to make
> up for poor implementations. The old adage still applies: "Fast computers
> breed lazy programmers."
>
>
>

Forrest:

I'm not sure you are 100% correct here.
Are you saying that 'sidestepping' the issue of buffered reads and writes by means of an abstaction layer above the filesystem actually increases efficiency ? That makes no sense logically ! May I back up my claim with a reference to the www.namesys.com website (ReiserFS' home page):

Section "Why aggregate small objects at the File System Level ?"

"Performance: It is most commonly the case that when one layers one file system on top of another the performance is substantially reduced, and Structured Storage is not an exception to this general rule. Reiserfs, which does not attempt to delegate the small object problem to a layer above, avoids this performance loss. I have heard it suggested by some that this layering avoids the performance loss from syncing on file close as many file systems do. I suggest that this is adding an error to an error rather than fixing it.

Let me make clear that I believe those who write such layers above the file system do not do so out of stupidity. I know of at least one company at which a solution that layers small object storage above the file system exists because the file system developers refused to listen to the non-file system group's description of its needs, and the file system group had to be sidestepped in generating the solution. "

I do trust Mr. Reiser's programming and mathematical background insofar as that he would not make this statement if it were untrue. From what I can tell, with Oracle's most used data types (numbers, varchar(2), dates, etc.) are very small and would lend themselves ideally to aggregating them in a small file.
So you haven't really convinced me that using ReiserFS on an Oracle Linux system does not speed up performance.

Can anyone illustrate why the ReiserFS/Oracle combination would not speed up things ? I'm not quite clear on why it would not.

Regards,

Volkmar Received on Sun Dec 02 2001 - 05:47:45 CST