Re: O_DIRECT question

[Bill Davidsen <davidsen@tmr.com>]

Denis Vlasenko wrote:

> Well, I too currently work with Oracle.
> Apparently people who wrote damn thing have very, eh, Oracle-centric
> world-view. "We want direct writes to the disk. Period." Why? Does it
> makes sense? Are there better ways? - nothing. They think they know better.
> 
I fear you are taking the Windows approach, that the computer is there 
to serve the o/s and applications have to do things the way the o/s 
wants. As opposed to the UNIX way, where you can either be clever or 
stupid, the o/s is there to allow you to use the hardware, not be your 
mother.

Currently applications have the option of letting the o/s make decisions 
  via open/read/write, or let the o/s make decisions and tell the 
application via aio, or using O_DIRECT and having full control over the 
process. And that's exactly as it should be. It's not up to the o/s to 
be mother.

> (And let's not even start on why oracle ignores SIGTERM. Apparently Unix
> rules aren't for them. They're too big to play by rules.)

Any process can ignore SIGTERM, or do a significant amount of cleanup 
before exit()ing. Complex operations need to be completed or unwound. 
Why select Oracle? Other applications may also do that, with more or 
less valid reasons.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot