Re: Synchronous writes & TEMP

From: Frank van Bortel <fvanbortel_at_netscape.net>
Date: Sat, 15 May 2004 19:48:26 +0200
Message-ID: <c85kus$qqs$1@news5.tilbu1.nb.home.nl>

VC wrote:
[]

> One would imagine that the terminlogy's been sort of obvious for anybody
> familiar with OS basics at the undergraduate level but I guess I was too
> optimistic.

I thought I made it perfectly clear, that I am not into these "under the hood" things. If you fail to see that in the phrase "ready to be beaten, technically speaking ;) ", so be it.

And no - I left school before operating systems were taught; hell, QDOS even had to be developed, as CP/M, OS9, etc.

>
> [FB]
>

>>So my best guess is: it in the habit of Oracle to use
>>synchronous writes.

>
>
> I do not understand what 'habit' means in this context -- we are not talking
> about some creatures are we ?

Actually - I was. Programmers at Oracle. Open a file; use synchronous writes. What you are saying is: Yeah, but this is the temporary tablespace file, let's think this over.
All I'm suggesting is: nobody thought it over - yet. Temporary files for temp TS isn't that old; 8.0? In the sql.bsq there are still comments about IOR... []

>

>>Does it make any difference at all? You state it does, but
>>we had this raw IO vs buffered IO thread not too long ago.
>>I'd like to see some test results, presumably from a C-program
>>(as Oracle will always use O_DSYNC)

>
>
> Again, you are disputing something relly basic. Please read about why
> operating systems implement buffered I/O at all and you would not need to
> perform any such tests ("Advanced Unix Programming", by R. Stevens)..
>

Well - looking at the responses on this thread, it's not *that* basic.

> The thread you are referring to is irrelevant since TEMP datafiles are
> different form others because:
> a. one does not care about potential data loss (presumably, unless someone
> can explain to me where I am wrong);

No, you don't care, I agree, but having data loss would be: 1) a liability (due to possibly incorrect results from data processing) 2) a performance killer (having to write again)

> b. I/O to those files is not cached by Oracle;

Well - I could not find that anywhere. Fact is, nowhere in the Concepts manual (V9) temporary datafiles are mentioned as being different from ordinary datafiles.
>
> I do apologize for my harsh words but I was getting really frustrated with
> people's inablity to understand what I was trying to ask despite my failed
> attempts to clarify the meaning several times ...
>

No need - I did not/do not feel offended, and appreciate your contributions.
>
> P.S.:
>
> [quote="Meriam-Webster"]
>
> Main Entry: Em·bar·ras
> Variant(s): or Em·bar·rass /'am-"bro--sic/
> [/quote]
>

My spelling checker (Netscape Gecko US English) insisted on 2 s's. I remembered it as the correct spelling, too. L'embarras is French, as well as a river.

> [quote="The Free On-line Dictionary of Computing, © 1993-2003 Denis Howe"]
>
> orthogonal
>
> adj. [from mathematics] Mutually independent; well
> separated; sometimes, irrelevant to. Used in a generalization of
> its mathematical meaning to describe sets of primitives or
> capabilities that, like a vector basis in geometry, span the entire
> `capability space' of the system and are in some sense
> non-overlapping or mutually independent.
>
> [/quote]
>
>
> Regards.
>
> VC
>
>

-- 

Regards,
Frank van Bortel

Received on Sat May 15 2004 - 12:48:26 CDT