Re: BAST in RAC
- From: Tim Gorman <tim@xxxxxxxxx>
- To: "'Oracle-L (E-mail)" <oracle-l@xxxxxxxxxxxxx>
- Date: Sat, 25 Dec 2004 10:04:23 -0700
Mladen,
With all due respect...
Having also programmed systems in both VMS and UNIX, I don't see the
functional difference between ASTs in VMS and signals in UNIX. Obviously
the APIs are quite different, but from a systems programming perspective:
* both are software based, neither is hardware based
* both execute handler code recursively in most cases, or...
* both interrupt certain types of calls unconditionally
...and, most relevant to this discussion, both are utilized by programmers
in the same fashion, for the same purpose, to implement the same
functionality, on each of their respective operating systems.
>> I see that RDB gang has exercised some terminological influence
>> over the rest of Oracle Corp.
As a significant portion of Oracle's OPS/RAC products and personnel were
purchased directly from DEC/Compaq in two waves (i.e. Rdb purchase from DEC
in 1996 and TruCluster license from Compaq in 2001), it is hardly surprising
that terms that had previously crossed over from VMS to Tru64 have now
crossed over into Oracle. I'm sure that some similar influence has
doubtlessly crossed the other way (i.e. terms like "profit", "market share",
and "winning strategy" come to mind :-) )...
>> Your description of AST is what is scientifically known as mumbo-jumbo
>> (Oracle* Mumbo-Jumbo 10g) and makes no sense whatsoever.
Or, perhaps the two functionalities are so similar as to be functionally
interchangeable, especially at higher layers in the code. Since only a few
layers of Oracle are port-specific, nitpicking on platform-specific
definitions arguably makes even less sense whatsoever.
>> Somebody probably wanted to look smart, so they used those words without
>> explanation or definition.
Probably not.
More likely, a system like OPS/RAC, abstracted from all operating systems,
is not bound by platform-specific definitions. The terms used are those
which are most useful and (yes) most familiar. They're humans, not
gods/goddesses.
I agree that it would be useful if the quality of Oracle documentation was
better, but rather than getting hung up on that, one can always refer to
online VMS documentation at places like
"http://h71000.www7.hp.com/DOC/731FINAL/5841/5841pro_023.html#overview_ast";
or to online UNIX documentation at places like
"http://www.cs.ucsb.edu/~almeroth/classes/W99.276/assignment1/signals.html";.
Peace.
-Tim
on 12/23/04 12:47 PM, K Gopalakrishnan at kaygopal@xxxxxxxxx wrote:
> Mladen:
>
> Interrupt is a generic word and it can be used anywhere in a relative
> context. CPU hardware devices may have something called interrupt and
> I am least bothered about that while speaking in RAC related context.
> In simple terms SAST/BAST are system traps sent to the owning
> processes and it is like an interrupt to that process. If you think
> that INTERRUPT should only be used to CPU/hardware decice context, you
> may want to go ahead and use that only for that purposes..
>
>> Your description of AST is what is scientifically known as mumbo-jumbo
>> (Oracle* Mumbo-Jumbo 10g) and makes no sense whatsoever. RAC processes work
>> over TCP sockets and do not "deliver interrupts". Processors and
>> hardware devices
>> deliver interrupts. Sockets deliver packets. If you want to provide
>> internal information,
>> please do it properly and not in a sloppy and misleading way using
>> incorrect and undefined terminology. This is the same comment that I've
>> sent in private email to Steve Adams when
>> he was talking about "ASTs" in his internals book.
>
> What ever information I have provided is 100% correct in RAC related
> context. If some one else is relating that with VMS or punched cards
> then I can not help :)
>
>
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