Re: 9.2.0.4: Build single task EXP

From: Michael Schmarck <michael.schmarck_at_here.la>
Date: Sat, 30 Aug 2008 08:27:27 +0200
Message-ID: <6hs7g7Fnimt5U1@mid.individual.net>


· joel garry <joel-garry_at_home.com>:

> On Aug 29, 10:12 am, Michael Schmarck <michael.schma..._at_here.la>
> wrote:

>> · sybra..._at_hccnet.nl <sybra..._at_hccnet.nl>:
>>
>> > On Fri, 29 Aug 2008 15:01:59 +0200, Michael Schmarck
>> > <usenet-mich..._at_schmarck.cn> wrote:
>>
>> >>Is it at all possible to build expst on 9.2.0.4?
>>
>> > The question is irrelevant.
>>
>> No, it's not. Other people seem to be able to build expst
>> in Oracle 9.2.0. I'm not. So I wonder if I'm doing something wrong.
>> Or rather: I wonder what am I doing wrong.

>
> You are missing a file, and you don't know how to figure out how or
> why that file is not there. You are assuming (perhaps correctly) that
> an hp explanation is the same as your sparc problem.

I based that assumption on the fact, that somebody quoted Metalink. Granted, I don't know if he quoted from some HP-ony section of some Metalink document.

> You are
> incorrectly assuming 9204 is as good or better than 9208.

I don't assume that. I have 9204 installed. expst doesn't seem to build on my 9204 installation. I'm asking if it should be possible to build expst on 9204. It would also be a very good information for me, if someone could confirm that expst can be build on 9208.

> You are
> assuming that the reason exp is slow is because of interprocess
> communication.

I'm just looking for a way to speed up EXP.

>> > First of all, only 9.2.0.8 is potentially supported, all other
>> > versions are in sustained support.
>>
>> Understood. Is that important for the question that I asked?

>
> Yes.

Why?

>

>>
>> > Oracle has stated specifically it doesn't support single task linking,
>> > so whatever 'tric' you are going to apply, they are not going to
>> > support it.
>>
>> Understood. But I didn't ask Oracle, did I? :) At least I did not ask
>> them on an "official channel", so to speak.
>>
>> Any, that doesn't answer the question, does it? :) Would it be possible
>> to build expst on 9.2.0.8? Should it possible to build it on 9.2.0.4?

>
> Perhaps you might read into it that if Oracle doesn't support it, it's
> not worth even trying.

There are so many "unsupported" things out there in the IT world, that "it's unsupported by vendor" doesn't really mean much. Especially, if you don't get support from the vendor.

>> > Apart from that:
>> > There are conventional methods to speed up export.
>> > To mention a few
>> > - Make sure you don't use TCP/IP as a communication mechanism, but use
>> > BEQ and/or IPC instead
>>
>> I'm running EXP on the database server. I suppose EXP of 9.2.0 is clever
>> enough to use the fastest communication mechanism.

>
> No, it does what you tell it to.

Of course :)

>> > - use Direct=Y
>>
>> I'm doing that.

>
> That's likely to give the most effect, much more than the relinking,
> for modern OS implementations.

All right. But it would still be interesting to see if expst would be a speed improvement.

>> > - if you don't use direct, crank up the buffer parameter on the exp
>> > commandline
>>
>> I use BUFFER=20m and recordlength=64k.

>
> Be sure you understand when this is used, when DIRECT is not used.

Well, but it doesn't hurt to specify a buffer, does it? After all, the doc says that buffer is ignored, when direct=y is used.

>> > If you desire to speed up exp because you use it as a backup, you need
>> > to be warned: export does not constitute a backup.
>>
>> It allows to recover data, which is stored in the export. That's
>> sufficient.

>
> It might allow restoration, recovery is a special term in the Oracle
> world, which logical backups do not do.

Fine. But it's true that it allows to "re-get" what's in the EXP dump, isn't it? :)

> Note the "might," exp is a rickety old thing whose main purpose is not
> backing up. It can be helpful for certain situations. I take one
> nightly if possible, it's helped me out many times.

That's what I do as well - I take an EXP dump and then I make a backup.

> You do not want to base a backup strategy on it.

Of course not. And I don't.

> Oracle is very clear
> about that in the backup docs.

Yes, they are.

> My own experience has been, when management clearly states they only
> need to recover to the previous night, they are lying, often to
> themselves.

In that specific case, they don't, because the application is written in a specific way, that makes it completely useless to be able to do a point-in-time recovery of only the Oracle stuff.

> Get an SLA.

What makes you think, that I don't have one? Just because I want to make the "convenience exp" run faster?

Michael Received on Sat Aug 30 2008 - 01:27:27 CDT

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