Re: RMAN impact
- From: "Jared Still" <jkstill@xxxxxxxxx>
- To: "Mark Brinsmead" <pythianbrinsmead@xxxxxxxxx>
- Date: Thu, 2 Nov 2006 15:22:44 -0800
On 11/2/06, Mark Brinsmead <pythianbrinsmead@xxxxxxxxx> wrote:
Some people eat broken glass, too. ;-)
Yum!
Yes, some apps (like SAP) do implement their own constraints. But the
underlying Oracle database is no longer "relational". In fact, with SAP, it
is not even close... (As I recall, it is commonplace to see multiuple
"record types" in the same Oracle table -- not even 1NF.)
Well, I never claimed that SAP does anything in a relational manner. If
Oracle were a child, Larry could charge SAP with abuse.
Just look at SAP 'Pool' and 'Cluster' tables. Ugh.
In effect, SAP has simply implemented thier own RDMBS that uses Oracle is a
big, expensive disk drive. Sort of. (At least, this is how I understand
it.)
Pretty much.
And, yes, if there are no indexes at the Oracle level in your SAP database,
you are pretty much screwed when the "logical corruption fairy" comes to
visit. ;-) (It's too long since I last looked at an SAP database -- don't
recall how the data is indexed, but I would not be at all surprised to learn
that the application "handles" that as well...)
SAP does use indexes, it would be pretty difficult to avoid that.
Just today I discovered that in some cases SAP's BW doesn't have the good
sense to
drop BITMAP indexes before loading a table. More abuse.
SAP now claims that they are on the verge of eliminating the use of a
database, but that is another story.
--
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist
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