By using this site, you agree to our updated Privacy Policy and our Terms of Use. Manage your Cookies Settings.
454,237 Members | 1,256 Online
Bytes IT Community
+ Ask a Question
Need help? Post your question and get tips & solutions from a community of 454,237 IT Pros & Developers. It's quick & easy.

Configuring Extent Size

P: n/a
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
Regards,

Oct 17 '06 #1
Share this Question
Share on Google+
9 Replies


P: n/a
Racerx wrote:
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
What's an "optimized size"?

--
Knut Stolze
DB2 Information Integration Development
IBM Germany
Oct 17 '06 #2

P: n/a
I can appreciate what you're trying to do, but you're (perhaps
innocently) asking a rather large question.

I think the first thing to do is to figure out the expected
cardinalities within each table you intend your database to "host."
>From there, you can decide extent sizes (keeping in mind the goal of
minimizing dynamic extent allocations and extent interleaving),
tablespace sizing, table-to-tablespace allocation, and
tablespace-to-bufferpool allocation.

If my answer sounds like a bit of a cop-out, I apologize, and I don't
mean to sound brusque, but this topic is so well-covered in the DB2
manuals, 3rd party books, other web pages, etc. that you should have no
problem finding what you need without the need for a short-shrift
rehash here.

Regards,

--Jeff

Racerx wrote:
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
Regards,
Oct 17 '06 #3

P: n/a
For Extent:

Please go through the link given below:
http://www.db2mag.com/story/showArti...cleID=17602321

Tablespace:
Please let me know what actually you would like know for tablespace

Bufferpools:
for DSS start with 50% of the memory
for OLTP start with 75% of the available memory

Regards
Prakash Gautam
Racerx wrote:
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
Regards,
Oct 18 '06 #4

P: n/a
What I'm more inclined to ask is, "why is this so difficult?"

Why doesn't IBM put the answers to these types of questions in the
documentation?

You shouldn't have to spend 7 figures on a BCU to get this answered
definitively

jefftyzzer wrote:
I can appreciate what you're trying to do, but you're (perhaps
innocently) asking a rather large question.

I think the first thing to do is to figure out the expected
cardinalities within each table you intend your database to "host."
From there, you can decide extent sizes (keeping in mind the goal of
minimizing dynamic extent allocations and extent interleaving),
tablespace sizing, table-to-tablespace allocation, and
tablespace-to-bufferpool allocation.

If my answer sounds like a bit of a cop-out, I apologize, and I don't
mean to sound brusque, but this topic is so well-covered in the DB2
manuals, 3rd party books, other web pages, etc. that you should have no
problem finding what you need without the need for a short-shrift
rehash here.

Regards,

--Jeff

Racerx wrote:
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
Regards,
Oct 18 '06 #5

P: n/a
What I'm more inclined to ask is, "why is this so difficult?"

Why doesn't IBM put the answers to these types of questions in the
documentation?

You shouldn't have to spend 7 figures on a BCU to get this answered
definitively

jefftyzzer wrote:
I can appreciate what you're trying to do, but you're (perhaps
innocently) asking a rather large question.

I think the first thing to do is to figure out the expected
cardinalities within each table you intend your database to "host."
From there, you can decide extent sizes (keeping in mind the goal of
minimizing dynamic extent allocations and extent interleaving),
tablespace sizing, table-to-tablespace allocation, and
tablespace-to-bufferpool allocation.

If my answer sounds like a bit of a cop-out, I apologize, and I don't
mean to sound brusque, but this topic is so well-covered in the DB2
manuals, 3rd party books, other web pages, etc. that you should have no
problem finding what you need without the need for a short-shrift
rehash here.

Regards,

--Jeff

Racerx wrote:
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
Regards,
Oct 18 '06 #6

P: n/a
What I'm more inclined to ask is, "why is this so difficult?"

Why doesn't IBM put the answers to these types of questions in the
documentation?

You shouldn't have to spend 7 figures on a BCU to get this answered
definitively

jefftyzzer wrote:
I can appreciate what you're trying to do, but you're (perhaps
innocently) asking a rather large question.

I think the first thing to do is to figure out the expected
cardinalities within each table you intend your database to "host."
From there, you can decide extent sizes (keeping in mind the goal of
minimizing dynamic extent allocations and extent interleaving),
tablespace sizing, table-to-tablespace allocation, and
tablespace-to-bufferpool allocation.

If my answer sounds like a bit of a cop-out, I apologize, and I don't
mean to sound brusque, but this topic is so well-covered in the DB2
manuals, 3rd party books, other web pages, etc. that you should have no
problem finding what you need without the need for a short-shrift
rehash here.

Regards,

--Jeff

Racerx wrote:
Hi All:
Can anyone suggest me how to determine the optimised size for the
following:

1.Extends
2.Tablespaces
3.Bufferpools
Regards,
Oct 18 '06 #7

P: n/a
ts******@gmail.com writes:
What I'm more inclined to ask is, "why is this so difficult?"

Why doesn't IBM put the answers to these types of questions in the
documentation?

You shouldn't have to spend 7 figures on a BCU to get this
answered definitively
BCU tries to answer these questions definitively, for the particular
case of a data warehousing configuration. We think (and have run
enough tests before making those bcu recommendations to know) that it
will perform well with the recommendations.

DB2 overall is a pretty flexible architecture, and folks often want to
know the details of why things behave a particular way. That's what
the docs being pointed to explain.

So you can just go with the configurations defined in the BCU, and if
you want to understand why it is explained in the various docs.

Regards,
- Haider
Oct 18 '06 #8

P: n/a
Haider Rizvi <ha*****@gmail.comwrites:
BCU tries to answer these questions definitively, for the
particular case of a data warehousing configuration. We think (and
have run enough tests before making those bcu recommendations to
know) that it will perform well with the recommendations.
Pressed send too fast ...

I'd gladly take feedback on the BCU docs, and things you find to be
unclear / incomplete. Feel free to email me with feedback.

Regards,
--
Haider

PS: This is not an invitation to email me asking for tuning advice,
bypass support or things that should be discussed here in the
newsgroup.
Oct 18 '06 #9

P: n/a
The BCU documentation is *excellent*-- What I am suggesting is the
generic documentation provided similar recommendations . Obviously the
recommendations would not be as granular as the BCU, but guidelines
based on specific manufacturers -- or tools to benchmark performance to
derive these types of settings would be great.

As a big DB2 fan running on non IBM hardware, I am left to my own
devices to arrive at the correct tunables. Since we see questions like
the OPs almost daily, I just posed the what is at a minimum my desire
for what I'd like to see from IBM.

Given the maturity of the project, noobs (and non-noobs!) shoulds have
access to better direction/documentation. (IMHO)
Cheers

Haider Rizvi wrote:
Haider Rizvi <ha*****@gmail.comwrites:
BCU tries to answer these questions definitively, for the
particular case of a data warehousing configuration. We think (and
have run enough tests before making those bcu recommendations to
know) that it will perform well with the recommendations.

Pressed send too fast ...

I'd gladly take feedback on the BCU docs, and things you find to be
unclear / incomplete. Feel free to email me with feedback.

Regards,
--
Haider

PS: This is not an invitation to email me asking for tuning advice,
bypass support or things that should be discussed here in the
newsgroup.
Oct 18 '06 #10

This discussion thread is closed

Replies have been disabled for this discussion.