Question - changing the NEXT extend size manually

[Former Member]

Hi Guys,

I would like to get clarification on the subjected topic. During DB reorg, we have an option to change the next extend size manulay. If I want to change the next extend size , which is the best practise to follow on deciding the next extend size? Is there any method to calculate the best next extend size?

Also, I would like to know , after a DB reorg - how continuous freespace in a tablespace changes...(i.e) DB02 --> Freespace statistics --> Tablespace --> freespace analysis

Does the continuous freespace has any direct relation with the next extend size that we choos during the DB reorg?

Please also share the link if there is any literature on this topic.

Best regards,

Vinodh.

[fidel_vales]

Hello,

From the question I can assume that you are using dictionary managed tablespaces.

Before I ask your question I'd like to suggest you to use Locally Managed Dictionary tablespaces, you will not have to "worry" about next extent size.

Not sure how did you performed the reorganization. I assume (again) you used SAPDBA.

It is a long time I do not use SAPDBA. I'm not sure if the NEXT extent you specify there is for the tablespace or each of the tables.

If the one specified is for the tablespace, then, in a SAP system, it is not used. SAP spcify the value of NEXT extent for each object it is created.

If you would have the same "next extent value" in all objects in a tablespace, then the objects will allocate extents of same size. If an object is dropped then the free space left will be proportional to te next extent size.

If the objects in the tablespace have different values for the next extent, then the contiguous blocks of free space can have different sizes.

This is one of the reasons of using LMTS, do not worry about next extent size.

[Former Member]

Hello Fidel,

Yeap...I use DMTS and I am using SAPDBA for reorg.... I am changing the next extend size for each objects and indexes in a tablespace.

regards,

VInodh

[fidel_vales]

Hi,

Then what I said before applies.

If ALL your objects have the next extent size then you can think that the contiguous free space on the tablespace will be a multiple of this size ( perhaps when there is no more free space )

There is no method to calculate the "best extent size", as I mentioned before, the best is not to use Dictionary managed tablespaces but LMTS and you will not have to think about that.