Datablocksize and Freespace


Datablocksize and Freespace

Hi everybody!

What is the purpose of mentioning of Datablocksize and Freespace in the create statement?
Can anybody elaborate on this?

Thanks in advance


Re: Datablocksize and Freespace

A Datablock is a unit of space allocated to Table(not shared between tables)
Datablocksize gives the maximum permitted size of the block that will be allocated for the table.

Freespace percent is the percentage of cylinder space to leave free during load operations.
(To accomodate future insertions or row updations in the same cylinder)

There are lots of things to keep in mind w.r.t Datablocksize. some of them are...
- If the size is large then we can have multiple rows in the same block and it would be efficient
when it comes to retrieval as multiple records can be obtained from a single I/O.
- If size is less then its possible to hold these blocks in memory and process them faster

Please refer the technical documentation available at the Teradata site for more/specific details about
these topics.

Annal T