Re: estimation of table size in oracle 9i

dkornyushin_at_gmail.com wrote:
> Please advice how to estimate in advance phisycal size of table in 9i
> or give a reference on dbf (oracle data file) format. I tried to test
> some scenarios but I got quite confused cause even for number fields
> size of table in bytes (measured by dba_extents) depends on values in
> fields
> For example if I create table
>
> create table t_num (t number,t1 number,t2 number,t3 number)
>
> and insert 1048576 of records
>
> insert into t_num values (1078,2000,3001,238)
>
> table size is 24 117 248
>
> if I'm inserting same number of records (definitely I dropping table &
> create it again before experiment)
>
> insert into t_num values (1077,2001,3002,237)
>
> table size is 25 427 968
>
> how this can be explained?

The calculation is in the docs at http://tahiti.oracle.com: Look it up.

Possibly in 9i but definitely in 10g and above use the DBMS_SPACE built-in package's CREATE_TABLE_COST procedure.

-- 
Daniel A. Morgan
University of Washington
damorgan_at_x.washington.edu (replace x with u to respond)
Puget Sound Oracle Users Group
www.psoug.org