Re: Storage Clause in Create Table Statement.

"Troy Simpson" <Troy_Simpson_at_ncsu.edu> wrote in message news:39AD0DE1.4AA9734F_at_ncsu.edu...
> I'm trying to understand how to allocate space to a table segment in the
> Storage Clause of the Create Table Statement. I have read what appears
> to be conflicting information. If I know before creating the table that
> I have 8 Megs of data to add to the table, should I set the Initial
> Extent to equal 8 Megs? Or, should I set all extent to be the same
> size? I have also read that the number blocks per extent may effect
> performance due to the operating system's I/O buffer size and the
> parameter db_file_multiblock_read_count in the init.ora file.
>

There's no conflict. All extents within a given tablespace should be of the same size. If different tables need different extent sizes, stick 'em in different tablespaces.

The point is: don't bother specifying a storage clause at table level. Get your storage plans right at tablespace level, and let the default storage clause there do the work on behalf of the tables.

Whatever you do, try not to allow more than half a dozen extents for a table, as more than this introduces chaining in the data dictionary, which is not a good idea.

Regards
HJR
> Here is a sample of a create table statment that I'm working with.
>
> Create Table Employee
> (
> id Number(11) NOT NULL,
> fname VarChar(30),
> lname VarChar(30),
> CONSTRAINT Employee_id_pk PRIMARY KEY ( id ) USING INDEX TABLESPACE
> Data_Indexes
> )
> Storage
> (
> Initial 10240
> Next 10240
> MinExtents 1
> MaxExtents unlimited
> PctIncrease 50
> )
> Tablespace Data_Tables
>
> Any other comments would also be appreciated.
>
> Thanks,
> Troy
>
> --
> Troy Simpson | North Carolina State University
> NCSU Libraries | Campus Box 7111 | Raleigh | North Carolina
> ph.919.515.3855 | fax.919.513.3330
>
>
Received on Sun Sep 03 2000 - 03:50:59 CDT