Re: db_block_size = 16K inflates tables

Hi Ivan,

I think your "problem" is not associated block size but with the fact you are using ASSM. It doesn't insert data in the traditional 'from left to right' method but will 'select' an appropriate block from the bitmap matrix and insert the row. As such, these gaps are an issue if you wish to insert an initial small number of rows.

Try without ASSM and see how many blocks Oracle uses. You will be pleased with the results.

Cheers

Richard
"ivan vasquez" <ivan_at_itos.uga.edu> wrote in message news:aqs1sg$4q3$1_at_cronkite.cc.uga.edu...
> Hi,
>
> I just installed a 9.2.0 instance for GIS applications (ESRI ArcSDE). The
> manufacturer suggests using db_block_size = 16K. After a first
installation
> using block size 8K, I reinstalled the database using 16K to see if the
> performance improved. However, a more important problem appeared: Tables
are
> growing way too fast.
>
> (All tablespaces have been created locally managed, auto segment space
> mgmt.)
> In a 8K blocksize tablespace, a table with only 160 rows, 46 bytes per
row,
> uses 5 data blocks.
> In a 16K blocksize tablespace, the exact same table uses 61 data blocks!
>
> The tables were created with no storage statements, so defaults should
> apply. The data was retrieved from user_tables after analyzing them.
>
> What could be "wrong"?
> Thank you,
> Ivan.
>
> Table description:
>
> SQL> desc ga_cnt00
> Name Null? Type
>
> ----------------------------------------- -------- -----------------------
-
>
> OBJECTID NOT NULL NUMBER(10)
>
> AREA NUMBER(24,5)
>
> COUNTY VARCHAR2(5)
>
> NAME VARCHAR2(13)
>
> LR_ID NUMBER(16)
>
> POP00 NUMBER(16)
>
> ID VARCHAR2(5)
>
> SHAPE NUMBER(10)
>
>
>
>
Received on Tue Nov 12 2002 - 18:55:14 CST