Initial,Next Extents and Byte allocation confusion

From: Poorna Prakash <poorna_prakash_at_sabre.com>
Date: 1998/02/06
Message-ID: <34DB898E.3EBE@sabre.com>#1/1

Please clarify the confusion I have on extent allocation and the bytes allocated. Upon inquiring the USER_INDEXES & USER_SEGMENTS data dictionary view, I stumbled upon this phenomenon, which shows two different results as far as the byte allocation is concerned, which I could
not comprehend. Any insight would be appreciated.

USER_INDEXES

Index Name Table Name Initial Ext Next Ext Min. Ext. PCT Increase
---------- ---------- ----------- -------- ---------

CUST_PK       CUSTOMER           36864      40960          
1             50
ORDER_PK      ORDER              12288      40960          
1             50

USER_SEGMENTS

Segment Name Bytes Extents
------------ -------- -------

CUST_PK           40960         1
ORDER_PK          28672         1

My question is shouldn't the BYTES column in the USER_SEGMENTS show 38684 & 12288.
Why is the bytes column displayed as 40960 & 28672, when the formula to calculate
the bytes allocated in this case (only one extent allocated) should be

(number of extents) X (initial extent)

ie.,                1   X  36864           = 36864 bytes
                    1   X  12288           = 12288 bytes

Thanks for your time and reply.

-Prakash
Received on Fri Feb 06 1998 - 00:00:00 CST