Default Value for NEXT

When you carry out a reorganization or an export, SAPDBA recommends extent sizes for the object you are reorganizing or exporting. You can influence the calculation of the default value for extent parameter NEXT with the option Use ABAP/4 Dic. for NEXT. The basis for calculating the NEXT parameters are tables DD09L and TGORA/IGORA.

SAPDBA calculates a default value for the NEXT extent size as follows:

• Use ABAP/4 Dic. for NEXT: yes

The new value for NEXT is calculated as the maximum of the following two values:

1. An SAP object is assigned a size category via table DD09L. The NEXT value is determined from table TGORA/IGORA based on that category. (This point does not apply if there is no category assigned in DD09L.)
2. SAPDBA determines the maximum from the following values:

• Current NEXT value
• 10% of the total allocated space

SAPDBA compares this value (the maximum of 1. and 2.) with the values for the extent size in TGORA/IGORA. SAPDBA chooses the next smaller value found in TGORA/IGORA as the new NEXT value (the NEXT value therefore can become somewhat smaller than the current value under certain circumstances). NEXT values which are larger than the largest TGORA/IGORA value are not reduced. If TGORA/IGORA does not exist, SAPDBA uses internal default values which correspond to the values in TGORA/IGORA (see "Values in TGORA/IGORA").

• Use ABAP/4 Dic. for NEXT: no

No comparison with DD09L and TGORA/IGORA is performed; instead the greater of the two following values is used:

• 10% of the total allocated space.
• The current value for NEXT

Values in TGORA/IGORA

Defining the NEXT values to correspond to the permanently assigned values in the TGORA/IGORA tables results in less wastage in the tablespace. If the extent values are defined using a size category assigned in the ABAP/4 Dictionary (see Technical Configuration), incorrectly defined values can be corrected in the database without great difficulty.

NEXT values in TGORA/IGORA

Size category	NEXT value for table (in KB)	NEXT value for indexes (in KB)
0	16	16
1	160	80
2	640	160
3	2560	640
4	10240	2560
5	20480	5120
6	40960	10240
7	81920	20480
8	163840	40960
9	327680	81920
10	655360	163840
11	1310720	327680
12	2621440	655360
13	5242880	1310720
14	10485760	2621440

You can change this distribution manually, but you should note the following when doing so:

• Tables of size category 14 can reach a size of about 1000 GB and indexes a size of 250 GB for 100 assigned extents with the current default values. You should therefore reconsider whether larger values are really required.
• The extent values (except for category 0) are rounded to a multiple of 5*
db_block_size (above table: to a multiple of 40KB) in order to avoid additional ORACLE rounding. If you change values or insert new ones, it is best if you also specify only the corresponding multiple.