4.3.8 Estimating memory requirements during execution of the adbunarchivechunk command

The following table shows the formula for calculating the amount of memory required when the adbunarchivechunk command is executed.

Table 4‒10: Memory requirement determinations (during execution of the adbunarchivechunk command)
No.	Memory type		Formula (megabytes)	Related server definitions
1	Shared memory	Shared memory management area	`100`	None
2		Global buffer page	`dbarea_num` `x 1,024`	`adbbuff` operand
3		Process common memory	`1,024 +` `max_users` `+` `GBUF`	`adb_sys_proc_area_max` operand `adbbuff` operand
4		Real thread private memory	`512 +` `SORTBUF` `+` `BLKBUF`	`adb_sys_rthd_area_max` operand
5	Process memory	Heap memory	`1,024 +` `sort_rthd` `x 0.5`	None

Explanation of variables

dbarea_num

Number of data DB areas

If this value cannot be estimated, use the combined total number of tables and indexes that will be defined.

max_users

Value specified for the adb_sys_max_users operand in the server definition

GBUF

Global buffer

Assume 20 megabytes for each 400 megabytes of the global buffer page size calculated in No. 2.

SORTBUF

Sort buffer

Use the following formula to determine the value.

Formula (megabytes)

[Figure]

sort_buff_size

Value specified for the unarchive chunk option adb_unarcv_sort_buff_size

sort_rthd

Use the following formula to determine the value.

value-specified-for-unarchive-chunk-option-adb_unarcv_rthd_num - 1

BLKBUF

Buffer for creating indexes

Use the following formula to determine the value.

Formula (megabytes)

[Figure]

buff_blk_size

Assume 4,096.

buff_blk_num

Value specified for the unarchive chunk option adb_unarcv_buff_blk_num

unarcv_rthd

Use the following formula to determine the value.

value-specified-for-unarchive-chunk-option-adb_unarcv_rthd_num - 1

txt_sort_buff_size

Value specified for the unarchive chunk option adb_unarcv_txt_buff_size