| Parameter | Specify . . . | Minimum | Maximum | Default |
|---|---|---|---|---|
| NSISN | the maximum number of ISNs per element in the table of ISNs (TBI). | 7 | see text | 51 |
The parameter NSISN specifies the maximum number of ISNs kept in a TBI element in memory (list of resulting ISN lists). The more ISNs that are kept in memory, the fewer the Work I/Os needed to read additional resulting ISN lists from the Work dataset. This parameter influences the performance of the L1/4 command with the "N" (GET NEXT) option.
The highest value that can be specified for NSISN depends on the Work device. For Adabas-specified Work block sizes, the maximum values are shown in the following tables:
The following tables do not apply to user-defined Work block sizes; in this case, the maximum is determined as follows, where WORK is the block size of the Work dataset:
(WORK - 6) / 4
The TBI element has a length of 64 + (NSISN * 4) bytes in the TBI pool (see the LI parameter).
Although supported, the BS2000 device type 2007 is not recommended for use with Adabas. Support for the 2007 will be removed in a later Adabas release.
| Device Type | Max. Value | Device Type | Max. Value |
|---|---|---|---|
| 3310 | 1022 | 8345 | 5728 |
| 3330 | 1061 | 8350 | 2358 |
| 3340 | 877 | 8380 | 2267 |
| 3350 | 1155 | 8381 | 2867 |
| 3359 | 1155 | 8385 | 5865 |
| 3370 | 1278 | 8390 | 2674 |
| 3375 | 1022 | 8391 | 3418 |
| 3379 | 1022 | 8392 | 4611 |
| 3380 | 1371 | 8393 | 6995 |
| 3389 | 1371 | 9332 | 1278 |
| 3390 | 1429 | 9335 | 1278 |
| 9345 | 2785 |
| Device Type | Max. Value | Device Type | Max. Value |
|---|---|---|---|
| 2000 | 1022 | 2010 | 4096 |
| 2001 | 1022 | 2200 | 4096 |
| 2002 | 2046 | 2201 | 3072 |
| 2003 | 1534 | 2202 | 4096 |
| 2004 | 2558 | ||
| 2005 | 2046 | ||
| 2006 | 2558 | ||
| 2007 | 7678 | ||
| 2008 | 8188 | ||
| 2009 | 8188 |
The maximum number of ISNs per TBI element during the Adabas session is 400.
ADARUN PROG=ADANUC,NSISN=400
You can override this parameter setting for an individual user by specifying a different value in the Adabas control block for an OP command. See the discussion of the OP command in the Adabas Command Reference documentation.
