Adjust subsystem parameter settings for parameters removed in Db2 13

Before you can migrate to Db2 13, you must set the values of certain subsystem parameters that are removed in Db2 13.

Procedure

To adjust for subsystem parameters that are removed in Db2 13, complete the following steps:

Modify your subsystem parameter module to specify the following settings.
Subsystem parameter Setting used in Db2 13 Description in earlier releases Incompatible change?
AUTHCACH 4K Specifies the size (in bytes per plan) of the authorization cache that is to be used if no CACHESIZE is specified on the BIND PLAN subcommand. No
DDF_COMPATIBILITY NULL

Controls certain characteristics of a connection between a client application and a Db2 for z/OS data server.

 Yes
DSVCI YES Controls whether Db2-managed data sets that are created by CREATE TABLESPACE or CREATE INDEX statements are to have variable VSAM control intervals. No
EXTRAREQ 100 Limits the number of extra DRDA query blocks that Db2 can request from a remote DRDA server. No
EXTRSRV 100 Limits the number of extra DRDA query blocks that Db2can return to a DRDA client No
HONOR_KEEPDICTIONARY NO

Specifies whether Db2 honors the LOAD and REORG parameter KEEPDICTIONARY when tables are converted between basic row format and reordered row format.

 No
IMMEDWRI NO Determines when updates to group buffer pool-dependent buffers are to be written to the coupling facility. No
IX_TB_PART_CONV_EXCLUDE YES Specifies whether to exclude trailing columns from the table-controlled partitioning keys when table spaces are converted from index-controlled partitioning to table-controlled partitioning. No
MAXARCH 10000

Controls the maximum number of archive log volumes that are to be recorded in the BSDS.

 No
MAXTYPE1 0 Determines the number of inactive DBATs that Db2 is to allow. No
OPT1ROWBLOCKSORT DISABLE Specifies whether Db2 explicitly blocks sort operations when the OPTIMIZE FOR 1 ROW clause is specified on a query. No
PARA_EFF 50 Controls the efficiency that Db2 assumes for parallelism when Db2 chooses an access path. No
PLANMGMTSCOPE STATIC Specifies the types of SQL statements for applying the PLANMGMT subsystem parameter setting. No
REALSTORAGE_MANAGEMENT AUTO 1 Specifies whether Db2 should manage real storage consumption.
Important: Keep your current setting in Db2 12. See note 1.)
 No
RESYNC 2 Specifies the time interval, in minutes, between resynchronization periods. No
SUBQ_MIDX ENABLE Specifies whether to enable or disable multiple index access on some non-Boolean uncorrelated subquery predicates. No
TRACSTR NO Specifies whether the global trace starts automatically when Db2 starts. No
Notes:
  1. If you currently use a different setting, do not change the REALSTORAGE_MANAGEMENT setting to AUTO in Db2 12.

    Db2 13 uses enhanced automatic behavior for real storage management, which differs from the thread-based discard processing used with REALSTORAGE_MANAGEMENT=AUTO in Db2 12 or earlier.

    Db2 13 manages real storage discard processing at the system level to avoid z/OS RSM serialization from discard requests.

In data sharing, you must ensure that all members of the group run with these settings before migrating any member of the group to Db2 13.