A fix is available
APAR status
Closed as new function.
Error description
This is the fourth APAR (following PH21370, PH24358, and PH26317) for E491, Db2 12 zPARM simplification
Local fix
N/A
Problem summary
**************************************************************** * USERS AFFECTED: * * All Db2 12 for z/OS users and Db2 11 for * * z/OS users who are migrating to Db2 12. * **************************************************************** * PROBLEM DESCRIPTION: * * This APAR removes the following * * obsolete subsystem parameters from * * Db2 12: * * - DSN6SPRM.CACHEPAC * * - DSN6SPRM.CACHERAC * * - DSN6SPRM.IRLMAUT * * - DSN6SPRM.IRLMSWT * * - DSN6SPRM.CHGDC * * - DSN6SPRM.EDPROP * * - DSN6SYSP.PCLOSEN * * - DSN6SYSP.MGEXTSZ * **************************************************************** * RECOMMENDATION: * **************************************************************** The following subsystem parameters are obsolete or rarely used: CACHEPAC determines the amount of storage in bytes to allocate for caching package authorization information for all packages on a Db2 member. Currently, the default setting is 5242880. CACHERAC determines the amount of storage in bytes to allocate for caching routine authorization information for all routines on a Db2 member. Currently, the default setting is 5242880. IRLMAUT specifies whether Db2 is to automatically start and stop the IRLM. Currently, the default setting is YES. IRLMSWT specifies the amount of time in seconds that Db2 is to wait for the IRLM to start during autostart. Currently, the default setting is 120. CHGDC specifies whether CHANGE DATA CAPTURE support is enabled. Currently, the default setting is NO. EDPROP specifies whether changes to table defined for DATA CAPTURE CHANGES will be allowed unless they are propagated. Currently, the default setting is NO. PCLOSEN specifies the number of consecutive Db2 checkpoints that a page set or partition remains read-write after it is updated. After the specified number of checkpoints occur, Db2 converts the page set or partition to read-only. Currently, the default setting is 10. MGEXTSZ specifies whether secondary extent allocations for Db2-managed data sets are to be sized according to a sliding scale. Currently, the default setting is YES. -------------------------------------------------------------
Problem conclusion
Temporary fix
Comments
To simplify configuration and management of Db2 and encourage best practices, the following subsystem parameters are removed from Db2 12: CACHEPAC, CACHERAC, IRLMAUT, IRLMSWT, CHGDC, EDPROP, PCLOSEN, and MGEXTSZ. When the fixing PTF is activated, Db2 will always do the following actions: - set the amount of storage to allocate for caching package authorization information for all packages and for caching routine authorization information for all routines on a Db2 member to 10485760 bytes. However, if COMCRIT=YES, the amount of storage is set to 0 bytes. - automatically start and stop the IRLM as part of Db2 startup and shutdown. - set the amount of time that Db2 is to wait for the IRLM to start during autostart to 120 seconds. - always allow changes to tables defined with DATA CAPTURE CHANGES, but the SQL changes will not be propagated. Db2 will now behave as if, before this APAR, CHGDC and EDPROP are both set to NO (or DPROP SUPPORT field = 1 on the panel DSNTIPO). - set the number of consecutive Db2 checkpoints that a page set or partition remains read-write after it is updated to 32767. If the data set pseudo close process that is triggered by PCLOSEN is more frequent than by PCLOSET, users should update PCLOSET value accordingly as needed. - automatically optimize the secondary extent allocations for Db2-managed data sets to be sized according to a sliding scale. ------------------------------------------------------------- Pre-APPLY guidance for customers who currently set MGEXTSZ=NO: ------------------------------------------------------------- If you currently set MGEXTSZ=NO on Db2 12, be aware that any Db2 subsystem or data sharing member where this PTF is activated, Db2 automatically optimizes the secondary extent allocations for Db2-managed data sets to be sized according to a sliding scale. Activating the PTF on a Db2 subsystem or data sharing member means that you have: - applied it there; and then - rebuilt the Db2 subsystem parameter (DSNZPxxx) module; and then - either restarted Db2 or run the -SET SYSPARM LOAD or RELOAD command with the rebuilt subsystem parameter (DSNZPxxx) module If you currently set MGEXTSZ=NO on Db2 11, including members in data sharing coexistence with Db2 12, be aware that Db2 automatically optimizes the secondary extent allocations for Db2-managed data sets to be sized according to a sliding scale on any Db2 subsystem or data sharing member that you have migrated to Db2 12 where this PTF is activated. Therefore, before you either : - apply the fixing PTF for this APAR on a Db2 12 subsystem (or any member of a Db2 12 data sharing group); or - migrate a Db2 11 subsystem (or any member of a Db2 11 data sharing group) to Db2 12 with this PTF applied you need to rebuild its Db2 subsystem parameter (DSNZPxxx) module to use MGEXTSZ=YES (on all members in data sharing). Do not run the -SET SYSPARM or restart Db2 command on any member until you have switched all members to use MGEXTSZ=YES. After switching (all members) to MGEXTSZ=YES, run (on all members in data sharing) the -SET SYSPARM command or restart Db2 (all members in data sharing) to initiate the change.
APAR Information
APAR number
PH28280
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
C10
Status
CLOSED UR1
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-08-06
Closed date
2020-10-01
Last modified date
2020-11-02
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI71872
Modules/Macros
DSNTINMF DSNDQWPZ DSNTIP7 DSNWZIFC DSNTIDXA DSNTIVMD DSNTIJUZ DSNTINST DSNTIDXC DSNTIWIA DSNTIDXB DSNTIVIA DSNTIWMD DSNTIWIE DSNTIVIE DSN6SYSP DSN@XAZP DSN6SPRM DSNTXAZP DSNTIWPC DSNTIPP DSNDSPRM DSN6SPRC DSNTIPO DSNTIPL1 DSNTIPI DSNTIVMN DSNTIWMN DSNTIVAF DSNTIVIN DSNTIWMS DSNTIVMS DSNTIWAF DSNTIWIN
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
RC10 PSY UI71872
UP20/10/09 P F010
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
31 March 2021