DSNTIJUZ - installing dsnzparm

DSNTIJUZ

DSNTIJUZ is the IBM supplied jcl used to update / install DSNZPARM.DSNTIJUZ usually resides in SDSNSAMP.We use Clist/rexx while installing (SDSNCLIST) .

Always recommended to use same DSNTIJUZ each time to avoid change in values or discrepancies.

Zparms resides on system libraries, so we need external tools or ibm supplied clist/rexx (DSNZWP) to view existing system parameters in system.

DB2 uses zparm as complied load modules.

Dynamic update

Print existing DSNZPARM

Ø  Confirm with customer whether its dynamic or permanent change

Ø  If it is dynamic update DSNZPARM jcl with new parameters.Update DSNZPARM name as well

Ø  Submit jcl

Ø  Issue set command to make new zparm name

-SET SYSPARM LOAD(newzparm)

Ø  Print current DSNZPARM,verify updated system parameters.

Permanent Change

Ø  Check dynamic or permanent change and its feasibility

Ø  Print current DSNZPARM

Ø  Edit DSNTIJUZ jcl for changes in parameters

Ø  Bring down DB2 subsystem

Ø  Submit DSNTIJUZ jcl

Ø  While submitting DSNTIJUZ we will get RC=0 eventough DB2 is up.SO ensure to stop DB2 before submitting DSNTIJUZ.

Ø  Bring up DB2 subsystem

Ø  Print DSNZPARM and verify changes.

Commands

-SET SYSPARM LOAD(newzparm)

            Used to update DSNZPARM

-SET SYSPARM STARTUP

            Update existing permanent DSNZPARM, which was there during startup.

Online Updateable List

You would find the complete list of parameters in the Installation and Migration manual.

DB2 SYSTEM CONFIGURATION PARAMERTERS - DSNZPARM

DSNZPARM Dissected

What isDSNZPARM

Dataonly,subsystemparameterloadmodulecontainingtheDB2execution-timeparameters

InitiallysetatinstalltimethroughtheinstallationISPFpanels

Includesmacros:

o   DSN6ARVP–Archivedatasetparameters

o   DSN6ENV– DB2environmentsettings(removed)

o   DSN6FAC– DDF

o   DSN6LOGP–Logstuff

o   DSN6SPRM– InitializationparametersforDBM1

o   DSN6SYSP–Miscellaneoussystemparameters

o   DSN6GRP–Groupstufffordatasharing

Install DSNZPARM

SomeDSNZPARMsaresetoutsidetheinstallpanels

o   Hidden

§  Justwhattheword implies,theyareburiedwithinthemacros and notintended tobemodified bythegeneralpublic .IBM intervention needed to change those.

o   Opaque

§  Arenotavailableforchangeusingthepanels

o   Visible

§  Changedusingtheinstallpanels

DSNZPARM Values

Default values (recommended) / Minimum  values / Maximum values

Updating DSNZPARM

Ø  Permanent change

o   Need to recycle DB2 .

o   Changes will be permanent and will get updated in SDSNLOAD

o   New ZPARM name is recommended for each change

Ø  Temporary Change

o   Its Dynamic change – No need to recycle DB2

o   Not all values can be updated dynamically

o   Change will get rolled back , post recycle of DB2.

Datasharing

Multiple database shares common buffers and objects.

Log Range sequence number(LRSN)  used while logging .

LRSN = RBA+Timer

DB2 system component Architecture

Ø  Catalog tables

Ø  Directory

Ø  Logs

Ø  BSDS

Catalog tables

o   We used to have more than 120+ tables in a system

o   Each tables have specific functions

o   We need system Authority (SYSADM/DBADM) to use catalog tables

System tables

Maintains high level information about tables, table owners, schema, created date, respective  Table spaces,DB,Any existing foreign key. While querying tables we use schema names, since we are using logical objects.

SYSIBM.SYSTABLES

SYSIBM.SYSTABLESPACES

SYSIBM.SYSDATABASES

SYSIBM.SYSCOPY

SYSIBM.SYSUSERALL

SYSIBM.PLANS

ETC..,

Directory blocks

We use less than 10 blocks

Non accessible using SQL

To access IBM supplied rexx required.

SKCT01                 -              pkg table

SKPT01                 -              Plan table

SYSLRGX              -              stores information about compiled plan/pkgs including access paths

SYSUTILX             -              Have entry of utilities which we run on a system

Note : Commited work units only will be available in SYSCATALOG / DIRECTORY

LOGS

Logs will have entries with timestamps and RBA value for each entry mainly used for recovery

LOG STATUS

ACTIVE                                 -              in use

Archieve              -              offloading(old logs)

Archieve logs will reside in tapes often , depends on cost factor of shops.

Active logs must reside in DASD,to enable fast access.we can 32 active log dataset to a DB.

Dual Copy

                Each active log dataset will have a backup copy for the datace redundancy.Having a backup of existing datasets.

We can use force offload command to make active to archive logs.

Jobs should commit or offloading will not take place.So all active queries should comit before offloading.

BSDS

Boot Strap Data Set

·         Inventory of logs

·         It holds details about RBA range the archieve log datasets archieved.

·         We can use DSNJU004 to get information about logs.Its a separate physical datasets.

HLQ.BSDS01

HLQ.BSDS02                      

Utilities

·         Online utilities

·         Offline utilities (stand alone utilities)

Utilities will be provided by  IBM as well as different vendors .