Storage Sizes Installation Parms (DSNTIPC, DSNTIPE, DSNTIPE1)

This topic shows detailed information about "System Parameters - Storage Sizes Installation Parms (DSNTIPC, DSNTIPE, DSNTIPE1)".

This block shows the storage sizes calculated by the installation CLIST.

These space estimates do not account for cylinder rounding. Base requirements can be 10 to 20% higher depending on the DASD type. Most of the needed virtual storage is in extended private storage (including the buffer pool, the EDM pool, most of the code, and a significant amount of working storage).

STORAGE SIZES INSTALLATION PARMS (DSNTIPC,DSNTIPE,DSNTIPE1)    
---------------------------------------------------------------
MAX NO OF DATA SETS CONCURRENTLY IN USE (DSMAX).........100,000
EDM STATEMENT CACHE SIZE IN KB (EDMSTMTC)...............960,000
EDM DBD CACHE SIZE IN KB (EDMDBDC)......................136,771
EDM SKELETON POOL SIZE IN KB (EDM_SKELETON_POOL).........24,000
MAXIMUM SIZE OF EDM POOL IN BYTES (EDMPOOL)..........52,428,800
MAXIMUM SIZE OF SORT POOL IN BYTES (SRTPOOL).........40,960,000
MAX IN-MEMORY SORT SIZE (MAXSORT_IN_MEMORY).................N/A
MAXIMUM SIZE OF RID POOL IN KB (MAXRBLK)................200,000
MAX NO OF USERS CONCURRENTLY RUNNING IN DB2 (CTHREAD).......800
MAX NO OF CONCURRENT REMOTE ACTIVE CONNECTIONS (MAXDBAT)....600
MAX NO OF REMOTE CONNECTIONS (CONDBAT)....................1,800
MAX NO OF TSO CONNECTIONS (IDFORE)..........................300
MAX NO OF BATCH CONNECTIONS (IDBACK)........................400
MAXIMUM KEPT DYNAMIC STATEMENTS (MAXKEEPD)................5,000
MAX OPEN FILE REFS (MAXOFILR)...............................100
MANAGE REAL STORAGE (REALSTORAGE_MANAGEMENT)...............AUTO
MAXIMUM REAL STORAGE (REALSTORAGE_MAX)........................0
CONTRACT THREAD STORAGE (CONTSTOR)..........................YES
MANAGE THREAD STORAGE (MINSTOR).............................YES
LONG-RUNNING READER IN MINUTES (LRDRTHLD).....................0
DDL TIMEOUT FACTOR (DDLTOX)...................................1
INDEX CLEANUP THREADS (INDEX_CLEANUP_THREADS)...............N/A
3990 CACHE (SEQCACH)........................................SEQ

MAX NO OF DATA SETS CONCURRENTLY IN USE (DSMAX)

The maximum number of data sets that can be open at one time.

The practical limit can be less than the MVS limit of 32727, depending on available storage below the line.

Install parameter DSMAX on panel DSNTIPC, or ZPARM DSMAX in DSN6SPRM.

Field Name: QWP4DSMX

EDM STATEMENT CACHE SIZE IN KB (EDMSTMTC)

The size of the statement cache that can be used by the Environmental Descriptor Manager (EDM). This value is used at DB2 startup time as the minimum value. You can increase and subsequently decrease this value with the SET SYSPARM command. This value cannot be decreased below the value that is specified at DB2 startup. The CLIST calculates a statement cache size. This storage pool is located above the 2 GB bar.

The value used at DB2 startup time is either calculated by the CLIST based on input from other installation information or an override value.

For record trace, this value is shown in bytes. For other reports, the value is shown in kilobytes.

Install parameter EDM STATEMENT CACHE on panel DSNTIPC, or ZPARM EDMSTMTC in DSN6SPRM.

Field Name: QWP4ESTC

EDM DBD CACHE SIZE IN KB (EDMDBDC)

The minimum size of the DBD cache that can be used by the Environmental Descriptor Manager (EDM). This value is used at DB2 startup time as the minimum value. You can increase and subsequently decrease the value with the SET SYSPARM command. This value cannot be decreased below the value that is specified at DB2 startup. This storage pool is located above the 2 GB bar. The CLIST calculates the DBD cache size.

The value used at DB2 startup time is either calculated by the CLIST based on input from other installation information or an override value.

Install parameter EDM DBD CACHE on panel DSNTIPC, or ZPARM EDMDBDC in DSN6SPRM.

Field Name: QWP4EDBC

EDM SKELETON POOL SIZE IN KB (EDM_SKELETON_POOL)

The minimum size of the EDM pool for skeleton package and skeleton cursor tables. For record trace, this value is shown in bytes. For other reports, the value is shown in kilobytes.

Install parameter EDM SKELETON POOL SIZE on panel DSNTIPC or ZPARM EDM_SKELETON_POOL in DSN6SPRM.

Field Name: QWP4SKLC

MAXIMUM SIZE OF EDM POOL IN BYTES (EDMPOOL)

The size (in kilobytes) of the environmental descriptor manager (EDM) pool.

This can be the value calculated by the CLIST, based on input from previous panels, or the value entered in the Override column at installation time.

Install parameter EDMPOOL STORAGE SIZE on panel DSNTIPC, or ZPARM EDMPOOL in DSN6SPRM.

Field Name: QWP4EDPL

MAXIMUM SIZE OF SORT POOL IN BYTES (SRTPOOL)

Indicates the amount of storage needed for the sort pool.

This can be the value calculated by the CLIST, based on input from previous panels, or the value entered in the Override column at installation time.

Install parameter SORT POOL SIZE on panel DSNTIPC, or ZPARM SRTPOOL in DSN6SPRM.

Field Name: QWP4SPOL

MAX IN-MEMORY SORT SIZE (MAXSORT_IN_MEMORY)

The maximum amount of storage in kilobytes to allocate for sorting the results of each query that contains the order by clause, the group by clause, or both. This field corresponds to field MAX IN-MEMORY SORT SIZE in installation panel DSNTIPC. The ZPARM name is MAXSORT_IN_MEMORY in DSN6SPRM.

Field Name: QWP4MIMTS

MAXIMUM SIZE OF RID POOL IN KB (MAXRBLK)

The amount of storage needed for the RID pool.

This can be the value calculated by the CLIST, based on input from previous panels, or the value entered in the Override column at installation time.

When 0, DB2 does not use access paths or join methods that depend on RID pool storage.

Install parameter RID POOL SIZE on panel DSNTIPC, or ZPARM MAXRBLK in DSN6SPRM.

Field Name: QWP4RMAX

MAX NO OF USERS CONCURRENTLY RUNNING IN DB2 (CTHREAD)

The maximum number of allied threads (threads started at the local subsystem) that can be allocated concurrently.

Separate threads are created for each occurrence of the following:

• TSO user (whether running a DSN command or a DB2 request from QMF)
• Batch job (whether running a DSN command or a DB2 utility)
• IMS region that can access DB2
• Active CICS transaction that can access DB2
• Task connected to DB2 through the call attachment facility.

Install parameter MAX USERS on panel DSNTIPE, or ZPARM CTHREAD in DSN6SYSP.

Field Name: QWP1CT

MAX NO OF CONCURRENT REMOTE ACTIVE CONNECTIONS (MAXDBAT)

The maximum number of database access threads (DBATs) that can be active concurrently.

When this limit has been reached, DB2 uses the value of DDF THREADS on panel DSNTIPR to decide how to handle a new allocation request.

When DDF THREADS is ACTIVE and MAX REMOTE CONNECTED has not been reached, the allocation request is allowed but any further processing for the connection is queued waiting for an active database access thread to terminate.

When DDF THREADS is INACTIVE and MAX REMOTE CONNECTED has not been reached, the allocation request is allowed and is processed when DB2 can assign an unused database access thread slot to the connection.

The total number of threads accessing data concurrently is the sum of MAX USERS and MAX REMOTE ACTIVE. The maximum allowable value for this sum is 2000.

Install parameter MAX REMOTE ACTIVE on panel DSNTIPE, or ZPARM MAXDBAT in DSN6SYSP.

Field Name: QWP1RMT

MAX NO OF REMOTE CONNECTIONS (CONDBAT)

The maximum allowed number of concurrent remote connections.

When this limit is reached, any new connection request is rejected.

Install parameter MAX REMOTE CONNECTED on panel DSNTIPE, or ZPARM CONDBAT in DSN6SYSP.

Field Name: QWP1CDB

MAX NO OF TSO CONNECTIONS (IDFORE)

The maximum number of concurrent TSO foreground connections (QMF, DSN, DB2I, and SPUFI).

Each of the following is a separate user:

• Each TSO foreground user executing a DSN command.
• Each TSO foreground user connected to DB2 through the call attachment facility (CAF). This can include QMF users running in TSO foreground or user-written CAF applications running in TSO foreground.

When the number of TSO users attempting to access DB2 exceeds this limit, connection requests are rejected.

There is no subsystem parameter to control the maximum concurrent connections for IMS and CICS. These are controlled by using IMS and CICS facilities. For CICS attachment, the maximum number of connections to DB2 can be controlled using the resource control table (RCT) TYPE=INIT THRDMAX value.

Install parameter MAX TSO CONNECT on panel DSNTIPE, or ZPARM IDFORE in DSN6SYSP.

Field Name: QWP1IDF

MAX NO OF BATCH CONNECTIONS (IDBACK)

The maximum allowed number of concurrent connections for batch jobs and utilities. This includes:

• All batch jobs using QMF.
• All batch jobs using the DSN command processor.
• All tasks connected to DB2 through call attach facility (CAF) running in batch. This can include:
  • Batch jobs using QMF
  • APPC applications
  • TCP/IP FTP connections

When the number of batch jobs reaches this limit, further requests are rejected.

Install parameter MAX BATCH CONNECT on panel DSNTIPE, or ZPARM IDBACK in DSN6SYSP.

Field Name: QWP1IDB

MAXIMUM KEPT DYNAMIC STATEMENTS (MAXKEEPD)

Shows the total number of prepared dynamic SQL statements that are saved past a commit point.

0 means that prepared dynamic SQL statements are not saved past commit points.

Install parameter MAX KEPT DYN STMTS on panel DSNTIPE, or ZPARM MAXKEEPD in DSN6SPRM.

Field Name: QWP4MXKD

MAX OPEN FILE REFS (MAXOFILR)

The maximum number of concurrently open data sets for processing LOB file references.

Install parameter MAX OPEN FILE REFS on panel DSNTIPE or ZPARM MAXOFILR in DSN6SYSP.

Field Name: QWP1MOFR

MANAGE REAL STORAGE (REALSTORAGE_MANAGEMENT)

Specifies whether DB2® manages real storage consumption. This field corresponds to field MANAGE REAL STORAGE on installation panel DSNTIPE. The ZPARM name is REALSTORAGE_MANAGEMENT in DSN6SPRM.

Field Name: QWP4STMN

MAXIMUM REAL STORAGE (REALSTORAGE_MAX)

The maximum amount of real plus auxiliary storage that can be used.

A value of 0 is displayed for NOLIMIT.

The ZPARM name is REALSTORAGE_MAX in DSN6SPRM.

Field Name: QWP4RSMX

CONTRACT THREAD STORAGE (CONTSTOR)

In DB2 12 this field is a serviceability field.

Indicates whether DB2 returns unused thread storage at commit. Possible values are:

YES

DB2 checks threads at commit points and periodically returns unused storage to the system.

NO

DB2 does not check threads at commit points and returns acquired storage on deallocation.

Install parameter CONTRACT THREAD STG on panel DSNTIPE, or ZPARM CONTSTOR in DSN6SPRM.

Field Name: QWP4CONT

MANAGE THREAD STORAGE (MINSTOR)

In DB2 12 this field is a serviceability field.

Shows whether DB2 uses storage management to optimize the amount of working storage consumed by individual threads.

Install parameter MANAGE THREAD STORAGE on panel DSNTIPE, or ZPARM MINSTOR in DSN6SPRM.

For best performance, this parameter should be NO, meaning DB2 does not manage thread storage.

When YES, DB2 uses best fit algorithm to manage and assign thread storage. This can help on systems that have many long-running threads and that are constrained on DBM1 address space.

Field Name: QWP4MSTG

LONG-RUNNING READER IN MINUTES (LRDRTHLD)

Shows the number of minutes that a read claim can be held by an agent before DB2 reports it as a long-running reader. Valid values are 0 (default) through 1439.

Install parameter LONG-RUNNING READER on installation panel DSNTIPE, or ZPARM LRDRTHLD in DSN6SYSP.

Field Name: QWP4LRTH

DDL TIMEOUT FACTOR (DDLTOX)

Shows the time out factor of the SQL data definition. The time out value is the product of this value and the IRLMRWT value.

ZPARM name DDLTOX in DSN6SPRM.

Field Name: QWP4DDLTO

INDEX CLEANUP THREADS (INDEX_CLEANUP_THREADS)

The maximum number of threads that can be created to clean up pseudo-deleted index entries on a data sharing member of a subsystem. This field corresponds to field INDEX CLEANUP THREADS on installation panel DSNTIPE1. The ZPARM name is INDEX_CLEANUP_THREADS in DSN6SPRM.

Field Name: QWP4IXCU

3990 CACHE (SEQCACH)

Indicates whether DB2 prefetch uses sequential mode to read cached data from a 3990 controller. When BYPASS (default), DB2 prefetch bypasses the cache.

When SEQ, DB2 prefetch uses sequential access for read activity. There is a performance benefit using SEQ with DFSMS or DFP controls with newer 3990 caches.

Install parameter SEQUENTIAL CACHE on panel DSNTIPE, or ZPARM SEQCACH in DSN6SPRM.

Field Name: QWP4SCAC