Siebel Installation Guide for Microsoft Windows: Servers, Mobile Web Clients, Tools > Guidelines for Configuring the RDBMS > Configuring IBM DB2 UDB for Siebel Applications >

Guidelines for the DB2 UDB Database Manager Configuration Parameters


You can set the database configuration parameters using the update database manager configuration command of the DB2 Command Line Processor or using the DB2 Control Center.

See the IBM DB2 technical documentation for more information on modifying the database configuration parameters.

Table 5 describes DB2 database manager configuration parameters that differ from the default settings. Set these parameters for each DB2 instance. Use the configuration information in Table 5 for the listed parameters. For parameters not listed in this table, accept the default settings.

Table 5.  DB2 Database Manager Configuration Parameters
Parameter
Explanation
Setting/Comment

SHEAPTHRES

Sort heap threshold (4 KB)

200000

Deployments with 3,000 or more concurrent users and using over 5 GB of RAM can increase this to 300000.

DIR_CACHE

Directory cache support

YES

ASLHEAPSZ

Application support layer heap size

15

RQRIOBLK

Maximum requester I/O block size (bytes)

65535

MON_HEAP_SZ

Database monitor heap size (4 KB)

128 (minimum)

QUERY_HEAP_SZ

Query heap size (4 KB)

16384

KEEPFENCED

Keep Fenced process (replaces KEEPDARI in DB2 v7)

YES

KEEPDARI

Keep DARI process (only for DB2 v7)

YES

MAXAGENTS

Maximum number existing agents

20000 (minimum)

NUM_INITAGENTS

Initial number agents in pool

10

NUM_POOLAGENTS

Number of agents in the agent pool kept active at all times

80

MAX_COORDAGENTS

Maximum number coordinating agents

MAXAGENTS

INDEXREC

Index re-creation time

RESTART

MAX_QUERYDEGREE

Maximum query degree of parallelism

Between 1 and 6

INTRA_PARALLEL

Enable intra-partition parallelism

NO

DB2set Parameters

Use the db2set command to set the parameters (for example, db2set DB2_HASH_JOIN = NO) referenced in Table 6.

Under Windows, you access this command through the DB2 Command Line Processor, accessible from the DB2 for Windows.

Table 6.  db2set Parameters
Parameter
Explanation
Setting

DB2_HASH_JOIN

Turns off hash joins in the optimizer.

NO

DB2_RR_TO_RS

Improves DB2 v7 performance with Siebel eBusiness Applications. This parameter does not apply to DB2 v8.

NOTE:  Set to YES only in production environment servers.

YES

DB2_CORRELATED_PREDICATES

When set to YES, the optimizer is able to determine whether predicates in a query are related, which permits DB2 to calculate the filter factor more accurately.

YES

DB2_INDEX_2BYTEVARLEN

If you use DB2 v7, set this parameter to ON. Otherwise, you will not be able to create indexes with columns greater than 255 bytes. You do not need to set this parameter for DB2 v8 because DB2 v8 supports type-2 indexes.

ON

DB2_PIPELINED_PLANS

Tells the DB2 optimizer to favor pipeline execution plans—plans that are left deep and have no temporary result sets.

ON

DB2_INTERESTING_KEYS

Limits the number of execution plans generated by the DB2 optimizer.

ON

DB2_PARALLEL_IO

Useful when using RAID devices. For more information, see your DB2 vendor documentation.

*

DB2_STRIPED_CONTAINERS

Useful when using RAID devices. For more information, see your DB2 vendor documentation.

ON

DB2_NO_PKG_LOCK

To bind the Siebel package with siebbind, this package must be off.

OFF

Siebel Installation Guide for Microsoft Windows: Servers, Mobile Web Clients, Tools