Table 18. DB2 Database Configuration Parameters
Parameter
|
Explanation
|
Setting
|
DFT_DEGREE
|
Degree of parallelism (1=turn query parallelism off)
|
1
|
DFT_QUERYOPT
|
Default query optimization class
|
3
|
DBHEAP
|
Database heap (4 KB)
|
7429(32bit)
10000(64bit)
|
CATALOGCACHE_SZ
|
Catalog cache size (4 KB)
|
5558(32bit)
8000(64bit)
|
LOGBUFSZ
|
Log buffer size (4 KB)
|
256 (NT);
|
UTIL_HEAP_SZ
|
Utilities heap size (4 KB)
|
5000(32bit)
10000(64bit)
|
LOCKLIST
|
Max. storage for lock list (4 KB)
|
25000 (The setting should never be smaller than this, but may be increased.)
|
APP_CTL_HEAP_SZ
|
Max. applications control heap size (4 KB). Controls the number of users that can be included within one connection to the database.
|
900
For customers using Siebel connection pooling feature, for best scalability, increment the parameter by 1200 for each 10 users per connection.
|
SORTHEAP
|
Sort list heap (4 KB)
Lower values should be used for development environments; higher values for production. However, increasing this value can lead to insufficient memory on the DB server. Also this parameter may need to be set below the recommended range if you have a high number of Siebel users. Therefore, you need to always monitor DB server memory and performance to find the best setting for your environment.
|
1000-5000
|
STMTHEAP
|
SQL statement heap (4 KB)
|
8192
|
STAT_HEAP_SZ
|
Statistics heap size (4 KB)
|
14000(32bit)
16000(64bit)
|
MAXLOCKS
|
Percentage of lock lists per application
|
20(32bit)
30(64bit)
|
LOCKTIMEOUT
|
Lock timeout (sec.)
|
300
|
CHNGPGS_THRESH
|
Changed pages threshold
|
30
|
NUM_IOCLEANERS
|
Number of asynchronous page cleaners
|
Number of CPUs
|
INDEXSORT
|
Index sort flag
|
YES
|
SEQDETECT
|
Sequential detect flag
|
YES
|
DFT_PREFETCH_SZ
|
Default prefetch size (4 KB)
|
32
|
LOGRETAIN
|
Sequential or circular log files.
|
RECOVERY
Set this parameter to RECOVERY in a production environment. Otherwise, you will lose data should your database crash. When LOGRETAIN is set to RECOVERY, you must also activate USEREXIT or implement another method to manage the archived logs, so that LOGPATH does not fill up.
|
MAXAPPLS
|
Maximum number of active applications.
|
Based on twice the number of users.
|
AVG_APPLS
|
Average number of active applications.
|
Depends on the environment.
|
MAXFILOP
|
Maximum DB files open per application.
|
500
|
LOGFILSIZ
|
Log file size (4 KB).
|
20000
|
LOGPRIMARY
|
Number of primary log files.
|
25-50
The value of LOGPRIMARY and LOGSECOND together may not exceed 128.
|
LOGSECOND
|
Number of secondary log files.
|
Up to 103
The value of LOGPRIMARY and LOGSECOND together may not exceed 128.
|
SOFTMAX
|
Percent log file reclaimed before
soft checkpoint.
|
80
|
APPLHEAPSZ
|
Default application heap (4 KB).
|
2500
|
PCKCACHESZ
|
Package cache size (4 KB).
|
40000
|
NUM_IOSERVERS
|
Number of disks on which the database resides.
|
Number of disks
|
