Administration Guide

Database Configuration Parameter Summary

The following table lists the parameters in the database configuration file. When changing the database configuration parameters, consider the detailed information for the parameter.

The column "Performance Impact" in the following table provides an indication of the relative importance of each parameter as it relates to system performance. It is impossible for this column to apply accurately to all environments; you should view this information as a generalization.

• High -- indicates the parameter can have a significant impact on performance. You should consciously decide the values of these parameters; which, in some cases, will mean that you accept the default provided.
• Medium -- indicates the parameter can have some impact on performance. Your specific environment and needs will determine how much tuning effort should be focused on these parameters.
• Low -- indicates that the parameter has a less general or less significant impact on performance.
• None -- indicates that the parameter does not directly impact performance. While you do not have to tune these parameters for performance, they can be very important for other aspects of your system configuration, such as enabling communication support.

Table 54. Configurable Database Configuration Parameters

Parameter	Performance Impact	Additional Information
app_ctl_heap_sz	Medium	Application Control Heap Size (app_ctl_heap_sz)
applheapsz	Medium	Application Heap Size (applheapsz)
audit_buf_sz	Medium	Audit Buffer Size (audit_buf_sz)
autorestart	Low	Auto Restart Enable (autorestart)
avg_appls	High	Average Number of Active Applications (avg_appls)
buffpage	High (when active)	Buffer Pool Size (buffpage)
catalogcache_sz	Medium	Catalog Cache Size (catalogcache_sz)
chngpgs_thresh	High	Changed Pages Threshold (chngpgs_thresh)
copyprotect	None	Copy Protection Enable (copyprotect)
dbheap	Medium	Database Heap (dbheap)
dft_degree	High	Default Degree (dft_degree)
dft_extent_sz	Medium	Default Extent Size of Table Spaces (dft_extent_sz)
dft_loadrec_ses	Medium	Default Number of Load Recovery Sessions (dft_loadrec_ses)
dft_prefetch_sz	Medium	Default Prefetch Size (dft_prefetch_sz)
dft_queryopt	Medium	Default Query Optimization Class (dft_queryopt)
dft_refresh_age	Medium	Default Refresh Age (dft_refresh_age)
dft_sqlmathwarn	None	Continue upon Arithmetic Exceptions (dft_sqlmathwarn)
dir_obj_name	None	Object Name in DCE Namespace (dir_obj_name)
discover_db	Medium	Discover Database (discover_db)
dlchktime	Medium	Time Interval for Checking Deadlock (dlchktime)
dl_expint	None	Data Links Access Token Expiry Interval (dl_expint)
dl_num_copies	None	Data Links Number of Copies (dl_num_copies)
dl_time_drop	None	Data Links Time After Drop (dl_time_drop)
dl_token	Low	Data Links Token Algorithm (dl_token)
dl_upper	None	Data Links Token in Upper Case (dl_upper)
dyn_query_mgmt	Low	Dynamic SQL Query Management (dyn_query_mgmt)
estore_seg_sz	Medium	Extended Storage Memory Segment Size (estore_seg_sz)
indexrec	Medium	Index Re-creation Time (indexrec)
indexsort	Low (see ***)	Index Sort Flag (indexsort)
locklist	High when it affects escalation	Maximum Storage for Lock List (locklist)
locktimeout	Medium	Lock Timeout (locktimeout)
logbufsz	High	Log Buffer Size (logbufsz)
logfilsiz	Medium	Size of Log Files (logfilsiz)
logprimary	Medium	Number of Primary Log Files (logprimary)
logretain	Low	Log Retain Enable (logretain)
logsecond	Medium	Number of Secondary Log Files (logsecond)
maxappls	Medium	Maximum Number of Active Applications (maxappls)
maxfilop	Medium	Maximum Database Files Open per Application (maxfilop)
maxlocks	High when it affects escalation	Maximum Percent of Lock List Before Escalation (maxlocks)
mincommit	High	Number of Commits to Group (mincommit)
newlogpath	Low	Change the Database Log Path (newlogpath)
num_db_backups	None	Number of Database Backups (num_db_backups)
num_estore_segs	Medium	Number of Extended Storage Memory Segments (num_estore_segs)
num_freqvalues	Low	Number of Frequent Values Retained (num_freqvalues)
num_iocleaners	High	Number of Asynchronous Page Cleaners (num_iocleaners)
num_ioservers	High	Number of I/O Servers (num_ioservers)
num_quantiles	Low	Number of Quantiles for Columns (num_quantiles)
pckcachesz	High	Package Cache Size (pckcachesz)
rec_his_retentn	None	Recovery History Retention Period (rec_his_retentn)
seqdetect	High	Sequential Detection Flag (seqdetect)
softmax	Medium	Recovery Range and Soft Checkpoint Interval (softmax)
sortheap	High	Sort Heap Size (sortheap)
stat_heap_sz	Low	Statistics Heap Size (stat_heap_sz)
stmtheap	Medium	Statement Heap Size (stmtheap)
tsm_mgmtclass	None	Tivoli Storage Manager Management Class (tsm_mgmtclass)
tsm_nodename	None	Tivoli Storage Manager Node Name (tsm_nodename)
tsm_owner	None	Tivoli Storage Manager Owner Name (tsm_owner)
tsm_password	None	Tivoli Storage Manager Password (tsm_password)
userexit	Low	User Exit Enable (userexit)
util_heap_sz	Low	Utility Heap Size (util_heap_sz)
Note: Changing the indexsort parameter to a value other than the default can have a negative impact on the performance of creating indexes. You should always try to use the default for this parameter.

Table 55. Informational Database Configuration Parameters

Parameter	Additional Information
backup_pending	Backup Pending Indicator (backup_pending)
codepage	Code Page for the Database (codepage)
codeset	Codeset for the Database (codeset)
collate_info	Collating Information (collate_info)
country	Country code for the Database (country)
database_consistent	Database is Consistent (database_consistent)
database_level	Database Release Level (database_level)
log_retain_status	Log Retain Status Indicator (log_retain_status)
loghead	First Active Log File (loghead)
logpath	Location of Log Files (logpath)
multipage_alloc	MultiPage File Allocation Enabled (multipage_alloc)
numsegs	Default Number of SMS Containers (numsegs)
release	Configuration File Release Level (release)
restore_pending	Restore Pending (restore_pending)
rollfwd_pending	Roll Forward Pending Indicator (rollfwd_pending)
territory	Territory for the Database (territory)
user_exit_status	User Exit Status Indicator (user_exit_status)