The following parameters are database parameters that determine special properties of the database instance:
_EVENT_ALIVE_CYCLE |
The time in seconds of an event cycle |
_MAX_MESSAGE_FILES |
Maximum number of trace files that can be open simultaneously |
_MAXEVENTS |
Maximum number of events stored by the kernel in the cache for processing by the Database Manager |
_UNICODE |
Parameter for creating a UNICODE-compliant database You can no longer change this database parameter after you have created the database instance. |
CAT_CACHE_SUPPLY |
Size of catalog cache memory for all user tasks in pages |
DATE_TIME_FORMAT |
System default for the date and time format By entering the appropriate information in the database tool (such as the standard_date_mask in the Loader), or by using SQL statements (such as datetimeformat), each user can change the date and time format for a session. For information about the possible values and syntax, see Date and Time Format. |
DEADLOCK_DETECTION |
Maximum search level for deadlock detection. Any deadlocks that are not detected at this search level are only resolved by the parameter REQUEST_TIMEOUT. If DEADLOCK_DETECTION = 0, deadlock detection is disabled. |
DEFAULT_CODE |
System default for the code attribute Applies only to column values of the data type CHAR[ACTER], VARCHAR, and LONG[VARCHAR]. |
DEVNO_BIT_COUNT |
See DEVNO_BIT_COUNT |
DIAG_HISTORY_NUM |
Number of histories in the <diag_history_path> directory |
DIAG_HISTORY_PATH |
Directory <diag_history_path> for the histories of log files The default value is DIAGHISTORY in the run directory of the database instance. |
HS_DELAY_TIME_<NNN> |
For hot standby systems only; delay in seconds after which the standby component NNN redoes changes that have already been done in the master component |
HS_NODE_<NNN> |
Computer name/address of the hot standby component NNN. HSS_NODE_001 is the default for the master component of the standby system. |
HS_STORAGE_DLL |
For hot standby systems only; name of the library through which the memory management system is addressed The default is libhsscopy. |
HS_SYNC_INTERVAL |
For hot standby systems only; minimum period of time (in seconds) between two master component commands for synchronizing the standby components Any value between 0 and 36000 seconds is allowed. The default is 50. |
JOIN_MAXTAB_LEVEL4 |
Parameter for calculating the join sequence algorithm; see JOIN_SEARCH_LEVEL |
JOIN_MAXTAB_LEVEL9 |
Parameter for calculating the join sequence algorithm; see JOIN_SEARCH_LEVEL |
JOIN_SEARCH_LEVEL |
Algorithm for the join sequence search; see JOIN_SEARCH_LEVEL |
KERNELDIAGSIZE |
Size of the log file knldiag in KB |
LOAD_BALANCING_CHK |
Interval (in seconds) after which the database system checks whether load balancing is needed 0 £ LOAD_BALANCING_CHK < 600 The default is 0 (load balancing deactivated). |
LOG_BACKUP_TO_PIPE |
Specifies whether log backup in pipes is permitted |
LOG_IO_QUEUE |
Size of the log queue in pages |
LRU_FOR_SCAN |
Specifies whether the entire data cache is used for scans |
MAXRGN_REQUEST |
Maximum number of attempts a task should make to access a region If this number is exceeded, the task lets another task access the CPU as long as it belongs to the same user kernel thread. |
MAXSERVERTASKS |
Determines the number of server tasks that are available, for example, for backups and recoveries |
MP_RGN_LOOP |
Maximum number of times a task may attempt to access a critical section that has been locked by another task If this number is exceeded, the accessing task changes its status “Waiting”. |
OFFICIAL_NODE |
For cluster systems only; official name of the database within the cluster system Defined by the system administrator. |
OPTIM_INV_ONLY |
Determines whether the Index Only strategy is used for joins |
OPTIM_MAX_MERGE |
Specifies the change of the optimizer algorithm of the strategies for merging index lists If the number of pages of an index that need to be merged exceeds the value specified in OPTIM_MAX_MERGE, this index will not be used for an index merging strategy. |
REQUEST_TIMEOUT |
Maximum wait before a lock is released (in seconds) This parameter limits the amount of time you have to wait until a lock is lifted by other users for all database sessions. If a lock request cannot be satisfied within the time defined here, a message is returned to the waiting database session. Any changes made previously in the transactions are undone. |
SEQUENCE_CACHE |
The size of the sequence cache in pages |
SESSION_TIMEOUT |
Timeout value for database sessions in seconds |
SET_VOLUME_LOCK |
Specifies whether a volume can be added or whether it is locked Possible values are Yes and No; the default is Yes. Yes: When a volume is added, a lock is set that prevents the same volume from being added again, which would cause errors in the system configuration. No: No lock is set when a volume is added. |
UTILITY_PROT_SIZE |
Size of the log file dbm.utl in pages |
You can display the full list of special database parameters for your database instance and additional information about these parameters using the Database Manager.