ALTER SYSTEM
ALTER SYSTEM [SET { [ALLOW_PARTIAL_SN_RESULTS = {TRUE | FALSE} ] [BACKUP_DISK_IO_SLAVES =integer
DEFERRED] [BACKUP_TAPE_IO_SLAVES =integer
DEFERRED] [CACHE_INSTANCES =integer
] [CONTROL_FILE_RECORD_KEEP_TIME =integer
DEFERRED] [DB_BLOCK_CHECKPOINT_BATCH =integer
] [DB_BLOCK_CHECKSUM = {TRUE | FALSE} ] [DB_BLOCK_MAX_DIRTY_TARGET =integer
] [DB_FILE_MULTIBLOCK_READ_COUNT =integer
] [FIXED_DATE = {'DD_MM_YY’ | ‘YYYY_MM_DD_HH24_MI_SS'} ] [FREEZE_DB_FOR_FAST_INSTANCE_RECOVERY = {TRUE | FALSE } DEFERRED] [GC_DEFER_TIME =integer
] [GLOBAL_NAMES = {TRUE | FALSE} ] [HASH_MULTIBLOCK_IO_COUNT =integer
] [JOB_QUEUE_PROCESSES =integer
] [LICENSE_MAX_SESSIONS =integer
] [LICENSE_MAX_USERS =integer
] [LICENSE_SESSIONS_WARNING =integer
] [LOG_ARCHIVE_DUPLEX_DEST = 'text
' ] [LOG_ARCHIVE_MIN_SUCCEED_DEST =integer
] [LOG_CHECKPOINT_INTERVAL =integer
] [LOG_CHECKPOINT_TIMEOUT =integer
] [LOG_SMALL_ENTRY_MAX_SIZE =integer
] [MAX_DUMP_FILE_SIZE = {size
| UNLIMITED}] [MTS_DISPATCHERS = 'protocol
,integer
'] [MTS_SERVERS =integer
] [RESOURCE_LIMIT {TRUE | FALSE} ] [OBJECT_CACHE_MAX_SIZE_PERCENT =integer
] [OBJECT_CACHE_OPTIMAL_SIZE =integer
] [OPS_ADMIN_GROUP = 'text
' ] [PARALLEL_INSTANCE_GROUP = 'text
' ] [PARALLEL_TRANSACTION_RESOURCE_TIMEOUT =integer
] [PLSQL_V2_COMPATIBILITY = {TRUE | FALSE} ] [REMOTE_DEPENDENCIES_MODE = {TIMESTAMP | SIGNATURE} ] [RESOURCE_LIMIT = {TRUE | FALSE} ] [SCAN_INSTANCES =integer
] [SORT_AREA_SIZE =integer
] [SORT_AREA_RETAINED_SIZE =integer
] [SORT_DIRECT_WRITES = {AUTO | TRUE | FALSE} ] [SORT_READ_FAC =integer
] [SORT_WRITE_BUFFERS =integer
] [SORT_WRITE_BUFFER_SIZE =integer
] [SPIN_COUNT =integer
] [TEXT_ENABLED = {TRUE | FALSE} ] [TIMED_STATISTICS = {TRUE | FALSE} ] [TIMED_OS_STATISTICS =integer
] [TRANSACTION_AUDITING = {TRUE | FALSE} DEFERRED] [USER_DUMP_DEST = 'dirname
'] } [ARCHIVE_LOG [THREADinteger
] { [START [TO 'destination
'] ] [STOP] [SEQinteger
[TO 'destination
'] ] [CHANGEinteger
[TO 'destination
'] ] [CURRENT [TO 'destination
'] ] [GROUPinteger
[TO 'destination
'] ] [LOGFILE 'filename
' [TO 'destination
'] ] [NEXT [TO 'destination
'] ] [ALL [TO 'destination
'] ] } [CHECKPOINT {GLOBAL | LOCAL} ] [CHECK DATAFILES {GLOBAL | LOCAL} ] [DISCONNECT SESSION 'sid_integer.session_integer
' POST_TRANSACTION] [ENABLE DISTRIBUTED RECOVERY] [DISABLE DISTRIBUTED RECOVERY] [ENABLE RESTRICTED SESSION] [DISABLE RESTRICTED SESSION] [FLUSH SHARED_POOL] [SWITCH LOGFILE] [KILL SESSION 'sid_integer
,session_integer
']
Makes dynamic changes to the database instance.
Indicates that one or more system-level keywords will follow.
Allows you to override the INIT.ORA parameter ALLOW_PARTIAL_SN_RESULTS for the current instance. A value of TRUE allows results to be retrieved in the GV$ views even if a slave process cannot be created for one or more instances.
Allows you to override the INIT.ORA parameter BACKUP_DISK_IO_SLAVES for the current instance. Specifies the number of I/O slaves used to back up, copy, or restore database files to disk.
Allows you to override the INIT.ORA parameter BACKUP_TAPE_IO_SLAVES for the current instance. Specifies the number of I/O slaves used to back up, copy, or restore database files to tape.
Specifies the number of instances in a Parallel Server environment that will cache a table. Note that this parameter is expected to be obsolete in a future release of Oracle.
Allows you to override the INIT.ORA parameter CONTROL_FILE_RECORD_KEEP_TIME for the current instance. Specifies the minimum number of days a reusable entry is stored in the control file. If necessary, the control file will expand to include enough records.
Allows you to override the INIT.ORA parameter DB_BLOCK_CHECKPOINT_BATCH for this instance. Specifies a number of additional database buffer blocks that can be written out by DBWR when it writes buffers to disk, advancing checksum processing.
Allows you to override the INIT.ORA parameter DB_BLOCK_CHECKSUM for the current instance. Specifies whether DBWR is to calculate and record a checksum with every database buffer block written. The checksum is then calculated and compared on reads. The default is FALSE.
Allows you to override the INIT.ORA parameter DB_BLOCK_MAX_DIRTY_READ_COPY for this instance. Specifies a target maximum number of dirty blocks. When this value is reached, DBWR starts writing additional blocks in an attempt to bring the number of dirty blocks down.
Allows you to override the INIT.ORA parameter DB_FILE_MULTIBLOCK_READ_COUNT for the current instance. This specifies the target number of database block buffers to read in at a time during sequential scans of a table.
Allows you to override the INIT.ORA parameter FIXED_DATE for this instance. This provides a fixed value that is always returned by SYSDATE for testing.
Allows you to override the INIT.ORA parameter FREEZE_DB_FOR_FAST_INSTANCE_RECOVERY for this database. A value of TRUE freezes the entire database during an instance recovery. This causes the database to appear to hang for current users, but makes the instance recovery complete faster. FALSE does not freeze the database, and DEFERRED defers it.
Allows you to override the INIT.ORA parameter GC_DEFER_TIME for this instance. Specifies how many hundredths of a second the instance will wait or defer before writing out buffers when a forced write is signaled from another instance.
Specifies whether global naming will be enforced (TRUE) or not enforced (FALSE).
Specifies the number of database blocks to be read or written during hash I/O operations.
Allows you to override the INIT.ORA parameter JOB_QUEUE_PROCESSES for this instance. Specifies the maximum number of SNP background processes. The allowed values are between and 36.
Specifies the maximum number of sessions permitted on this instance. A value of indicates that there is no limit.
Specifies the maximum number of users in this database. A value of indicates that there is no limit.
Specifies the maximum number of sessions permitted on this instance before a warning message is written to the alert file. A value of indicates that there is no limit.
Overrides the INIT.ORA parameter LOG_ARCHIVE_DUPLEX_DEST for this instance. Specifies an additional archive log destination that is to be written to when redo logs are archived.
Overrides the INIT.ORA parameter LOG_ARCHIVE_MIN_SUCCEED_DEST for this instance. Specifies the minimum number of archive file writes that have to succeed before the archive is considered complete.
Overrides the INIT.ORA parameter LOG_CHECKPOINT_INTERVAL for this instance. Specifies the number of redo log blocks that can be written before a checkpoint is forced.
Overrides the INIT.ORA parameter LOG_CHECKPOINT_TIMEOUT for this instance. Specifies in seconds the maximum amount of time between checkpoints. This can be used to force a checkpoint on a periodic basis even when there is minimal database activity.
Overrides the INIT.ORA parameter LOG_SMALL_ENTRY_MAX_SIZE for this instance. Specifies the largest copy of log buffers that can be performed using the log allocation latch without resorting to using the log buffer copy latch.
Allows you to override the INIT.ORA parameter MAX_DUMP_FILE_SIZE for the current instance. The integer specified is the maximum number of operating system blocks to be used for a trace file. A value of UNLIMITED specifies that no limit is to be imposed.
Changes the number of dispatcher processes for the named protocol. The database must be open to issue this command.
Changes the minimum number of shared MTS server processes.
Specifies whether resource limits will be enforced (TRUE) or not enforced (FALSE).
Allows you to override the INIT.ORA parameter OBJECT_CACHE_MAX_SIZE_PERCENT for this instance. This value is the percent by which the object cache can exceed the optimal size. When this value is exceeded, the cache will be reduced to the optimal size.
Allows you to override the INIT.ORA parameter OBJECT_CACHE_OPTIMAL_SIZE for this instance. This specifies the size to which the object cache is reduced when it exceeds its maximum value.
Allows you to override the INIT.ORA parameter OPS_ADMIN_GROUP for this instance. In a Parallel Server environment, the instances can be divided into one or more groups to ease administration. The effect of this parameter is to limit the instances reflected in the GV$ views.
Allows you to override the INIT.ORA parameter PARALLEL_INSTANCE_GROUP for this instance. This specifies the instance groups to which parallel query slaves can be spawned.
Allows you to override the INIT.ORA parameter PARALLEL_TRANSACTION_RESOURCE_TIMEOUT for this instance. This Parallel Server parameter specifies how many seconds a session will wait on an object locked by another session.
Specifies whether to support, for compatibility reasons, PL/SQL V2 constructs that are no longer supported in Oracle8 PL/SQL V3.
Allows you to override the INIT.ORA parameter REMOTE_DEPENDENCIES_MODE for this session. This specifies how PL/SQL will treat dependencies upon remote procedures:
Allows you to override the INIT.ORA parameter RESOURCE_LIMIT for this instance. A value of TRUE enables enforcement of resource limits as specified in user profiles.
Specifies how many instances are to participate in parallelized operations. This parameter will become obsolete in the next major release of Oracle.
Allows you to override the INIT.ORA parameter SORT_AREA_SIZE for this session. This specifies the amount of memory allocated out of the PGA (the SGA in an MTS environment) for sorts.
Allows you to override the INIT.ORA parameter SORT_AREA_RETAINED_SIZE for this session. This is the maximum size that the sort area in the PGA retains between the sort completing and fetching the last row from the sort area.
Allows you to override the INIT.ORA parameter SORT_DIRECT_WRITES for this session. The valid values are:
Allows you to override the INIT.ORA parameter SORT_READ_FAC for this instance. This parameter provides Oracle with a ratio indicating relative disk performance. The default is operating system dependent.
Allows you to override the INIT.ORA parameter SORT_WRITE_BUFFERS for this instance. This parameter specifies the number of sort buffers to use when SORT_DIRECT_WRITES is set to TRUE.
Allows you to override the INIT.ORA parameter SORT_WRITE_BUFFER_SIZE for this instance. This parameter specifies the size of the sort write buffer to use when SORT_DIRECT_WRITES is set to TRUE.
Allows you to override the INIT.ORA parameter SPIN_COUNT for this instance. This parameter specifies the number of times a process will wait on a latch before sleeping.
Allows you to override the INIT.ORA parameter TEXT_ENABLED for this instance. This parameter determines whether to enable the CONTAINS clause in the Oracle ConText option or the Oracle ConText cartridge.
Allows you to override the INIT.ORA parameter TIMED_STATISTICS for this instance. When this parameter is set to TRUE, Oracle will call system services to determine the length of time required for most operations.
Allows you to override the INIT.ORA parameter TIMED_OS_STATISTICS for this instance. Specifies the number of seconds between calls to collect operating system statistics.
Allows you to override the INIT.ORA parameter TRANSACTION_AUDITING for the current instance. A value of TRUE causes Oracle to write information into the redo log to identify the user and instance responsible for individual modifications to the database. FALSE causes Oracle not to write information, and DEFERRED defers the operation.
Allows you to override the INIT.ORA parameter USER_DUMP_DEST for the current instance. Specifies a directory in which trace files are written.
Manually archives redo log file groups; enables or disables automatic archiving as follows:
Specifies the thread containing the redo log file group to be archived. This parameter is only required when running the Parallel Server option in parallel mode.
Specifies the log sequence number of the redo log file group to be manually archived. The database must be mounted but may be open or closed to issue this command.
Manually archives the online redo log file group containing the redo log entry with the system change number (SCN) specified by integer. If the SCN is the current log group, a log switch is performed. The database must be open to use this parameter.
Manually forces a log switch and archives the current redo log file group. The database must be open to use this parameter.
Manually archives the online redo log file group with the specified GROUP value, which can be found in DBA_LOG_FILES. The database must be mounted but may be open or closed to issue this command.
Manually archives the online redo log file group containing the log file member identified by filename. The database must be mounted but may be open or closed to issue this command.
Manually archives the next online redo log file group that is full but has not yet been archived. The database must be mounted but may be open or closed to issue this command.
Manually archives all online redo log file groups that are full but have not been archived. The database must be mounted but may be open or closed to issue this command.
Causes Oracle to perform a checkpoint. The database may be open or closed to issue this command. You may specify:
Verifies access to online datafiles. The database may be open or closed to issue this command. You may specify:
Disconnects a session in the current instance using SID and SESSION# from V$SESSION. The current transaction is allowed to complete, and, since the session is only disconnected, it becomes a candidate for application failover (if configured) to another instance in a Parallel Server environment.
Specifies that distributed recovery is to be enabled and—in a single-process environment—used to initiate distributed recovery.
Specifies that distributed recovery is to be disabled.
Allows only users with the RESTRICTED SESSION privilege to log on to the instance.
Allows any user with the CREATE SESSION privilege to log on to the instance.
Clears all data from the instance shared pool. The database may be dismounted or mounted, open or closed, to issue this command.
Causes Oracle to switch redo log file groups.
Terminates a session using SID and SESSION# from V$SESSION.
You must have the ALTER SYSTEM privilege to issue this command. In addition, the ARCHIVE LOG command requires that you have the OSDBA or OSOPER role enabled. Except as noted, the database may be mounted and open to issue these commands.
The following example changes the number of dispatcher processes for TCP to 10 and for DECNet to 8:
ALTER SYSTEM SET MTS_DISPATCHERS = 'TCP,10' MTS_DISPATCHERS = 'DECnet,8'
The following example sets the maximum number of sessions to 100, and sets the warning threshold to 80:
ALTER SYSTEM SET LICENSE_MAX_SESSIONS = 100 LICENSE_SESSIONS_WARNING = 80
The following example archives log sequence number 123 to the specified location:
ALTER SYSTEM ARCHIVE LOG SEQ 123 TO '/disk09/oracle/archive'