1.4 Changing Parameter Values in a Parameter File
You can change the value of a parameter in a parameter file in several ways.
-
By editing an initialization parameter file
In most cases, the new value takes effect the next time you start an instance of the database.
-
By issuing an
ALTER SYSTEM SET ... SCOPE=SPFILE
statement to update a server parameter file -
By issuing an
ALTER SYSTEM RESET
statement to clear an initialization parameter value.See Also:
Oracle Database Administrator’s Guide for more information about using the
ALTER SYSTEM RESET
statement to clear initialization parameter values
1.4.1 Parameters by Functional Category
This section lists initialization parameters by their functional category.
-
ANSI Compliance
-
Backup and Restore
-
BFILEs
-
Buffer Cache and I/O
- CLIENT_RESULT_CACHE_LAG
- CLIENT_RESULT_CACHE_SIZE
- DB_nK_CACHE_SIZE
- DB_BIG_TABLE_CACHE_PERCENT_TARGET
- DB_BLOCK_BUFFERS
- DB_BLOCK_SIZE
- DB_CACHE_ADVICE
- DB_CACHE_SIZE
- DB_FILE_MULTIBLOCK_READ_COUNT
- DB_KEEP_CACHE_SIZE
- DB_RECYCLE_CACHE_SIZE
- DB_WRITER_PROCESSES
- DBWR_IO_SLAVES
- DISK_ASYNCH_IO
- DNFS_BATCH_SIZE
- FILESYSTEMIO_OPTIONS
- READ_ONLY_OPEN_DELAYED
- RESULT_CACHE_MAX_RESULT
- RESULT_CACHE_MAX_SIZE
- RESULT_CACHE_MODE
-
Cursors and Library Cache
-
Database/Instance Identification
-
Diagnostics and Statistics
-
Distributed, Replication
-
File Locations, Names, and Sizes
-
Globalization
-
Java
-
Job Queues
-
License Limits
-
Memory
- INMEMORY_ADG_ENABLED
- INMEMORY_AUTOMATIC_LEVEL
- INMEMORY_CLAUSE_DEFAULT
- INMEMORY_EXPRESSIONS_USAGE
- INMEMORY_FORCE
- INMEMORY_MAX_POPULATE_SERVERS
- INMEMORY_OPTIMIZED_ARITHMETIC
- INMEMORY_QUERY
- INMEMORY_SIZE
- INMEMORY_TRICKLE_REPOPULATE_SERVERS_PERCENT
- INMEMORY_VIRTUAL_COLUMNS
- MEMOPTIMIZE_POOL_SIZE
- MEMORY_MAX_TARGET
- MEMORY_TARGET
-
Miscellaneous
- AQ_TM_PROCESSES
- ASM_IO_PROCESSES
- ASM_PREFERRED_READ_FAILURE_GROUPS
- AWR_SNAPSHOT_TIME_OFFSET
- COMPATIBLE
- DB_INDEX_COMPRESSION_INHERITANCE
- ENABLE_DNFS_DISPATCHER
- FIXED_DATE
- INSTANCE_ABORT_DELAY_TIME
- LDAP_DIRECTORY_SYSAUTH
- MAX_DATAPUMP_JOBS_PER_PDB
- MAX_STRING_SIZE
- MULTISHARD_QUERY_DATA_CONSISTENCY
- PRIVATE_TEMP_TABLE_PREFIX
- SHRD_DUPL_TABLE_REFRESH_RATE
- SPATIAL_VECTOR_ACCELERATION
- UNIFORM_LOG_TIMESTAMP_FORMAT
- XML_DB_EVENTS
-
Multitenant Architecture
- AUTOTASK_MAX_ACTIVE_PDBS
- AWR_PDB_AUTOFLUSH_ENABLED
- COMMON_USER_PREFIX
- CONTAINERS_PARALLEL_DEGREE
- DB_PERFORMANCE_PROFILE
- DEFAULT_SHARING
- ENABLE_AUTOMATIC_MAINTENANCE_PDB
- ENABLED_PDBS_ON_STANDBY
- EXTERNAL_KEYSTORE_CREDENTIAL_LOCATION
- MAX_IOPS
- MAX_MBPS
- MAX_PDBS
- NONCDB_COMPATIBLE
- PDB_FILE_NAME_CONVERT
- PDB_LOCKDOWN
- PDB_OS_CREDENTIAL
- SGA_MIN_SIZE
-
Networking
-
Objects and LOBs
-
OLAP
-
Optimizer
- APPROX_FOR_AGGREGATION
- APPROX_FOR_COUNT_DISTINCT
- APPROX_FOR_PERCENTILE
- OPTIMIZER_ADAPTIVE_PLANS
- OPTIMIZER_ADAPTIVE_REPORTING_ONLY
- OPTIMIZER_ADAPTIVE_STATISTICS
- OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES
- OPTIMIZER_DYNAMIC_SAMPLING
- OPTIMIZER_FEATURES_ENABLE
- OPTIMIZER_IGNORE_HINTS
- OPTIMIZER_IGNORE_PARALLEL_HINTS
- OPTIMIZER_INDEX_CACHING
- OPTIMIZER_INDEX_COST_ADJ
- OPTIMIZER_INMEMORY_AWARE
- OPTIMIZER_MODE
- OPTIMIZER_SECURE_VIEW_MERGING
- OPTIMIZER_USE_PENDING_STATISTICS
- OPTIMIZER_USE_SQL_PLAN_BASELINES
- QUERY_REWRITE_ENABLED
- QUERY_REWRITE_INTEGRITY
- STAR_TRANSFORMATION_ENABLED
-
Parallel Execution
-
PL/SQL
-
PL/SQL Compiler
-
SGA Memory
-
Oracle RAC
-
Redo Logs, Archiving, and Recovery
- ADG_ACCOUNT_INFO_TRACKING
- CONTROL_FILE_RECORD_KEEP_TIME
- DATA_GUARD_SYNC_LATENCY
- DB_CREATE_ONLINE_LOG_DEST_n
- DB_RECOVERY_FILE_DEST
- DB_RECOVERY_FILE_DEST_SIZE
- DB_UNRECOVERABLE_SCN_TRACKING
- FAST_START_MTTR_TARGET
- LOG_ARCHIVE_CONFIG
- LOG_ARCHIVE_DEST_n
- LOG_ARCHIVE_DEST_STATE_n
- LOG_ARCHIVE_DUPLEX_DEST
- LOG_ARCHIVE_FORMAT
- LOG_ARCHIVE_MAX_PROCESSES
- LOG_ARCHIVE_MIN_SUCCEED_DEST
- LOG_ARCHIVE_TRACE
- LOG_BUFFER
- LOG_CHECKPOINT_INTERVAL
- LOG_CHECKPOINT_TIMEOUT
- LOG_CHECKPOINTS_TO_ALERT
- RECOVERY_PARALLELISM
- REDO_TRANSPORT_USER
- REMOTE_RECOVERY_FILE_DEST
-
Resource Manager
-
Security and Auditing
- ALLOW_GLOBAL_DBLINKS
- ALLOW_GROUP_ACCESS_TO_SGA
- AUDIT_FILE_DEST
- AUDIT_SYS_OPERATIONS
- AUDIT_SYSLOG_LEVEL
- AUDIT_TRAIL
- COMMIT_LOGGING
- COMMIT_WAIT
- DBFIPS_140
- ENCRYPT_NEW_TABLESPACES
- O7_DICTIONARY_ACCESSIBILITY
- OS_AUTHENT_PREFIX
- OS_ROLES
- OUTBOUND_DBLINK_PROTOCOLS
- RDBMS_SERVER_DN
- REMOTE_LOGIN_PASSWORDFILE
- REMOTE_OS_AUTHENT
- REMOTE_OS_ROLES
- SEC_CASE_SENSITIVE_LOGON
- SEC_MAX_FAILED_LOGIN_ATTEMPTS
- SEC_PROTOCOL_ERROR_FURTHER_ACTION
- SEC_PROTOCOL_ERROR_TRACE_ACTION
- SEC_RETURN_SERVER_RELEASE_BANNER
- SQL92_SECURITY
- TDE_CONFIGURATION
- UNIFIED_AUDIT_SGA_QUEUE_SIZE
- WALLET_ROOT
-
Sessions and Processes
-
Shared Server Architecture
-
Standby Database
-
Temporary Sort Space
-
Transactions
-
Undo Management
1.4.2 Modifiable Parameters
You can modify some initialization parameters using the ALTER SESSION
or ALTER SYSTEM
statements while an instance is running.
Use the following syntax to modify initialization parameters:
ALTER SESSION SET parameter_name = value ALTER SYSTEM SET parameter_name = value [DEFERRED]
Whenever a parameter is modified using the ALTER SYSTEM
statement, the Oracle Database records the statement that modifies the parameter in the alert log.
The ALTER SESSION
statement changes the value of the specified parameter for the duration of the session that invokes the statement. The value of the parameter does not change for other sessions in the instance. The value of the following initialization parameters can be changed with ALTER SESSION
:
- APPROX_FOR_AGGREGATION
- APPROX_FOR_COUNT_DISTINCT
- APPROX_FOR_PERCENTILE
- AQ_TM_PROCESSES
- ASM_DISKSTRING
- ASM_POWER_LIMIT
- COMMIT_LOGGING
- COMMIT_WAIT
- COMMIT_WRITE
- CONTAINERS_PARALLEL_DEGREE
- CREATE_STORED_OUTLINES
- CURSOR_BIND_CAPTURE_DESTINATION
- CURSOR_INVALIDATION
- CURSOR_SHARING
- DB_BLOCK_CHECKING
- DB_CREATE_FILE_DEST
- DB_CREATE_ONLINE_LOG_DEST_n
- DB_FILE_MULTIBLOCK_READ_COUNT
- DB_FILE_NAME_CONVERT
- DB_INDEX_COMPRESSION_INHERITANCE
- DB_SECUREFILE
- DB_UNRECOVERABLE_SCN_TRACKING
- DDL_LOCK_TIMEOUT
- DEFAULT_SHARING
- DEFERRED_SEGMENT_CREATION
- DST_UPGRADE_INSERT_CONV
- ENABLE_DDL_LOGGING
- GLOBAL_NAMES
- HASH_AREA_SIZE
- HEAT_MAP
- INMEMORY_CLAUSE_DEFAULT
- INMEMORY_QUERY
- JAVA_JIT_ENABLED
- LOG_ARCHIVE_DEST_n
- LOG_ARCHIVE_DEST_STATE_n
- LOG_ARCHIVE_MIN_SUCCEED_DEST
- MAX_DUMP_FILE_SIZE
- MULTISHARD_QUERY_DATA_CONSISTENCY
- NLS_CALENDAR
- NLS_COMP
- NLS_CURRENCY
- NLS_DATE_FORMAT
- NLS_DATE_LANGUAGE
- NLS_DUAL_CURRENCY
- NLS_ISO_CURRENCY
- NLS_LANGUAGE
- NLS_LENGTH_SEMANTICS
- NLS_NCHAR_CONV_EXCP
- NLS_NUMERIC_CHARACTERS
- NLS_SORT
- NLS_TERRITORY
- NLS_TIMESTAMP_FORMAT
- NLS_TIMESTAMP_TZ_FORMAT
- OBJECT_CACHE_MAX_SIZE_PERCENT
- OBJECT_CACHE_OPTIMAL_SIZE
- OLAP_PAGE_POOL_SIZE
- OPTIMIZER_ADAPTIVE_PLANS
- OPTIMIZER_ADAPTIVE_REPORTING_ONLY
- OPTIMIZER_ADAPTIVE_STATISTICS
- OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES
- OPTIMIZER_DYNAMIC_SAMPLING
- OPTIMIZER_FEATURES_ENABLE
- OPTIMIZER_IGNORE_HINTS
- OPTIMIZER_IGNORE_PARALLEL_HINTS
- OPTIMIZER_INDEX_CACHING
- OPTIMIZER_INDEX_COST_ADJ
- OPTIMIZER_INMEMORY_AWARE
- OPTIMIZER_MODE
- OPTIMIZER_USE_INVISIBLE_INDEXES
- OPTIMIZER_USE_PENDING_STATISTICS
- OPTIMIZER_USE_SQL_PLAN_BASELINES
- PARALLEL_DEGREE_LIMIT
- PARALLEL_DEGREE_POLICY
- PARALLEL_FORCE_LOCAL
- PARALLEL_INSTANCE_GROUP
- PARALLEL_MIN_DEGREE
- PARALLEL_MIN_PERCENT
- PARALLEL_MIN_TIME_THRESHOLD
- PDB_FILE_NAME_CONVERT
- PDB_LOCKDOWN
- PLSCOPE_SETTINGS
- PLSQL_CCFLAGS
- PLSQL_CODE_TYPE
- PLSQL_DEBUG
- PLSQL_OPTIMIZE_LEVEL
- PLSQL_V2_COMPATIBILITY
- PLSQL_WARNINGS
- QUERY_REWRITE_ENABLED
- QUERY_REWRITE_INTEGRITY
- RECYCLEBIN
- REMOTE_DEPENDENCIES_MODE
- RESULT_CACHE_MODE
- RESULT_CACHE_REMOTE_EXPIRATION
- RESUMABLE_TIMEOUT
- SESSION_CACHED_CURSORS
- SKIP_UNUSABLE_INDEXES
- SMTP_OUT_SERVER
- SORT_AREA_RETAINED_SIZE
- SORT_AREA_SIZE
- SPATIAL_VECTOR_ACCELERATION
- SQL_TRACE
- SQLTUNE_CATEGORY
- STAR_TRANSFORMATION_ENABLED
- STATISTICS_LEVEL
- TEMP_UNDO_ENABLED
- TIMED_OS_STATISTICS
- TIMED_STATISTICS
- TRACEFILE_IDENTIFIER
- WORKAREA_SIZE_POLICY
- XML_DB_EVENTS
The ALTER SYSTEM
statement without the DEFERRED
keyword modifies the global value of the parameter for all sessions in the instance, for the duration of the instance (until the database is shut down). The value of the following initialization parameters can be changed with ALTER SYSTEM
:
- ALLOW_GLOBAL_DBLINKS
- APPROX_FOR_AGGREGATION
- APPROX_FOR_COUNT_DISTINCT
- APPROX_FOR_PERCENTILE
- AQ_TM_PROCESSES
- ASM_IO_PROCESSES
- AWR_SNAPSHOT_TIME_OFFSET
- ARCHIVE_LAG_TARGET
- ASM_DISKGROUPS
- ASM_DISKSTRING
- ASM_POWER_LIMIT
- ASM_PREFERRED_READ_FAILURE_GROUPS
- AUTOTASK_MAX_ACTIVE_PDBS
- AWR_PDB_AUTOFLUSH_ENABLED
- BACKGROUND_CORE_DUMP
- BACKGROUND_DUMP_DEST
- CIRCUITS
- COMMIT_LOGGING
- COMMIT_WAIT
- COMMIT_WRITE
- CONNECTION_BROKERS
- CONTAINERS_PARALLEL_DEGREE
- CONTROL_FILE_RECORD_KEEP_TIME
- CONTROL_MANAGEMENT_PACK_ACCESS
- CORE_DUMP_DEST
- CPU_COUNT
- CREATE_STORED_OUTLINES
- CURSOR_BIND_CAPTURE_DESTINATION
- CURSOR_INVALIDATION
- CURSOR_SHARING
- DATA_GUARD_SYNC_LATENCY
- DATA_TRANSFER_CACHE_SIZE
- DB_nK_CACHE_SIZE
- DB_BIG_TABLE_CACHE_PERCENT_TARGET
- DB_BLOCK_CHECKING
- DB_BLOCK_CHECKSUM
- DB_CACHE_ADVICE
- DB_CACHE_SIZE
- DB_CREATE_FILE_DEST
- DB_CREATE_ONLINE_LOG_DEST_n
- DB_FILE_MULTIBLOCK_READ_COUNT
- DB_FLASH_CACHE_FILE
- DB_FLASH_CACHE_SIZE
- DB_FLASHBACK_RETENTION_TARGET
- DB_INDEX_COMPRESSION_INHERITANCE
- DB_KEEP_CACHE_SIZE
- DB_LOST_WRITE_PROTECT
- DB_RECOVERY_FILE_DEST
- DB_RECOVERY_FILE_DEST_SIZE
- DB_RECYCLE_CACHE_SIZE
- DB_SECUREFILE
- DB_UNRECOVERABLE_SCN_TRACKING
- DDL_LOCK_TIMEOUT
- DEFAULT_SHARING
- DEFERRED_SEGMENT_CREATION
- DG_BROKER_CONFIG_FILEn
- DG_BROKER_START
- DIAGNOSTIC_DEST
- DISPATCHERS
- DST_UPGRADE_INSERT_CONV
- ENABLE_AUTOMATIC_MAINTENANCE_PDB
- ENABLE_DDL_LOGGING
- ENABLE_GOLDENGATE_REPLICATION
- ENABLED_PDBS_ON_STANDBY
- ENCRYPT_NEW_TABLESPACES
- FAL_CLIENT
- FAL_SERVER
- FAST_START_MTTR_TARGET
- FAST_START_PARALLEL_ROLLBACK
- FILE_MAPPING
- FIXED_DATE
- FORWARD_LISTENER
- GLOBAL_NAMES
- GLOBAL_TXN_PROCESSES
- HEAT_MAP
- HS_AUTOREGISTER
- INMEMORY_ADG_ENABLED
- INMEMORY_AUTOMATIC_LEVEL
- INMEMORY_CLAUSE_DEFAULT
- INMEMORY_EXPRESSIONS_USAGE
- INMEMORY_FORCE
- INMEMORY_MAX_POPULATE_SERVERS
- INMEMORY_OPTIMIZED_ARITHMETIC
- INMEMORY_QUERY
- INMEMORY_SIZE
- INMEMORY_TRICKLE_REPOPULATE_SERVERS_PERCENT
- INMEMORY_VIRTUAL_COLUMNS
- JAVA_JIT_ENABLED
- JAVA_POOL_SIZE
- JOB_QUEUE_PROCESSES
- LARGE_POOL_SIZE
- LDAP_DIRECTORY_ACCESS
- LICENSE_MAX_SESSIONS
- LICENSE_MAX_USERS
- LICENSE_SESSIONS_WARNING
- LISTENER_NETWORKS
- LOCAL_LISTENER
- LOG_ARCHIVE_CONFIG
- LOG_ARCHIVE_DEST
- LOG_ARCHIVE_DEST_n
- LOG_ARCHIVE_DEST_STATE_n
- LOG_ARCHIVE_DUPLEX_DEST
- LOG_ARCHIVE_MAX_PROCESSES
- LOG_ARCHIVE_MIN_SUCCEED_DEST
- LOG_ARCHIVE_TRACE
- LOG_CHECKPOINT_INTERVAL
- LOG_CHECKPOINT_TIMEOUT
- LOG_CHECKPOINTS_TO_ALERT
- LONG_MODULE_ACTION
- MAX_DATAPUMP_JOBS_PER_PDB
- MAX_DISPATCHERS
- MAX_DUMP_FILE_SIZE
- MAX_IDLE_TIME
- MAX_IOPS
- MAX_MBPS
- MAX_PDBS
- MAX_SHARED_SERVERS
- MEMOPTIMIZE_POOL_SIZE
- MEMORY_TARGET
- MULTISHARD_QUERY_DATA_CONSISTENCY
- NLS_LENGTH_SEMANTICS
- NLS_NCHAR_CONV_EXCP
- OFS_THREADS
- OPEN_CURSORS
- OPTIMIZER_ADAPTIVE_PLANS
- OPTIMIZER_ADAPTIVE_REPORTING_ONLY
- OPTIMIZER_ADAPTIVE_STATISTICS
- OPTIMIZER_CAPTURE_SQL_PLAN_BASELINES
- OPTIMIZER_DYNAMIC_SAMPLING
- OPTIMIZER_FEATURES_ENABLE
- OPTIMIZER_IGNORE_HINTS
- OPTIMIZER_IGNORE_PARALLEL_HINTS
- OPTIMIZER_INDEX_CACHING
- OPTIMIZER_INDEX_COST_ADJ
- OPTIMIZER_INMEMORY_AWARE
- OPTIMIZER_MODE
- OPTIMIZER_SECURE_VIEW_MERGING
- OPTIMIZER_USE_INVISIBLE_INDEXES
- OPTIMIZER_USE_PENDING_STATISTICS
- OPTIMIZER_USE_SQL_PLAN_BASELINES
- OUTBOUND_DBLINK_PROTOCOLS
- PARALLEL_ADAPTIVE_MULTI_USER
- PARALLEL_DEGREE_LIMIT
- PARALLEL_DEGREE_POLICY
- PARALLEL_FORCE_LOCAL
- PARALLEL_INSTANCE_GROUP
- PARALLEL_MAX_SERVERS
- PARALLEL_MIN_DEGREE
- PARALLEL_MIN_SERVERS
- PARALLEL_MIN_TIME_THRESHOLD
- PARALLEL_SERVERS_TARGET
- PARALLEL_THREADS_PER_CPU
- PDB_LOCKDOWN
- PGA_AGGREGATE_LIMIT
- PGA_AGGREGATE_TARGET
- PLSCOPE_SETTINGS
- PLSQL_CCFLAGS
- PLSQL_CODE_TYPE
- PLSQL_DEBUG
- PLSQL_OPTIMIZE_LEVEL
- PLSQL_V2_COMPATIBILITY
- PLSQL_WARNINGS
- QUERY_REWRITE_ENABLED
- QUERY_REWRITE_INTEGRITY
- RECOVERY_PARALLELISM
- REDO_TRANSPORT_USER
- REMOTE_DEPENDENCIES_MODE
- REMOTE_LISTENER
- REMOTE_RECOVERY_FILE_DEST
- RESOURCE_LIMIT
- RESOURCE_MANAGER_CPU_ALLOCATION
- RESOURCE_MANAGER_PLAN
- RESULT_CACHE_MAX_RESULT
- RESULT_CACHE_MAX_SIZE
- RESULT_CACHE_MODE
- RESULT_CACHE_REMOTE_EXPIRATION
- RESUMABLE_TIMEOUT
- SEC_CASE_SENSITIVE_LOGON
- SEC_PROTOCOL_ERROR_FURTHER_ACTION
- SEC_PROTOCOL_ERROR_TRACE_ACTION
- SERVICE_NAMES
- SGA_MIN_SIZE
- SGA_TARGET
- SHADOW_CORE_DUMP
- SHARED_POOL_SIZE
- SHARED_SERVER_SESSIONS
- SHARED_SERVERS
- SHRD_DUPL_TABLE_REFRESH_RATE
- SKIP_UNUSABLE_INDEXES
- SMTP_OUT_SERVER
- SPATIAL_VECTOR_ACCELERATION
- SPFILE
- SQL_TRACE
- SQLTUNE_CATEGORY
- STANDBY_FILE_MANAGEMENT
- STANDBY_PDB_SOURCE_FILE_DBLINK
- STANDBY_PDB_SOURCE_FILE_DIRECTORY
- STAR_TRANSFORMATION_ENABLED
- STATISTICS_LEVEL
- STREAMS_POOL_SIZE
- TDE_CONFIGURATION
- TEMP_UNDO_ENABLED
- THREAD
- TIMED_OS_STATISTICS
- TIMED_STATISTICS
- TRACE_ENABLED
- UNDO_RETENTION
- UNDO_TABLESPACE
- UNIFORM_LOG_TIMESTAMP_FORMAT
- USE_DEDICATED_BROKER
- USER_DUMP_DEST
- WORKAREA_SIZE_POLICY
- XML_DB_EVENTS
The ALTER SYSTEM ... DEFERRED
statement does not modify the global value of the parameter for existing sessions, but the value will be modified for future sessions that connect to the database. The value of the following initialization parameters can be changed with ALTER SYSTEM ... DEFERRED
:
1.4.3 Displaying Current Parameter Values
You can use the SQL*Plus SHOW PARAMETERS
statement to see the current settings for initialization parameters.
1.4.4 Parameters You Should Not Specify in the Parameter File
You should not specify these types of parameters in your parameter files:
-
Parameters that you never alter unless instructed to do so by Oracle to resolve a problem
-
Derived parameters, which normally do not need altering because their values are calculated automatically by the Oracle database server
1.4.5 When Parameters Are Set Incorrectly
When a parameter is set incorrectly, the effect can be different for different parameters, or based on how low or high the parameter is set.
Some parameters have a minimum setting below which an Oracle instance will not start. For other parameters, setting the value too low or too high may cause Oracle to perform badly, but it will still run. Also, Oracle may convert some values outside the acceptable range to usable levels.
If a parameter value is too low or too high, or you have reached the maximum for some resource, then Oracle returns an error. Frequently, you can wait a short while and retry the operation when the system is not as busy. If a message occurs repeatedly, then you should shut down the instance, adjust the relevant parameter, and restart the instance.