Oracle Undocumented Underscore Startup Parameters
Version 21c
Page 1 of 5

General Information
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Purpose The "undocumented" underscore parameters are parameters officially undocumented and unsupported by Oracle but that may be utilized, after receiving permission from Oracle Support to address specific issues such as bugs.

The current page is numbered 1 of 5 and has been posted to the Library. Additional pages and sections will be published as they are completed.
Query for undocumented initialization parameters set pagesize 35
set linesize 150
col NAME format a40
col VALUE format a20
col DESCRIPTION format a60
set pause on
set pause 'Hit enter to continue'

SELECT x.ksppinm NAME, y.ksppstvl VALUE, x.ksppdesc DESCRIPTION
FROM x$ksppi x, x$ksppcv y
WHERE x.inst_id = userenv('Instance')
AND y.inst_id = userenv('Instance')
AND x.indx = y.indx
AND SUBSTR(LOWER(x.ksppinm),1,1) = '_'
ORDER BY 1;
Page Index
Sections
Adaptive Queries Diagnostics / Statistics Network & Connectivity
ADDM Distributed Replication NLS Parameters
Advanced Queuing Exadata Optimizer
Archive Logging File Locations PL/SQL
Active Session History Flashback RAC
Automatic Storage Management Group By Result Cache
Automatic Workload Repository Hang Manager Security
Backup & Restore In-Memory Tracing
Block Change Tracking Instance Identification Transactions
Compression I/O Undo
Data Guard Memory Undocumented
DB Block Miscellaneous  
 
Adaptive Queries
_ADAPTIVE_DIRECT_READ
Default: TRUE
Adaptive Direct Read
_adaptive_direct_read=FALSE
_ADAPTIVE_DIRECT_WRITE
Default: TRUE
Adaptive Direct Write
_adaptive_direct_write=FALSE
_ADAPTIVE_FETCH_ENABLED
Default: TRUE
Enable/disable adaptive fetch in parallel group by
_adaptive_fetch_enabled=FALSE
_ADAPTIVE_LOG_FILE_SYNC_HIGH_SWITCH_FREQ _THRESHOLD
Default: 3
Threshold for frequent log file sync mode switches (per minute)
_adaptive_log_file_sync_high_switch_freq=5
_ADAPTIVE_LOG_FILE_SYNC_POLL_AGGRESSIVENESS
Default: 0
Polling interval selection bias (conservative=0, aggressive=100)
_adaptive_log_file_sync_poll_aggressiveness=1
_ADAPTIVE_LOG_FILE_SYNC_SAMPLING_COUNT
Default: 128
Evaluate post/wait versus polling every N writes
_adaptive_log_file_sync_sampling_count=96
_ADAPTIVE_LOG_FILE_SYNC_SAMPLING_TIME
Default: 3
Evaluate post/wait versus polling every N seconds
_adaptive_log_file_sync_sampling_time=5
_ADAPTIVE_LOG_FILE_SYNC_SCHED_DELAY_WINDOW
Default: 60
Window (in seconds) for measuring average scheduling delay
_adaptive_log_file_sync_sched_delay_window=90
_ADAPTIVE_LOG_FILE_SYNC_USE_POLLING_THRESHOLD
Default: 200
Ratio of redo synch time to expected poll time as a percentage
_adaptive_log_file_sync_use_polling_threshold=180
_ADAPTIVE_LOG_FILE_SYNC_USE_POSTWAIT _THRESHOLD
Default: 50
Percentage of foreground load from when post/wait was last used
_adaptive_log_file_sync_use_postwait_threshold=60
_ADAPTIVE_LOG_FILE_SYNC_USE_POSTWAIT
_THRESHOLD_AGING
Default: 1001
Permille of foreground load from when post/wait was last used
_adaptive_log_file_sync_use_postwait_threshold_aging=512
_ADAPTIVE_SCALABLE_LOG_WRITER_DISABLE_WORKER _THRESHOLD
Default: 50
Percentage of overlap across multiple outstanding writes
_adaptive_scalable_log_writer_disable_worker_threshold=60
_ADAPTIVE_SCALABLE_LOG_WRITER_ENABLE_WORKER _AGING
Default: 999900
Per million of redo gen rate when LGWR workers were last used
_adaptive_scalable_log_writer_enable_worker_aging=1200000
_ADAPTIVE_SCALABLE_LOG_WRITER_ENABLE_WORKER _THRESHOLD
Default: 200
Increase in redo generation rate as a percentage
_adaptive_scalable_log_writer_enable_worker_threshold=240
_ADAPTIVE_SCALABLE_LOG_WRITER_SAMPLING_COUNT
Default: 128
Evaluate single versus scalable LGWR every N writes
_adaptive_scalable_log_writer_sampling_count=256
_ADAPTIVE_SCALABLE_LOG_WRITER_SAMPLING_TIME
Default: 3
Evaluate single versus scalable LGWR every N seconds
_adaptive_scalable_log_writer_sampling_time=6
_ADAPTIVE_WINDOW_CONSOLIDATOR_ENABLED
Default: TRUE
Enable/disable adaptive window consolidator PX plan
_adaptive_window_consolidator_enabled=FALSE
_BSLN_ADAPTIVE_THRESHOLDS_ENABLED
Default: TRUE
Adaptive Thresholds Enabled
_bsln_adaptive_thresholds_enabled=FALSE
_DB_DW_SCAN_ADAPTIVE_COOLING
Default: FALSE
Ff TRUE, enable adaptive DW scan cooling
_db_dw_scan_adaptive_cooling=TRUE
_DB_DW_SCAN_MAX_SHADOW_COUNT
Default: 5
DW Scan adaptive cooling max shadow count
_db_dw_scan_max_shadow_count=6
_DISABLE_ADAPTIVE_SHRUNK_AGGREGATION
Default: FALSE
Adaptive shrunk aggregation
_disable_adaptive_shrunk_aggregation=TRUE
_OPTIMIZER_ADAPTIVE_CURSOR_SHARING
Default: TRUE
Optimizer adaptive cursor sharing
_optimizer_adaptive_cursor_sharing=FALSE
_OPTIMIZER_ADAPTIVE_PLAN_CONTROL
Default: 0
Internal controls for adaptive plans
_optimizer_adaptive_plan_control=1
_OPTIMIZER_ADAPTIVE_PLANS_CONTINUOUS
Default: FALSE
Enable continuously adaptive plans
_optimizer_adaptive_plans_continuous=TRUE
_OPTIMIZER_ADAPTIVE_PLANS_ITERATIVE
Default: 0
Enable iterative adaptive plans
_optimizer_adaptive_plan_iterative=TRUE
_OPTIMIZER_ADAPTIVE_RANDOM_SEED
Default: 0
Random seed for adaptive plans
_optimizer_adaptive_random_seed=0
_OPTIMIZER_NLJ_HJ_ADAPTIVE_JOIN
Default: TRUE
Allow adaptive NL Hash joins
_optimizer_nlj_hj_adaptive_join=FALSE
_OPTIMIZER_STRANS_ADAPTIVE_PRUNING
Default: TRUE
Allow adaptive pruning of star transformation bitmap trees
_optimizer_strans_adaptive_pruning=FALSE
 
ADDM
_ADDM_AUTO_ACTIONS_ENABLED
Default: TRUE
Determines if ADDM can automatically implement its recommendations
_addm_auto_actions_enabled=FALSE
_ADDM_AUTO_ENABLE
Default: TRUE
Governs whether ADDM gets run automatically after every AWR snapshot
_addm_auto_enable=FALSE
_ADDM_SKIPRULES
Default: None Defined
Comma-separated list of ADDM nodes to skip
TBD
_ADDM_VERSION_CHECK
Default: TRUE
Governs whether ADDM checks the input AWR snapshot version
_addm_auto_enable=FALSE
 
Advanced Queuing (AQ) & Streams
_AQSHARDED_CACHE_LIMIT
Default: 0
Limit for cached enqueue/dequeue operations
_aqsharded_cache_limit=1
_AQ_ADDPT_BATCH_SIZE
Default: 1
Add PT batch size
_aq_addpt_batch_size=5
_AQ_DQ_PREFETCH_SIZ
Default: 5
AQ PT DQ prefech size
_aq_addpt_batch_size=5
_AQ_DLY_BKT
Default: 2
Delay Bucket Size
_aq_dly_bkt=10
_AQ_DQ_PREFETCH_SIZ
Default: 5
AQ PT DQ prefech Size
_aq_dq_prefetch_siz=10
_AQ_DLY_BKT
Default: 0
Deq blocks in cache
_aq_dqblocks_in_cache=1
_AQ_DROPPT_BATCH_SIZE
Default: 5
Drop PT batch Size
_aq_droppt_batch_size=10
_AQ_FREE_LIST_POOLS
Default: 10
State object and transaction memory pools
_aq_free_list_pools=6
_AQ_INIT_SHARDS
Default: 5
Minimum enqueue shards per queue at an instance
_aq_init_shards=2
_AQ_IPC_MAX_SLAVE
Default: 10
Maximum number of slaves for knlpipcm
_aq_ipc_max_slave=12
_AQ_LATENCY_ABSOLUTE_THRESHOLD
Default: 300
Absolute threshold greater than average latency
_aq_latency_absolute_threshold=240
_AQ_LATENCY_RELATIVE_THRESHOLD
Default: 100
Relative threshold of average latency
_aq_latency_relative_threshold=80
_AQ_LB_CYCLE
Default: 120
Time(seconds) between consecutive AQ load balancing efforts
_aq_lb_cycle=96
_AQ_LB_GARBAGE_COL_INTERNAL
Default: 600
Delay Bucket Size
_aq_lb_garbage_col_interval=480
_AQ_LB_STATS_COLLECT_CYCLE
Default: 45
Time(seconds) between consecutive AQ load statistics collection
_aq_lb_stats_collect_cycle=60
_AQ_LB_SUBHT_BKT_LTCH
Default: 600
AQ LB subscriber ht bucket latches
_aq_lb_subht_bkt_ltch=48
_AQ_LB_SUBHT_ELM_LTCH
Default: 600
AQ LB subscriber ht element latches
_aq_lb_subht_elm_ltch=192
_AQ_LOOKBACK_SIZE
Default: 60
AQ PT look back size
_aq_loopback_size=72
_AQ_MAX_PDB_CLOSE_MSG
Default: 1
Max Number of AQ Recovery Messages when PDB is closed
_aq_max_pdb_close_msg=0
_AQ_MAX_SCAN_DELAY
Default: 1500
Maximum allowable scan delay for AQ indexes and IOTs
_aq_max_scan_delay=1200
_AQ_OPT_BACKGROUND_ENABLED
Default: TRUE
AQ: OPT Operations Background enabled
_aq_opt_background_enabled=FALSE
_AQ_OPT_ENABLED
Default: TRUE
AQ: OPT Operations enabled
_aq_opt_enabled=FALSE
_AQ_OPT_FUDGE_FACTOR
Default: 500
AQ: OPT Fudge Factor for pre-fretching
_aq_opt_fudge_factor=480
_AQ_OPT_MIN_EVICT_MEMORY
Default: 0
AQ: OPT LWM memory for eviction to stop
_aq_opt_min_evict_memory_=1
_AQ_OPT_PREEVICT_DOP
Default: 3
AQ: OPT Background: PreEvict Degree Of Parallelism
_aq_opt_preevict_dop=1
_AQ_OPT_PREFETCH_DOP
Default: 3
AQ: OPT Background: Prefetch Degree Of Parallelism
_aq_opt_prefetch_dop=5
_AQ_OPT_PREFETCH_HORIZON
Default: 60
AQ: OPT horizon for pre-fretching
_aq_opt_prefetch_horizon=72
_AQ_OPT_STAT_WINDOW
Default: 21600
AQ: OPT Subscriber Statistics Window Size
_aq_opt_stat_window=18000
_AQ_OPT_STOP_STAT
Default: FALSE
AQ: OPT Stop Collection of Subscriber Statistics
_aq_opt_stop_stat=TRUE
_AQ_PT_PROCESSES
Default: 10
Partition background processes
_aq_pt_processes=18
_AQ_PT_SHRINK_FREQUENCY
Default: 1450
PT shrink window size
_aq_pt_shrink_frequency=1200
_AQ_PT_STATISTICS_WINDOW
Default: 60
PT statistics sample window size
_aq_pt_statistics_window=90
_AQ_QT_PREFETCH_SIZE
Default: 5
AQ PT QT prefech size
_aq_qt_prefetch_size=10
_AQ_RETRY_TIMEOUTS
Default: 0
Retry timeouts
_aq_retry_timeouts=1
_AQ_SCRAMBLED_DEQLOG
Default: 1
Scrambled deqlog
_aq_scrambled_deqlog=0
_AQ_SHARD_BITMAP_CHILD_LATCHES
Default: 32
Bitmap child latches
_aq_shard_bitmap_child_latches=48
_AQ_SHARD_CHILD_LATCHES
Default: 512
Shard child latches
_aq_shard_child_latches=384
_AQ_SHARD_PRTY_LATCHES
Default: 16
Shard priority child latches
_aq_shard_prty_latches=24
_AQ_SHARD_RETRY_CHILD_LATCHES
Default: 32
Retry child latches
_aq_shard_retry_child_latches=24
_AQ_SHARD_SUB_CHILD_ELEM_LATCHES
Default: 1024
Subscriber element child latches
_aq_shard_sub_child_elem_latches=784
_AQ_SHARD_SUB_CHILD_LATCHES
Default: 512
Subscriber child latches
_aq_shard_sub_child_latches=384
_AQ_SHARD_TXN_CHILD_LATCHES
Default: 128
Txn child latches
_aq_shard_txn_child_latches=96
_AQ_STOP_BACKGROUNDS
Default: FALSE
Stop all AQ background processes
_aq_stop_backgrounds=TRUE
_AQ_STREAMING_THRESHOLD
Default: 10485760
Large payload threshold size
_aq_streaming_threshold=15697920
_AQ_SUBSHARDS_PER_DQPARTITION
Default: 1
SubShards Per Dequeue Partition
_aq_subshards_per_dqpartition=3
_AQ_SUBSHARDS_PER_QPARTITION
Default: 1
SubShards Per Q Partition
_aq_subshards_per_qpartition=3
_AQ_SUBSHARD_SIZE
Default: 20000
Sub Shard Size
_aq_subshard_size=18000
_AQ_TM_DEQCOUNTINTERVAL
Default: 0
Dequeue count interval for Time Managers to cleanup DEQ IOT BLOCKS
_aq_tm_deqcountinterval=1
_AQ_TM_SCANLIMIT
Default: 0
Scan limit for Time Managers to clean up IOT
_aq_tm_scanlimit=1
_AQ_TM_STATISTICS_DURATION
Default: 0
Statistics collection window duration
_aq_tm_statistics_duration=1
_AQ_TRUNCPT_BATCH_SIZE
Default: 1
Trunc PT batch Size
_aq_truncpt_batch_size=0
_AQ_TXN_HT_SZ
Default: 1024
Message cache transaction hash table size
_aq_txn_ht_sz=768
_AQ_UNCACHED_STATS
Default: 0
Uncached Stats
_aq_uncached_stats=1
_AQ_X_MODE
Default: 1
AQ - cross mode
_aq_x_msg_size=0
_AQ_X_MSG_SIZE
Default: 32768
AQ cross single message buffer size
_aq_x_msg_size=36384
_DISABLE_STREAMS_DIAGNOSTICS
Default: 0
Streams diagnostics
_disable_streams_diagnostics=1
_DISABLE_STREAMS_POOL_AUTO_TUNING
Default: FALSE
Disable streams pool auto tuning
_disable_streams_pool_auto_tuning=TRUE
_STREAMS_POOL_MAX_SIZE
Default: 0
Streams pool maximum size when auto SGA enabled
_streams_pool_max_size=4M
_STREAMS_POOL_SIZE
Default: 33554432
Actual size in bytes of streams pool
_streams_pool_size=4M
 
Archive Logging
_ARCH_COMPRESSION
Default: TRUE
Archive compression enabled
_arch_compression=FALSE
_ARCH_COMPRESS_CHECKSUMS
Default: FALSE
Enable/disable row checksums for archive compressed blocks
_arch_compress_checksums=TRUE
_ARCH_COMP_DEC_BLOCK_CHECK_DUMP
Default: 1
Decompress archive compression blocks for checking and dumping
_arch_comp_dec_block_check_dump=0
_ARCH_COMP_DBG_SCAN
Default: 0
archive compression scan debug
_arch_comp_dbg_scan=1
_ARCH_IO_SLAVES
Default: 0
ARCH I/O slaves
_arch_io_slaves=??
_ARCH_SIM_MODE
Default: 0
Change behavior of local archiving
_arch_sim_mode=1
 
Active Session History
_ASH_COMPRESSION_ENABLE
Default: TRUE
To enable or disable string compression in ASH
Range of values: {TRUE | FALSE}
_ash_compression_enable=TRUE
_ASH_DISK_FILTER_RATIO
Default: 10
Ratio of the number of in-memory samples to the number of samples actually written to disk
_ash_disk_filter_ratio=10
_ASH_DISK_WRITE_ENABLE
Default: TRUE
To enable or disable Active Session History flushing
Range of values: {TRUE | FALSE}
_ash_disk_write_enable=TRUE
_ASH_DUMMY_TEST_PARAM
Default: 0
Oracle internal dummy ASH parameter used ONLY for testing!
_ash_dummy_test_param=0
_ASH_EFLUSH_TRIGGER
Default: 66
The percentage above which if the in-memory ASH is full the emergency flusher will be triggered
_ash_eflush_trigger=66
_ASH_ENABLE
Default: TRUE
To enable or disable Active Session sampling and flushing
Range of values: {TRUE | FALSE}
_ash_enable=FALSE
_ASH_MIN_MMNL_DUMP
Default: 90
Minimum Time interval passed to consider MMNL Dump
_ash_min_mmnl_dump=90
_ASH_PROGRESSIVE_FLUSH_INTERVAL
Default: 300
ASH Progressive Flush interval in secs
_ash_progressive_flush_interval=360
_ASH_SAMPLE_ALL
Default: FALSE
To enable or disable sampling every connected session including ones waiting for idle waits
Range of values: {TRUE | FALSE}
_ash_sample_all=TRUE
_ASH_SAMPLING_INTERVAL
Default: 1000
Time interval between two successive Active Session samples in millisecs
_ash_sampling_interval=2000
_ASH_SIZE
Default: 1048618
To set the size of the in-memory Active Session History buffers
_ash_size=10485760
 
Automatic Storage Management (ASM)
_ASMSID
Default: asm
ASM instance id
_asmsid=asmnode1
_ASM_ACCESS
Default: AUTO
ASM File access mechanism
TBD
_ASM_ACCESS_ASSUME_LOCAL
Default: FALSE
Assume IOS client is in the same cluster as IOS
_asm_access_assume_local=TRUE
_ASM_ACD_CHUNKS
Default: 1
Initial ACD chunks created
TBD
_ASM_ADMIN_WITH_SYSDBA
Default: FALSE
Does the sysdba role have administrative privileges on ASM?
TBD
_ASM_ALLOWDEGENERATEMOUNTS
Default: FALSE
Allow force-mounts of DGs w/o proper quorum
 
_ASM_ALLOW_APPLIANCE_DROPDISK_NOFORCE
Default: FALSE
Allow DROP DISK/FAILUREGROUP NOFORCE on ASM Appliances
TBD
_ASM_ALLOW_DANGEROUS_UNPROTECTED_VOLUMES
Default: FALSE
Disable checking for unprotected volumes in mirrored disk groups
TBD
_ASM_ALLOW_DGNAME_SPECIAL_CHARS
Default: FALSE
Enable the use of special characters in diskgroup names
TBD
_ASM_ALLOW_FOREIGN_SITEGUIDS
Default: NULL
Disable checking for foreign siteguid on a given node
TBD
_ASM_ALLOW_LVM_RESILVERING
Default: TRUE
Enable disk resilvering for external redundancy
TBD
_ASM_ALLOW_OLDER_CLIENTS
Default: FALSE
Allow older clients to connect to the ASM server
_asm_allow-older_clients=TRUE
_ASM_ALLOW_ONLY_RAW_DISKS
Default: TRUE
Discovery only raw devices
TBD
_ASM_ALLOW_PREPARE_SPLIT
Default: TRUE
Allow database prepare and split in non-appliance mode
TBD
_ASM_ALLOW_SMALL_MEMORY_TARGET
Default: FALSE
Allow a small memory_target for ASM instances
TBD
_ASM_ALLOW_SYSTEM_ALIAS_RENAME
Default: FALSE
If system alias renaming is allowed
TBD
_ASM_ALLOW_UNSAFE_RECONNECT
Default: TRUE
attempt unsafe reconnect to ASM
TBD
_ASM_ALLOWDEGENERATEMOUNTS
Default: FALSE
Allow force-mounts of DGs w/o proper quorum
TBD
_ASM_APPLIANCE_CONFIG_FILE
Default: NULL
Appliance configuration file name
TBD
_ASM_APPLIANCE_DISABLE_FG_CHECK
Default: FALSE
Disable failure group check
TBD
_ASM_APPLIANCE_IGNORE_OAK
Default: FALSE
Ignore OAK appliance library
 
_ASM_APPLIANCE_SLOT_FROM_PATH
Default: FALSE
Get appliance disk slot from disk path
 
_ASM_ASMB_MAX_WAIT_TIMEOUT
Default: 6
Timeout before processes are signaled with network interrupt
TBD
_ASM_ASMB_RCVTO
Default: 10
Receive timeout for ASMB in seconds
TBD
_ASM_ASYNC_SCRUB_REAP_WAIT
Default: 100000
Asyncronous scrubbing reaping IO wait in microseconds
TBD
_ASM_AUDIT_SP_PARAM
Default: <NULL>
ASM audit spare parameter
TBD
_ASM_AUSIZE
Default: 1048576
Allocation unit size
 
_ASM_AUTO_ONLINE_INTERVAL
Default: <NULL>
Auto online interval
TBD
_ASM_AUTOMATIC_REZONE
Default: TRUE
Automatically rebalance free space across zones
 
_ASM_AVOID_PST_SCANS
Default: TRUE
Avoid PST Scans
 
_ASM_BLKSIZE
Default: 4096
Metadata block size
 
_ASM_BR_LISTENER_PORT
Default: 51521
Bitrotter listener port for testing purpose
TBD
_ASM_BRFUZZ_IOS_LSNRPORT
Default: 0
IOS listener port for fuzzing with Bitrotter
TBD
_ASM_CANCEL_ALERT_TIME
Default: 600
Wait time for I/O cancel alert message (in seconds)
TBD
_ASM_CANCEL_DELTA
Default: 75000
Delta timeout for blocking big writes in milliseconds
TBD
_ASM_CCLINET_CLEANUP_TIMEOUT
Default: 300
Timeout before cleaning up remote cluster clients
TBD
_ASM_CHECK_FOR_MISBEHAVING_CF_CLIENTS
Default: FALSE
Check for misbehaving CF-holding clients
 
_ASM_COMPATIBILITY
Default: 11.2.0.2
Default ASM compatibility level
 
_ASM_DBA_BATCH
Default: 500000
ASM Disk Based Allocation Max Batch Size
 
_ASM_DBA_SPCCHK_THLD
Default: 100000
ASM Disk Based Allocation Space Check Threshold
 
_ASM_DBA_THRESHOLD
Default: 0
ASM Disk Based Allocation Threshold
 
_ASM_DBMSDG_NOHDRCHK
Default: FALSE
dbms_diskgroup.checkfile does not check block headers
 
_ASM_DEPENDENCY_UNDER_CFENQUEUE
Default: TRUE
Send dependency request if holding CF enqueue
TBD
_ASM_DIAG_DEAD_CLIENTS
Default: FALSE
Diagnostics for dead clients
 
_ASM_DIRECT_CON_EXPIRE_TIME
Default: 120
Expire time for idle direct connection to ASM instance
 
_ASM_DISABLE_AMDU_DUMP
Default: FALSE
Disable AMDU dump
 
_ASM_DISABLE_ASYNC_MSGS
Default: FALSE
Disable async intra-instance messaging
 
_ASM_DISABLE_DANGEROUS_FAILGROUP_CHECKING
Default: FALSE
Disable checking for dubious failgroup configurations
 
_ASM_DISABLE_FAILGROUP_COUNT_CHECKING
Default: FALSE
Disable checking for failure group count
TBD
_ASM_DISABLE_FAILGROUP_SIZE_CHECKING
Default: FALSE
Disable checking for failure group size
TBD
_ASM_DISABLE_MULTIPLE_INSTANCE_CHECK
Default: FALSE
Disable checking for multiple ASM instances on a given node
 
_ASM_DISABLE_PATCH_COMPAT
Default: FALSE
Disable DG patch compatibility checks
TBD
_ASM_DISABLE_PROACT_CLIENT_CLEANUP
Default: FALSE
Disable proactive client cleanup
TBD
_ASM_DISABLE_PROFILEDISCOVERY
Default: FALSE
Disable profile query for discovery
 
_ASM_DISABLE_REQUEST_TRACER
Default: TRUE
Disable kfioRqTracer
TBD
_ASM_DISABLE_SMR_CREATION
Default: FALSE
Do not create smr: Now if only I knew what "smr" was
 
_ASM_DISABLE_UFGMEMBERKILL
Default: FALSE
Disable ufg member kill
 
_ASM_DISABLE_UFG_DUMP
Default: FALSE
Disable terminated umbilicus diagnostic
 
_ASM_DISABLE_VTOC_CHECK
Default: TRUE
Disable vtoc/sector 0 check
TBD
_ASM_DISABLE_VXN_MAP_MESSAGES
Default: TRUE
Disable using vxn map messages
TBD
_ASM_DISK_REPAIR_TIME
Default: TRUE
Seconds to wait before dropping a failing disk
TBD
_ASM_DISKERR_TRACES
Default: 2
Number of read/write errors per disk a process can trace
 
_ASM_DISKGROUPS2
Default: None Defined
Disk groups to mount automatically set 2
TBD
_ASM_DISKGROUPS3
Default: None Defined
Disk groups to mount automatically set 3
TBD
_ASM_DISKGROUPS4
Default: None Defined
Disk groups to mount automatically set 4
TBD
_ASM_DISK_REPAIR_TIME
Default: 14400
Seconds to wait before dropping a failing disk
 
_ASM_EMULATE_NFS_DISK
Default: FALSE
Emulate NFS disk test event
 
_ASM_EMULMAX
Default: 10000
Max number of concurrent disks to emulate I /O errors
 
_ASM_EMULTIMEOUT
Default: 0
Timeout before emulation begins (in 3s ticks)
 
_ASM_ENABLE_BATCH_SCRUB
Default: FALSE

Allow scrubbing verification to run in batch mode

TBD
_ASM_ENABLE_KFIOS
Default: FALSE
Enable KFIOS module
TBD
_ASM_ENABLE_KFKS
Default: FALSE
Enable KFKS module
TBD
_ASM_ENABLE_LOSTWRITE_SCRUB
Default: FALSE
Allow lost write detection in scrubbing
TBD
_ASM_ENABLE_MULTIPLE_ASMB
Default: TRUE
Allow the ASM client to have multiple ASMB background processes
TBD
_ASM_ENABLE_PARITY_DATAFILE_CREATION
Default: FALSE
Enable parity datafiles creation
TBD
_ASM_ENABLE_PARITY_SCRUB
Default: FALSE
Allow scrubbing parity files
TBD
_ASM_ENABLE_PARITYFILE_CREATION
Default: TRUE
Enable parity files creation
TBD
_ASM_ENABLE_REPAIR_LOSTWRITE_SCRUB
Default: FALSE
Allow repairing lost write in scrubbing
TBD
_ASM_ENABLE_XROV
Default: FALSE
Enable XROV capability
 
_ASM_EVENREAD
Default: 2
ASM Even Read level
 
_ASM_EVENREAD_ALPHA
Default: 0
ASM Even Read Alpha
 
_ASM_EVENREAD_ALPHA2
Default: 0
ASM Even Read Second Alpha
 
_ASM_EVENREAD_FASTSTART
Default: 0
ASM Even Read Fast Start Threshold
 
_ASM_FAIL_RANDOM_RX
Default: FALSE
Randomly fail some RX enqueue gets
 
_ASM_FD_CLN_IDLE_SESS_TWAIT
Default: 60000000
Idle session time wait to run ASM FD cleanup
 
_ASM_FD_CLN_ON_FG
Default: FALSE
ASM stale FD cleanup on foregrounds
 
_ASM_FOB_TAC_FREQUENCY
Default: 9
Timeout frequency for FOB cleanup
 
_ASM_FORCE_PARITY_EXTENT_CHECK
Default: FALSE
Force parity extent integrity check
TBD
_ASM_FORCE_PARITYCHECK_REBALANCE
Default: FALSE
Force parity extent integrity check during rebalance
TBD
_ASM_FORCE_QUIESCE
Default: FALSE
Force diskgroup quiescing
 
_ASM_FORCE_VAM
Default: FALSE
Force VAM for external redundancy
 
_ASM_GLOBAL_DUMP_LEVEL
Default: 267
System state dump level for ASM asserts
 
_ASM_HBEATIOWAIT
Default: 120
Number of secs to wait for PST Async Hbeat IO return
 
_ASM_HBEATWAITQUANTUM
Default: 2
Quantum used to compute time-to-wait for a PST Hbeat check
 
_ASM_HEALTHCHECK_TIMEOUT
Default: 180
Seconds until health check takes action
 
_ASM_IMBALANCE_TOLERANCE
Default: 3
Hundredths of a percentage of inter-disk imbalance to tolerate
 
_ASM_INSTLOCK_QUOTA
Default: 0
ASM Instance Lock Quota
 
_ASM_IOSTAT_LATCH_COUNT
Default: 31
ASM I/O statistics latch count
 
_ASM_KFDPEVENT
Default: 0
KFDP event
 
_ASM_KILL_UNRESPONSIVE_CLIENTS
Default: TRUE
Kill unresponsive ASM clients
 
_ASM_LIBRARIES
Default: ufs
Library search order for discovery
 
_ASM_LOG_SCALE_REBALANCE
Default: FALSE
Rebalance power uses logarithmic scale
 
_ASM_LSOD_BUCKET_SIZE
Default: 67
ASM lsod bucket size
 
_ASM_MAXIO
Default: 1048576
Maximum size of individual I/O request
 
_ASM_MAX_COD_STRIDES
Default: 5
Maximum number of COD strides
 
_ASM_MAX_PARALLELIOS
Default: 256
Maximum simultaneous outstanding IOs
 
_ASM_MAX_REDO_BUFFER_SIZE
Default: 2097152
ASM maximum redo buffer size
 
_ASM_NETWORKS
Default: ASM
Network subnet addresses
 
_ASM_NETWORK_TIMEOUT
Default: 1
Keepalive timeout for ASM network connections
 
_ASM_NODEKILL_ESCALATE_TIME
Default: 180
Secs until escalating to nodekill if fence incomplete
 
_ASM_NOEVENREAD_DISKGROUPS
Default: None Defined
List of disk groups having even read disabled
 
_ASM_OFFLOAD_ALL
Default: FALSE
Offload all write operations to Exadata cells, when supported
 
_ASM_PARTNER_TARGET_DISK_PART
Default: 8
Target maximum number of disk partners for repartnering
 
_ASM_PARTNER_TARGET_FG_REL
Default: 4
Target maximum number of failure group relationships for repartnering
 
_ASM_PRIMARY_LOAD
Default: 1
Number of cycles/extents to load for non-mirrored files
 
_ASM_PRIMARY_LOAD_CYCLES
Default: TRUE
True if primary load is in cycles, false if extent counts
 
_ASM_PROCS_TRACE_DISKERR
Default: 5
Number of processes allowed to trace a disk failure
 
_ASM_PROXY_STARTWAIT
Default: 60
Maximum time to wait for ASM proxy connection
 
_ASM_RANDOM_ZONE
Default: FALSE
Random zones for new files
 
_ASM_READ_CANCEL
Default: AUTO
Read cancel timeout in milliseconds
 
_ASM_READ_CANCEL_BACK_OUT
Default: 5000
Time period in milliseconds when no reads are issued to a disk after a read is cancelled
 
_ASM_REBALANCE_PLAN_SIZE
Default: 120
Maximum rebalance work unit
 
_ASM_REBALANCE_SPACE_ERRORS
Default: 4
Number of out of space errors allowed before aborting rebalance
 
_ASM_RELOCATION_IGNORE_HARD_FAILURE
Default: 0
Ignore HARD for relocation
 
_ASM_RELOCATION_TRACE
Default: FALSE
Enable extent relocation tracing
 
_ASM_REMOTE_CLIENT_TIMEOUT
Default: 300
Timeout before killing disconnected remote clients
 
_ASM_REPAIRQUANTUM
Default: 60
Quantum (in 3s) used to compute elapsed time for disk drop
 
_ASM_RESERVE_SLAVES
Default: TRUE
Reserve ASM slaves for CF txns
 
_ASM_RESYNCCKPT
Default: 1024
Number of extents to resync before flushing checkpoint
 
_ASM_ROOT_DIRECTORY
Default: ASM
ASM default root directory
 
_ASM_RUNTIME_CAPABILITY_VOLUME_SUPPORT
Default: FALSE
Runtime capability for volume support returns supported
 
_ASM_SCRUB_LIMIT
Default: AUTO
ASM disk scrubbing power
 
_ASM_SCRUB_UNMATCHED_DBA
Default: 3
Scrub maximum number of blocks with unmatched DBA
 
_ASM_SECONDARY_LOAD
Default: 10000
Number of cycles/extents to load for mirrored files
 
_ASM_SECONDARY_LOAD_CYCLES
Default: FALSE
True if secondary load is in cycles, false if extent counts
 
_ASM_SERIALIZE_VOLUME_REBALANCE
Default: FALSE
Serialize volume rebalance
 
_ASM_SHADOW_CYCLE
Default: 3
Inverse shadow cycle requirement
 
_ASM_SKIP_DBFILE_IOS
Default: FALSE
Skip I/Os to database files (do only ASM metadata I/O)
 
_ASM_SKIP_DISKVAL_CHECK
Default: FALSE
Skip client side discovery for disk revalidate
 
_ASM_SKIP_RENAME_CHECK
Default: FALSE
Skip the checking of the clients for s/w compatibility for rename
 
_ASM_SKIP_RESIZE_CHECK
Default: FALSE
Skip the checking of the clients for s/w compatibility for resize
 
_ASM_STORAGEMAYSPLIT
Default: FALSE
PST Split Possible
 
_ASM_STRIPESIZE
Default: 131072
ASM file stripe size
 
_ASM_STRIPEWIDTH
Default: 8
ASM file stripe width
 
_ASM_SYNC_REBALANCE
Default: FALSE
Rebalance uses sync I/O
 
_ASM_TRACE_LIMIT_TIMEOUT
Default: 30000
Time-out in milliseconds to reset the number of traces per disk and the number of processes allowed to trace
 
_ASM_USD_BATCH
Default: 64
ASM USD Update Max Batch Size
 
_ASM_WAIT_TIME
Default: 18
Max/imum time to wait before asmb exits
 
_ASM_WRITE_CANCEL
Default: AUTO
Write timeout in milliseconds
 
_ASM_XROV_NSTATS
Default: 0
Specify number of IOs before stats
 
_ASM_XROV_NVIOS
Default: 4
Specify number of VIO processes
 
_ASM_XROV_RSNMOD
Default: 1
Specify reason mode
 
_ASM_XROV_SINGLE
Default: TRUE
Enable single issues of IOs
 
 
Automatic Workload Repository (AWR)
_AWR_CDBPERF_THRESHOLD
Default: 21
Setting for AWR CDBPERF Threshold
_awr_cdbperf_threshold=21
_AWR_CORRUPT_MODE
Default: FALSE
AWR Corrupt Mode
Range of values: {TRUE | FALSE}
_awr_corrupt_mode=TRUE
_AWR_DISABLED_FLUSH_TABLES Disable flushing of specified AWR tables
TBD
_AWR_DISABLED_PURGE_TABLES Disable purging of specified AWR tables
TBD
_AWR_FLUSH_THRESHOLD_METRICS
Default TRUE
Enable/Disable Flushing AWR Threshold Metrics
Range of values: {TRUE | FALSE}
_awr_flush_threshold_metrics=TRUE
_AWR_FLUSH_WORKLOAD_METRICS
Default: FALSE
Enable/Disable Flushing AWR Workload Metrics
Range of values: {TRUE | FALSE}
_awr_flush_workload_metrics=TRUE
_AWR_MMON_CPUUSAGE
Default: TRUE
Enable/disable AWR MMON CPU Usage Tracking
Range of values: {TRUE | FALSE}
_awr_mmn_cpuusage=TRUE
_AWR_MMON_DEEP_PURGE_ALL_EXPIRED
Default: FALSE
Allows deep purge to purge AWR data for all expired snapshots
Range of values: {TRUE | FALSE}
_awr_mmon_deep_purge_all_expired=TRUE
_AWR_MMON_DEEP_PURGE_EXTENT
Default: 7
Set extent of rows to check each deep purge run
_awrmmon_deep_purge_extent=7
_AWR_MMON_DEEP_PURGE_INTERVAL
Default: 7
Set interval for deep purge of AWR contents
_awr_mmon_deep_purge_interval=7
_AWR_MMON_DEEP_PURGE_NUMROWS
Default: 5000
Set max number of rows per table to delete each deep purge run
_awr_mmon_deep_purge_numrows=5000
_AWR_PARTITION_INTERVAL
Default: 0
Setting for AWR Partition Interval
_awr_partition_interval=0
_AWR_PDB_REGISTRATION_ENABLED
Default: FALSE
Parameter to enable/disable AWR PDB Registration
Range of values: {TRUE | FALSE}
_awr_pdb_registration_enabled=TRUE
_AWR_RESTRICT_MODE
Default: FALSE
AWR Restrict Mode
Range of values: {TRUE | FALSE}
_awr_restrict_mode=TRUE
_AWR_SNAPSHOT_LEVEL
Default: BESTFIT
Set Default AWR snapshot level
_awr_snapshot_level=BESTFIT
_AWR_SQL_CHILD_LIMIT
Default: 200
Setting for AWR SQL Child Limit
_awr_sql_child_limit=100
_FLUSH_PLAN_IN_AWR_SQL
Default: 0
Plan is being flushed from an AWR flush SQL
_flush_plan_in_awr_sql=0
_REMOTE_AWR_ENABLED
Default: FALSE
Enable/disable Remote AWR Mode
_remote_awr_enabled=TRUE
_AWR_CDBPERF_THRESHOLD
Default: 21
Setting for AWR CDBPERF Threshold
 
_AWR_CORRUPT_MODE
Default: FALSE
AWR Corrupt Mode
 
_AWR_DISABLED_FLUSH_TABLES
Default: None
Disable flushing of specified AWR tables
TBD
_AWR_DISABLED_PURGE_TABLES
Default: None Defined
Disable purging of specified AWR tables
 
_AWR_FLUSH_THRESHOLD_METRICS
Default: TRUE
Enable/Disable Flushing AWR Threshold Metrics
 
_AWR_FLUSH_WORKLOAD_METRICS
Default: FALSE
Enable/Disable Flushing AWR Workload Metrics
 
_AWR_MMON_CPUUSAGE
Default: TRUE
Enable/disable AWR MMON CPU Usage Tracking
 
_AWR_MMON_DEEP_PURGE_ALL_EXPIRED
Default: FALSE
Allows deep purge to purge AWR data for all expired snapshots
 
_AWR_MMON_DEEP_PURGE_EXTENT
Default: 7
Set extent of rows to check each deep purge run
 
_AWR_MMON_DEEP_PURGE_INTERVAL
Default: 7
Set interval for deep purge of AWR contents
 
_AWR_MMON_DEEP_PURGE_NUMROWS
Default: 5000
Set max number of rows per table to delete each deep purge run
 
_AWR_PARTITION_INTERVAL
Default: 0
Setting for AWR Partition Interval
 
_AWR_PDB_REGISTRATION_ENABLED
Default: FALSE
Parameter to enable/disable AWR PDB Registration
 
_AWR_REMOTE_TARGET_DBLINK
Default: AWR
Remote Target DBLink for Flushing
 
_AWR_RESTRICT_MODE
Default: FALSE
By default the value is FALSE which indicates that AWR snapshots will not be made when the database is in restricted mode.
See the DBMS_WORKLOAD_REPOSITORY.CONTROL_RESTRICTED_SNAPSHOT Demo using the link at page bottom
_AWR_SNAPSHOT_LEVEL
Default: 'BESTFIT'
Set Default AWR snapshot level
 
_AWR_SQL_CHILD_LIMIT
Default: 200
Setting for AWR SQL Child Limit
 
_FLUSH_PLAN_IN_AWR_SQL
Default: 0
Plan is being flushed from an AWR flush SQL
 
 
Backup and Restore
_BACKUP_ALIGN_WRITE_IO

Default: TRUE
Align backup write I/Os
_backup_align_write_io=FALSE
_BACKUP_APPLIANCE_ENABLED

Default: FALSE
Backup Appliance Enabled
_backup_appliance_enabled=TRUE
_BACKUP_AUTOMATIC_RETRY

Default: 10
Automatic retry on backup write errors
TBD
_BACKUP_BLOCK0

Default: default
Backup block0
TBD
_BACKUP_BOOL_SPARE1
Default: FALSE
Backup bool spare1
TBD
_BACKUP_BOOL_SPARE2
Default: FALSE
Backup bool spare2
TBD
_BACKUP_BOOL_SPARE3
Default: FALSE
Backup bool spare3
TBD
_BACKUP_BOOL_SPARE4
Default: FALSE
Backup bool spare4
TBD
_BACKUP_COMPRESS

Default: FALSE
Always enable backup compression
_backup_compress=TRUE
_BACKUP_DISK_BUFCNT
Default: 0
Number of buffers used for DISK channels
TBD
_BACKUP_DISK_BUFSZ
Default: 0
Size of buffers used for DISK channels
TBD
_BACKUP_DISK_IO_SLAVES
Default: 0
Backup Disk I/O slaves
TBD
_BACKUP_DYNAMIC_BUFFERS
Default: TRUE
Dynamically compute backup/restore buffer sizes
TBD
_BACKUP_ENCRYPT_OPT_MODE
Default: 4294967294
Specifies encryption block optimization mode
TBD
_BACKUP_FILE_BUFCNT
Default: 0
Number of buffers used for file access
TBD
_BACKUP_FILE_BUFSZ
Default: 0
Size of buffers used for file access
TBD
_BACKUP_INT_SPARE1
Default: 4294967294
Backup int spare1
TBD
_BACKUP_INT_SPARE2
Default: 4294967294
Backup int spare2
TBD
_BACKUP_INT_SPARE3
Default: 4294967294
Backup int spare3
TBD
_BACKUP_INT_SPARE4
Default: 4294967294
Backup int spare4
TBD
_BACKUP_IO_POOL_SIZE
Default: 1048576
Memory to reserve from the large pool
_backup_io_pool_size=2097152
_BACKUP_KGC_BZ2_BUFSZ
Default: 0
Specifies buffer size to be used by BZ2 compression
_backup_kgc_bz2_bufsz=0
_BACKUP_KGC_BZ2_NITERS
Default: 0
Specifies number of iterations done by BZ2 compression
_backup_kgc_bz2_niters=0
_BACKUP_KGC_BZ2_TYPE
Default: 0
Specifies type used by BZ2 compression
_backup_kgc_bz2_type=0
_BACKUP_KGC_BZIP2_BLKSZ
Default: 9
Specifies buffer size to be used by BZIP2 compression
_backup_kgc_bz2_=9
_BACKUP_KGC_LZO_BUFSZ
Default: 262144
Specifies buffer size to be used by LZO compression
_backup_kgc_bz2_=262144
_BACKUP_KGC_MEDIUM_SCHEME
Default: DEFAULT
Specifies medium compression scheme
TBD
_BACKUP_KGC_SCHEME
Default: ZLIB
Specifies compression scheme
TBD
_BACKUP_KGC_ZLIB_COMPLEVEL
Default: 1
Specifies compression (performance) level for ZLIB compression
TBD
_BACKUP_KGC_ZLIB_MEMLEVEL
Default: 8
Specifies memory level for ZLIB compression
TBD
_BACKUP_KGC_ZLIB_WINDOWBITS
Default: 15
Specifies window size for ZLIB compression
TBD
_BACKUP_KGC_ZSTD_BUFSZ
Default: 262144
Secifies buffer size to be used by ZSTD compression
TBD
_BACKUP_KGC_ZSTD_COMPLEVEL
Default: 3
Specifies compression (performance) level for ZSTD compression
TBD
_BACKUP_KSFQ_BUFCNT
Default: 0
Number of buffers used for backup/restore
TBD
_BACKUP_KSFQ_BUFMEM_MAX
Default: 268435456
Maximum amount of memory (in bytes) used for buffers for backup/restore
TBD
_BACKUP_KSFQ_BUFSZ
Default: 0
Size of buffers used for backup/restore
TBD
_BACKUP_MAX_GAP_SIZE
Default: 4294967294
Largest gap in an incremental/optimized backup buffer, in bytes
TBD
_BACKUP_MAX_WALLET_SESSION

Default: 50
Specifies maximum wallet session for backup
_backup_max_wallet_session_=60
_BACKUP_MIN_CT_UNUSED_OPTIM
Default: 2097152
Minimum size in bytes of change tracking to apply unused space optimization
TBD
_BACKUP_SEQ_BUFCNT
Default: 0
Number of buffers used for non-DISK channels
TBD
_BACKUP_SEQ_BUFSZ
Default: 0
Size of buffers used for non-DISK channels
TBD
_BACKUP_TEXT_SPARE1
Default: None Defined
Backup text spare1
TBD
_BACKUP_TEXT_SPARE2
Default: None Defined
Backup text spare2
TBD
_BACKUP_TEXT_SPARE3
Default: None Defined
Backup text spare3
TBD
_BACKUP_TEXT_SPARE4
Default: None Defined
Backup text spare4
TBD
 
Block Change Tracking
_BCT_BITMAPS_PER_FILE
Default: 8
Number of bitmaps to store for each datafile
_bct_bitmaps_per_file=12
_BCT_BUFFER_ALLOCATION_MAX
Default: 104857600
maximum size of all change tracking buffer allocations, in bytes
TBD
_BCT_BUFFER_ALLOCATION_MIN_EXTENTS
Default: 1
mininum number of extents to allocate per buffer alloca
_bct_buffer_allocation_min_extents=2
_BCT_BUFFER_ALLOCATION_SIZE
Default: 2097152
size of one change tracking buffer allocation, in bytes
TBD
_BCT_CHUNK_SIZE
Default: 0
change tracking datafile chunk size, in bytes
TBD
_BCT_CRASH_RESERVE_SIZE
Default: 262144
change tracking reserved crash recovery SGA space, in bytes
_bct_crash_reserve_size=393216
_BCT_FILE_BLOCK_SIZE
Default: 0
block size of change tracking file, in bytes
_bct_file_block_size=8192
_BCT_FILE_EXTENT_SIZE
Default: 0
extent size of change tracking file, in bytes
_bct_file_extent_size=65536
_BCT_FIXTAB_FILE
Default: NULL
change tracking file for fixed tables
_bct_fixtab_file='/u01/oradata/flash_recovery_area/bct/bctfile.bct';
_BCT_HEALTH_CHECK_INTERVAL
Default: 60
CTWR health check interval (seconds), zero to disable
_bct_health_check_interval=0
_BCT_INITIAL_PRIVATE_DBA_BUFFER_SIZE
Default: 0
initial number of entries in the private change tracking dba buffers
_bct_initial_private_dba_buffer_size=8192
_BCT_MRP_TIMEOUT
Default: 600
CTWR MRP wait timeout (seconds), zero to wait forever
_bct_mrp_timeout=900
_BCT_PUBLIC_DBA_BUFFER_DYNRESIZE
Default: 2
Allow dynamic resizing of public dba buffers, zero to disable
_bct_public_dba_buffer_dynresize=2
_BCT_PUBLIC_DBA_BUFFER_MAXSIZE
Default: 0
Max buffer size permitted for public dba buffers, in bytes
_bct_public_dba_buffer_maxsize=0
_BCT_PUBLIC_DBA_BUFFER_SIZE
Default: 0
total size of all public change tracking dba buffers, in bytes
_bct_public_dba_buffer_size=104857600
 
Compression
_ADVANCED_INDEX_COMPRESSION_CMP_OPTIONS
Default: 0
Advanced index compression cmp options
_advanced_index_compression_cmp_options=1
_ADVANCED_INDEX_COMPRESSION_OPT_OPTIONS
Default: 0
Advanced index compression opt options
_advanced_index_compression_opt_options=1
_ADVANCED_INDEX_COMPRESSION_OPTIONS
Default: 0
Advanced index compression options
_advanced_index_compression_options=11
_ADVANCED_INDEX_COMPRESSION_OPTIONS_VALUE
Default: 0
Advanced index compression options2
_advanced_index_compression_options_value=1
_ADVANCED_INDEX_COMPRESSION_RECMP_CRSZ
Default: 10
Advanced index compression limit recomp cr
_advanced_index_compression_recmp_crsz=12
_ADVANCED_INDEX_COMPRESSION_RECMP_CUSZ
Default: 90
Advanced index compression limit recomp cu
_advanced_index_compression_recmp_cusz=100
_ADVANCED_INDEX_COMPRESSION_RECMP_NPRG
Default: 10
Advanced index compression limit recomp pu
_advanced_index_compression_recmp_nprg=12
_ADVANCED_INDEX_COMPRESSION_TRACE
Default: 0
Advanced index compression trace
_advanced_index_compression_trace=1
_ADVANCED_INDEX_COMPRESSION_TST_OPTIONS
Default: 0
advanced index compression test options
_advanced_index_compression_tst_options=1
_ADVANCED_INDEX_COMPRESSION_UMEM_OPTIONS 
Default: 2147483647
Advanced index compression umem options
_advanced_index_compression_umem_options=1431655765
 

Related Topics
DBMS_WORKLOAD_REPOSITORY
Init.ora & SPFILE
Synonyms
Underscore Parameters: Page 2 of 5
Underscore Parameters: Page 3 of 5
Underscore Parameters: Page 4 of 5
Underscore Parameters: Page 5 of 5
What's New In 19c
What's New In 20c-21c