Oracle | Undocumented Initialization Parameters

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