Oracle Undocumented Underscore Startup Parameters
Version 21c
Page 3 of 5

General Information
Library Note Morgan's Library Page Header
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working note 5397 underscore parms
22 pages of 17 = 374 per page
14-15 pages ... not easily doable
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 3 of 5 and has been posted to the Library. Additional pages and sections will be published as they are completed.

For a list of deprecated and removed parameters view $ORACLE_HOME/rdbms/admin/parameters.properties;
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
Active Session History Data Guard KCFIS
Adaptive Queries Data Pump Memory
ADDM DB Block Network & Connectivity
Advanced Queuing DB Cache NLS Parameters
Archive Logging Diagnostics Optimizer
Audit Distributed Replication PL/SQL
Automatic Storage Management Exadata RAC
Automatic Workload Repository File Locations Result Cache
Backup & Restore Flashback Security
Block Change Tracking Group By Tracing
Bloom Filters Hang Manager Transactions
Buffers In-Memory Undo
Compression Instance Identification Miscellaneous
Container_Database I/O (slaves/read%count) Undocumented
 
IN MEMORY
__INMEMORY_EXT_ROAREA
Default: 0		 Actual size in bytes of inmemory ro extension area
TBD
__INMEMORY_EXT_RWAAREA
Default: 0		 Actual size in bytes of inmemory rw extension area
TBD
_DM_INMEMORY_THRESHOLD
Default: 1000000		 In-memory cardinality threshold
TBD
_IN_MEMORY_CDT
Default: LIMITED		 In Memory CDT
TBD
_IN_MEMORY_CDT_MAXPX
Default: 4		 Parallelizers allowed for IMCDT
TBD
_IN_MEMORY_CLEANUP_WAIT_TIMEOUT
Default: 10000		 Timemout for IMCDT cleanup waiting for end of scan
TBD
_IN_MEMORY_MEMORY_THRESHOLD
Default: 40		 In Memory CDT memory threshold
TBD
_IN_MEMORY_TBS_SEARCH
Default: TRUE		 FALSE menas disable fast path for alter tablespace read only
TBD
_IN_MEMORY_TS_ONLY
Default: OFF		 In Memory CDT use temp segment only
TBD
_IN_MEMORY_UNDO
Default: TRUE		 Make in memory undo for top level transactions
TBD
_INMEMORY_64K_PERCENT
Default: 30		 Percentage of in-memory area for 64k pools
TBD
_INMEMORY_ADG_BATCHED_FLUSH
Default: TRUE		 If true, batched flush is performed
TBD
_INMEMORY_ADG_JOURNAL_QUOTA
Default: FALSE		 If true, throttled mining is performed under space pressure
TBD
_INMEMORY_ADG_PARALLEL_FLUSH
Default: TRUE		 If true, parallel flush is performed
TBD
_INMEMORY_ADG_PERIODIC_SORT
Default: FALSE		 If true, periodic sort is performed
TBD
_INMEMORY_ADG_QUIESCE_TIMEOUT
Default: 2		 Timeout for getting ZQ enque
TBD
_INMEMORY_ANALYZER_OPTIMIE_FOR
Default: 0		 Inmemory analyzer optimize for
TBD
_INMEMORY_AUTO_DISTRIBUTE
Default: TRUE		 If true, enableauto distribute
TBD
_INMEMORY_AUTODIST_2SAFE
Default: FALSE		 If true, enable auto distribute with 2safe
TBD
_INMEMORY_BUFFER_WAITTIME
Default: 100		 Wait interval for one SMU or IMCU to be freed
TBD
_INMEMORY_CHECK_PROT_META
Default: FALSE		 If true, marks SMU area read only to prevent stray writes
TBD
_INMEMORY_CHECKSUM
Default: FALSE		 If true, checksums in-memory area to detect stray writes
TBD
_INMEMORY_CRCLONE_BUFFER_SIZE
Default: 131072		 In-memory CR Clone buffer size
TBD
_INMEMORY_CRCLONE_MIN_CLONES
Default: 6		 In-memory CR Clone minimum number of clones
TBD
_INMEMORY_CRCLONE_MIN_SPACE _PERCENT
Default: 50		 In-memory CR Clone minimum space percentage
TBD
_INMEMORY_CRCLONE_THRESHOLD _ROWS
Default: 100		 In-memory CR Clone threshold rows
TBD
_INMEMORY_CU_CHECKSUM
Default: FALASE		 If true, checksums CU to detect stray writes
TBD
_INMEMORY_CUDROP_TIMEOUT
Default: 1000		 Maximum wait time for IMCU to be freed during drop
TBD
_INMEMORY_DBG_SCAN
Default: 0		 In-memory scan debugging
TBD
_INMEMORY_DEFAULT_FLAGS
Default: 8459		 Default flags based on inmemory_clause_default
TBD
_INMEMORY_DEFAULT_NEW
Default: FALSE		 Force in-memory on new tables
TBD
_INMEMORY_DEFAULT_SVC
Default: 0		 Default In-Memory distribute service type for new tables
TBD
_INMEMORY_DEFAULT_SVCNAME
Default: <No Value>		 Default In-Memory distribute service name for new tables
TBD
_INMEMORY_DELTA_POPULATION
Default: 0		 Control Delta IMCU population
TBD
_INMEMORY_DIRECT_READS
Default: 1		 Direct-reads for SMUs population repopulation
TBD
_INMEMORY_DISABLE_ALTER_IMCO _CYCLE
Default: FALSE		 In-memory disable alter imco cycle
TBD
_INMEMORY_DISABLE_SELECTIVE _VIRCOLS
Default: FALSE		 Disable selective columns for VCs/IMEs
TBD
_INMEMORY_DISTRIBUTE_ONEDEMAND _TIMEOUT
Default: 300		 On demand timeout for redistribute
TBD
_INMEMORY_DISTRIBUTE_TIMEOUT
Default: 300		 If true, enable auto distribute with 2safe
TBD
_INMEMORY_DRCANCEL_CU_PERCENT
Default: 80		 IMCU percentage threshold to switch from DR to BC
TBD
_INMEMORY_DYNAMIC_SCAN_DSABLE_THRESHOLD
Default: 10		 Inmemory dynamic scan disable threshold
TBD
_INMEMORY_DYNAMIC_SCNAS
Default: AUTO		 Enable IM Dynamic Scans
TBD
_INMEMORY_DYNAMIC_SCANS_ANALYZE _BATCH_SIZE
Default: 5		 Inmemory dynamic scan analyze batch size
TBD
_INMEMORY_DYNAMIC_SCANS_BATCH _SIZE
Default: 500		 Number of steady state outstanding tasks
TBD
_INMEMORY_DYNAMIC_SCANS_DBG
Default: 0		 Inmemory dynamic scans debug
TBD
_INMEMORY_ENABLE_READONLY
Default: TRUE		 Enable Inmemory on read only DB instance
TBD
_INMEMORY_ENABLE_STAT_ALERT
Default: 500		 Dump in-memory stats in alert log file
TBD
_INMEMORY_ENABLE_SYS
Default: FALSE		 Enable in-memory on system tablespace with sys user
TBD
_INMEMORY_EXCLTO_TIMEOUT
Default: 100		 Maximum wait time to pin SMU for cleanout
TBD
_INMEMORY_EXPRESSION_COUNT
Default: 20		 IME number of expressions to lookup from the ESS
TBD
_INMEMORY_EXPRESSIONS_AREA _PERCENT
Default: 10		 Percentage of in-memory area for IMEUs
TBD
_INMEMORY_EXPRESSONS_MARK _UNUSED
Default: FALSE		 Mark cold IME expressions unused instead of no inmemory
TBD
_INMEMORY_EXT_ROAREA
Default: 0		 Size in bytes of inmemory rw extension area
TBD
_INMEMORY_EXT_RWAREA
Default: 0		 Size in bytes of inmemory rw extension area
TBD
_INMEMORY_EXTERNAL_TABLE
Default: TRUE		 Enable inmemory external table
TBD
_INMEMORY_FASTSTART_CONTROL _FLAGS
Default: 0		 In-memory faststart control flags
TBD
_INMEMORY_FORCE_FS
Default: FALSE		 In-memory faststart force
TBD
_INMEMORY_FORCE_FS_TBS
Default: SYSAUX		 In-memory faststart force tablespace
TBD
_INMEMORY_FORCE_FS_TBS_SIZE
Default: 1073741824		 In-memory faststart force tablespace size
TBD
_INMEMORY_FORCE_NON_ENGINEERED
Default: FALSE		 Force non-engineered systems in-memory behavior on RAC
TBD
_INMEMORY_FORMAT_COMPATIBLE
Default: 19.0.0		 In-memory format compatibility parameter
TBD
_INMEMORY_FS_BLK_INV_BLK_PERCENT
Default: 50		 In-memory faststart CU invalidation threshold(blocks)
TBD
_INMEMORY_FS_BLK_INV_BLKCNT
Default:<No Value> 		In-memory faststart CU invalidation threshold(blocks)
TBD
_INMEMORY_FS_DMLVERIFY_READ _AHEAD_CNT
Default: 10		 In-memory faststart dmlverify read ahead count
TBD
_INMEMORY_FS_ENABLE
Default: TRUE		 In-memory faststart enable
TBD
_INMEMORY_FS_ENABLE_BLK_LVL_INV
Default: TRUE		 In-memory faststart enable block level invalidation
TBD
_INMEMORY_FS_NODML
Default: FALSE		 In-memory faststart assumes no dmls while populating
TBD
_INMEMORY_FS_PRUNE_PCT
Default: 10		 In-memory faststart out of memORY prune percent
TBD
_INMEMORY_FS_RAISE_ERROR
Default: FALSE		 In-memory faststart raise error
TBD
_INMEMORY_FS_TBSMAXSZ
Default: <No Value> 		In-memory faststart tablespace maximum size
TBD
_INMEMORY_FS_VERIFY
Default: FALSE		 In-memory faststart verify
TBD
_INMEMORY_FSDW_CNT
Default: 2147483647		 In-memory faststart defer writes per cycle
TBD
_INMEMORY_FSDW_ENABLE
Default: TRUE		 In-memory faststart deferwrite enable
TBD
_INMEMORY_FSDW_INLINE
Default: FALSE		 In-memory faststart deferwrite inline
TBD
_INMEMORY_FSDW_MAXCNT
Default: 10		 In-memory faststart max defer writes per cycle
TBD
_INMEMORY_FSDW_MAXMEM
Default: 104755200		 In-memory faststart max defer writes memory cap
TBD
_INMEMORY_FSDW_ON_POPULATE
Default: TRUE		 In-memory faststart deferwrite on populate
TBD
_INMEMORY_FSDW_PENALTY _THRESHOLD
Default: 20		 In-memory faststart deferwrite penalty threshold
TBD
_INMEMORY_FSDW_POPULATE_THRESHOLD _MULTIPLIER
Default: 10		 In-memory faststart deferwrite populate threshold multiplier
TBD
_INMEMORY_FSDW_PRIORITY_PENALTY_PERCENT
Default: 10		 In-memory faststart defer write percent priority for penalized
TBD
_INMEMORY_FSDW_PRIORITY _POPULATION_PERCENTON
Default: 100		 In-memory faststart defer write percent priority for population
TBD
_INMEMORY_FSDW_PRIORITY _REPOPULATION_PERCENT
Default: 90		 In-memory faststart defer write percent priority for repopulation
TBD
_INMEMORY_FSDW_SCHEDLRTM
Default: 1		 In-memory faststart defer write scheduler cycle (sec)
TBD
_INMEMORY_FSDW_SCHEDULER_DEDICATED
Default: FALSE		 In-memory faststart defer write dedicated scheduler
TBD
_INMEMORY_FSDW_TASK_TIMEOUT
Default: 20		 In-memory faststart defer writes task timeout (sec)
TBD
_INMEMORY_FSDW_THRESHOLD
Default: 300		 In-memory faststart defer write minimum interval (millisec)
TBD
_INMEMORY_GRANULE_SIZE
Default: 134217728		 In-memory granule size
TBD
_INMEMORY_GRPCOLINV_BUFFER_SIZE
Default: 131072		 In-memory grpcolinv buffer size
TBD
_INMEMORY_GRPCOLINV_GRANULARITY
Default: 1		 In-memory grpcolinv blks per colmap
TBD
_INMEMORY_HWM_EXPAND_PERCENT
Default: 20		 Max blks percent can exceed in hwmimcu
TBD
_INMEMORY_HWM_EXPANSION
Default: 0		 If 0, the highwatermark CU is dropped when expanded
TBD
_INMEMORY_IMCO_CYCLE
Default: 120		 IMCO cycle in seconds (sleep period)
TBD
_INMEMORY_IMCU_ALIGN
Default: TRUE		 Enforce 8M IMCU alignment
TBD
_INMEMORY_IMCU_POPULATE_MINBYTES
Default: 5242880		 Minimum free space in IMA for populating IMCU
TBD
_INMEMORY_IMCU_SOURCE_ANALYZE _BYTES
Default: 134217728		 Number of source analyze bytes per IMCU
TBD
_INMEMORY_IMCU_SOURCE_BLOCKS
Default: 0		 Number of source blocks per IMCU
TBD
_INMEMORY_IMCU_SOURCE_EXTENTS
Default: 0		 Number of source extents per IMCU
TBD
_INMEMORY_IMCU_SOURCE_MAXBYTES
Default: 536870912		 IMCU maximum source size in bytes
TBD
_INMEMORY_IMCU_SOURCE_MINBYTES
Default: 1048576		 Number of minimum source bytes per IMCU
TBD
_INMEMORY_IMCU_TARGET_BYTES
Default: 0		 IMCU target size in bytes
TBD
_INMEMORY_IMCU_TARGET_MAXROWS
Default: 8388608		 IMCU maximum target number of rows
TBD
_INMEMORY_IMCU_TARGET_ROWS
Default: 0		 IMCU target number of rows
TBD
_INMEMORY_IME_INCREPOP _THRESHOLD
Default: 1		 Invalidation threshold for IME incremental repopulation
TBD
_INMEMORY_INCREMENTAL _REPOPULATION
Default: TRUE		 If true, incremental repopulation of IMCU will be attempted
TBD
_INMEMORY_INVALIDATE_CURSORS
Default: TRUE		 In-memory populate enable cursor invalidations
TBD
_INMEMORY_JOURNAL_CHECK
Default: 0		 Depending on value does one of the DML verifications
TBD
_INMEMORY_JOURNAL_CLA_STRIDE
Default: 4		 Inmemory journal format cla stride
TBD
_INMEMORY_JOURNAL_FORMAT
Default: 1		 Inmemory journal format options
TBD
_INMEMORY_JOURNAL_ROW_LOGGING
Default: FALSE		 If true, log the entire row into the in-memory journal
TBD
_INMEMORY_JOURNAL_SCAN
Default: 0		 Inmemory journal scan enable
TBD
_INMEMORY_JOURNAL_SCAN_FORMAT
Default: TRUE		 If true, the set journal format will be used for scan
TBD
_INMEMORY_LOCK_FOR_SMUCREATE
Default: FALSE		 Take object lock during smu creation
TBD
_INMEMORY_LOG_LEVEL
Default: 0		 In-memory log level
TBD
_INMEMORY_MAX_DELTA
Default: 5		 Inmemory max number of deltas per CU
TBD
_INMEMORY_MAX_EXPRESSION_TABLE
Default: 50		 IME maximum number of SYS_IME VCs in a table
TBD
_INMEMORY_MAX_POPULATE_RETRY
Default: 3		 IM populate maximum number of retry
TBD
_INMEMORY_MAX_QUEUED_TASKS
Default: 0		 Maximum queued populating tasks on the auxiliary queue
TBD
_INMEMORY_MEMPROT
Default: TRUE		 Enable or disable memory protection for in-memory
TBD
_INMEMORY_MIN_DELTA_BLOCKS
Default: 50		 Inmemory minimum blocks per delta
TBD
_INMEMORY_MIN_DELTA_ROWS
Default: 255		 Inmemory minimum rows per delta
TBD
_INMEMORY_MIN_IMA_DEFERSIZE
Default: 0		 Defer in-memory area allocation beyond this size
TBD
_INMEMORY_NUM_HASH_LATCHES
Default: 256		 Maximum number of latches for IM buffers
TBD
_INMEMORY_PARALLEL_LOAD_EXT
Default: TRUE		 Parallel load inmemory extern table
TBD
_INMEMORY_PARTROWLOCK_THRESHOLD
Default: 10		 Number of committed rows that stay not cleaned out
TBD
_INMEMORY_PATCH_BACKGROUND_BLOCKS
Default: 200		 In-memory SMU patch threshold blocks to start background tasks
TBD
_INMEMORY_PATCH_THRESHOLD_BLOCKS
Default: 25		 In-memory SMU patch threshold blocks
TBD
_INMEMORY_PCT_INV_BLOCKS_INVALIDATE_IMCU
Default: 100		 In-memory percentage invalid blocks for IMCU invalidation
TBD
_INMEMORY_PCT_INV_ROWS_INVALIDATE_IMCU
Default: 50		 In-memory percentage invalid rows for IMCU invalidation
TBD
_INMEMORY_PGA_PER_SERVER
Default: 536870912		 Minimum pga needed per inmemory populate server
TBD
_INMEMORY_PIN_HIST_MODE
Default: 16		 Settings for IM pinned buffer history
TBD
_INMEMORY_POPULATE_FG
Default: FALSE		 Populate in foreground
TBD
_INMEMORY_POPULATE_WAIT
Default: FALSE		 Wait for population to complete
TBD
_INMEMORY_POPULATE_WAIT_MAX
Default: 600		 Maximum wait time in seconds for segment populate
TBD
_INMEMORY_PREFER_XMEM_MEMCOMPRESS
Default: <NULL>		 Prefer to store tables with given memcompress levels in xmem
TBD
_INMEMORY_PREFER_XMEM_PRIORITY
Default: <NULL>		 Prefer to store tables with given priority levels in xmem
TBD
_INMEMORY_PREFIX_ENCODE_DSBS
Default: FALSE		 Prefix-encode the DSB-dictionary
TBD
_INMEMORY_PREPOPULATE
Default: TRUE		 Enable inmemory populate by IMCO
TBD
_INMEMORY_PREPOPULATE_FG
Default: 0		 Force prepopulate of in-memory segment in foreground
TBD
_INMEMORY_PRIVATE_JORNAL_MAXEXTS
Default: 5000000		 Max number of extents per PJ
TBD
_INMEMORY_PRIVATE_JOURNAL_NUMBKTS
Default: 512		 Number of priv jrnl ht bkts
TBD
_INMEMORY_PRIVATE_JOURNAL_NUMGRAN
Default: 255		 Number of granules per HT node
TBD
_INMEMORY_PRIVATE_JOURNAL_QUOTA
Default: 100		 Quota for transaction in-memory private journals
TBD
_INMEMORY_PRIVATE_JOURNAL_SHAREDPOOL _QUOTA
Default: 20		 Quota for transaction in-memory objects
TBD
_INMEMORY_PRUNING
Default: ON		 _inmemory_pruning ON In-memory pruning
TBD
_INMEMORY_QUERY-CHECK
Default: 0		 In-memory query checking
TBD
_INMEMORY_QUERY_FETCH_BY_ROWID
Default: FALSE		 In-memory fetch-by-rowid enabled
TBD
_INMEMORY_QUERY_SCAN
Default: TRUE		 In-memory scan enabled
TBD
_INMEMORY_RELIMCUSZ_THRESH
Default: 25		 In-memory relative imcusz thresh for direct reads
TBD
_INMEMORY_REPOPULATE_DISABLE
Default: 2		 Disable In-memory repopulate
TBD
_INMEMORY_REPOPULATE_FLAGS
Default: 2		 In-memory repopulate decision flags
TBD
_INMEMORY_REPOPULATE_INVALIDATE_RATE _PERCENT
Default: 0		 In-memory repopulate invalidate rate percent
TBD
_INMEMORY_REPOPULATE_OPTIMIZE
Default: TRUE		 If true, itl transfer will be attempted during repopulation of IMCU
TBD
_INMEMORY_REPOPULATE_PRIORITY_SCALE _FACTOR
Default: 100		 In-memory repopulate priority threshold scale factor
TBD
_INMEMORY_REPOPULATE_PRIORITY_THRESHOLD _BLOCK
Default: 320		 In-memory repopulate priority threshold block
TBD
_INMEMORY_REPOPULATE_PRIORITY_THRESHOLD _ROW
Default: 160		 In-memory repopulate priority threshold row
TBD
_INMEMORY_REPOPULATE_THRESHOLD_BLOCKS
Default: <NULL>		 In-memory repopulate threshold number of modified blocks
TBD
_INMEMORY_REPOPULATE_THRESHOLD_BLOCKS _PERCENT
Default: 10		 In-memory repopulate threshold blocks invalid percentage
TBD
_INMEMORY_REPOPULATE_THRESHOLD_MINTIME
Default: 0		 In-memory repopulate minimum interval (millisec)
TBD
_INMEMORY_REPOPULATE_THRESHOLD_MINTIME _FACTOR
Default: 5		 In-memory repopulate minimum interval (N*timetorepop)
TBD
_INMEMORY_REPOPULATE_THRESHOLD_ROWS
Default:<NULL> 		In-memory repopulate threshold number of modified rows
TBD
_INMEMORY_REPOPULATE_THRESHOLD_ROWS -PERCENT
Default: 5		 In-memory repopulate threshold rows invalid percentage
TBD
_INMEMORY_REPOPULATE_THRESHOLD_SCANS
Default: 0		 In-memory repopulate threshold number of scans
TBD
_INMEMORY_RETENTION_TIME
Default: 120		 Maximum retention time of imcu after repopulation
TBD
_INMEMORY_ROWS_CHECK_INTERRUPT
Default: 1000		 Number of rows buffered before interrupt check
TBD
_INMEMORY_SCAN_INVALID_PERCENT
Default: 30		 Inmemory scan invalid percentage
TBD
_INMEMORY_SCAN_OVERRIDE
Default: FALSE		 In-memory scan override
TBD
_INMEMORY_SERVERS_THROTLE_PGALIM _PERCENT
Default: 55		 In-memory populate servers throttling pga limit percentage
TBD
_INMEMORY_SHARED_JOURNAL_MAXEXTS
Default: 1024		 Maximum number of extents per SJ
TBD
_INMEMORY_SHARED_JOURNAL_MINEXTS_REPOP
Default: 256		 Minimum number of extents per SJ to trigger repop
TBD
_INMEMORY_SMALL_SEGMENT _THRESHOLD
Default: 65536		 In-memory small segment threshold (must be larger for in-memory)
TBD
INMEMORY_SMU_PATCH_OPTIONS
Default: 7		 Inmemory SMU patching options
TBD
_INMEMORY_STRDLXID_TIMEOUT
Default: 0		 Max time to determine straddling transactions
TBD
_INMEMORY_SUBCU_HISTSIZE
Default: 0		 In-memory subCU Histogram size
TBD
_INMEMORY_SUBCUSIZE
Default: 512		 In-memory subCU size
TBD
_INMEMORY_SUPPRESS_VSGA_IMA
Default: FALSE		 Suppress inmemory area in v$sga
TBD
_INMEMORY_TEST_VERIFICATION
Default: 0		 In-memory verification testing
TBD
_INMEMORY_TRANSACTION_OPTIONS
Default: 2806		 In-memory transaction performance options
TBD
_INMEMORY_TRICKLE_REPOPULATE
Default: TRUE		 Enable inmemory trickle repopulate
TBD
_INMEMORY_TRICKLE_REPOPULATE_FG
Default: 0		 Trickle Repopulate in the Foreground
TBD
_INMEMORY_TRICKLE_REPOPULATE_MIN_INTERVAL
Default: 300		 IMCO Trickle Repopulate Interval
TBD
_INMEMORY_TRICKLE_REPOPULATE _THRESHOLD_DIRTY_RATIO
Default: 0		 IMCO Trickle Repopulate threshold dirty ratio
TBD
_INMEMORY_TXN_CHECKSUM
Default: 0		 Checksum for SMUs and private journals
TBD
_INMEMORY_TXNPJRNL_DEBUG
Default: 0		 Ttransaction privilege journal debugging parameter
TBD
_INMEMORY_VALIDATE_FETCH
Default: FALSE		 If true, validate single-row fetch between in-memory and disk
TBD
_INMEMORY_VECTOR_ENCODE _OVERRIDE
Default: FALSE		 Populate and use DSBs for Vector Encode columns
TBD
_INMEMORY_WAITINVIS_COUNT
Default: 8		 In-memory wait invisible retry count
TBD
_INMEMORY_XMEM_SIZE
Default: 0		 Size in bytes of in-memory xmem area
TBD
_OPTIMIZER_INMEMORY_ACCESS_PATH
Default: TRUE		 Optimizer access path costing for in-memory
TBD
_OPTIMIZER_INMEMORY_AUTODOP
Default: TRUE		 Optimizer autoDOP costing for in-memory
TBD
_OPTIMIZER_INMEMORY_BLOOM_FILTER
Default: TRUE		 Controls serial bloom filter for in-memory tables
TBD
_OPTIMIZER_INMEMORY_CAPTURE _STORED_STATS
Default: TRUE		 Optimizer capture and store statistics for in-memory tables
TBD
_OPTIMIZER_INMEMORY_CLUSTER _AWARE_DOP
Default: TRUE		 Affinitize DOP for inmemory objects
TBD
_OPTIMIZER_INMEMORY_GEN _PUSHABLE_PREDS
Default: TRUE		 Optimizer generate pushable predicates for in-memory
TBD
_OPTIMIZER_INMEMORY_MINMAX _PRUNING
Default: TRUE		 Controls use of min/max pruning for costing in-memory tables
TBD
_OPTIMIZER_INMEMORY_PRUNING _RATIO_ROWS
Default: 100		 In-memory pruning ratio for # rows (% of rows remaining after pruning)
TBD
_OPTIMIZER_INMEMORY_QUOTIENT
Default: 0		 In-memory quotient (% of rows in in-memory format)
TBD
_OPTIMIZER_INMEMORY_TABLE _EXPANSION
Default: TRUE		 Optimizer in-memory awareness for table expansion
TBD
_OPTIMIZER_INMEMORY_USE_STORED _STATS
Default: AUTO		 Optimizer use stored statistics for in-memory tables
TBD
_PARALLEL_INMEMORY_MIN_TIME _THRESHOLD
Default: AUTO		 Threshold above which a plan is a candidate for parallelization for in-memory tables (in seconds)
TBD
_PARALLEL_INMEMORY_TIME_UNIT
Default: 1		 Unit of work used to derive the degree of parallelism for in-memory tables (in seconds)
TBD
 
KCFIS
_KCFIS_AUTOMEM_LEVEL
Default: 1		 Set auto memory management control for kcfis memory allocation
TBD
_KCFIS_BLOCK_DUMP_LEVEL
Default: 0		 Smart IO block dump level
TBD
_KCFIS_BYTESWAP_OPT_DISABLED
Default: FALSE		 Don't use byte swapping optimization on the storage cell
TBD
_KCFIS_CACHING_ENABLED
Default: TRUE		 Enable kcfis intra-scan session caching
TBD
_KCFIS_CELL_PASSTHRU_DATAONLY
Default: TRUE		 Allow dataonly passthru for smart scan
TBD
_KCFIS_CELL_PASSTHRU_ENABLED
Default: FALSE		 Do not perform smart IO filtering on the cell
TBD
_KCFIS_CELL_PASSTHRU_FROMCPU_ENABLED
Default: TRUE		 Enable automatic passthru mode when cell CPU utilization is too high
TBD
_KCFIS_CELLCACHE_DISABLED
Default: FALSE		 Don't use cellcache rewrite optimization on the storage cell
TBD
_KCFIS_CELLOFLSRV_PASSTHRU_ENABLED
Default: FALSE		 Enable offload server usage for passthru operations
TBD
_KCFIS_CELLOFLSRV_USAGE_ENABLED
Default: TRUE		 Enable offload server usage for offload operations
TBD
_KCFIS_CONTROL1
Default: 0		 Control1
TBD
_KCFIS_CONTROL2
Default: 0		 Control2
TBD
_KCFIS_CONTROL3
Default: 0		 Control3
TBD
_KCFIS_CONTROL4
Default: 0		 Control4
TBD
_KCFIS_CONTROL5
Default: 0		 Control5
TBD
_KCFIS_CONTROL6
Default: 0		 Control6
TBD
_KCFIS_DISABLE_PLATFORM_ENCRYPTION
Default: FALSE		 Don't use platform-specific decryption on the storage cell
TBD
_KCFIS_DUMP_CORRUPT_BLOCK
Default: TRUE		 Dump any corrupt blocks found during smart IO
TBD
_KCFIS_FAST_RESPONSE_ENABLED
Default: TRUE		 Enable smart scan optimization for fast response (first rows)
TBD
_KCFIS_FAST_RESPONSE_INITIOSIZE
Default: 2		 Fast response - The size of the first IO in logical blocks
TBD
_KCFIS_FAST_RESPONSE_IOSIZEMULT
Default: 4		 Fast response - (next IO size = current IO size * this parameter)
TBD
_KCFIS_FAST_RESPONSE_THRESHOLD
Default: 1048576		 Fast response - the number of IOs after which smartIO is used
TBD
_KCFIS_FASTFILEINIT_DISABLED
Default: FALSE		 Don't use ffi during file creation
TBD
_KCFIS_FAULT_CONTROL
Default: 0		 Fault Injection Control
TBD
_KCFIS_IO_PREFECTCH_SIZE
Default: 8		 Smart IO prefetch size for a cell
TBD
_KCFIS_IOREQS_THROTTLE_ENABLED
Default: TRUE		 Enable Smart IO requests throttling
TBD
_KCFIS_KEPT_IN_CELLFC_ENABLED
Default: TRUE		 Enable usage of cellsrv flash cache for kept objects
TBD
_KCFIS_LARGE_PAYLOAD_ENABLED
Default: FALSE		 Enable large payload to be passed to cellsrv
TBD
_KCFIS_MAX_CACHED_SESSIONS
Default: 10		 Sets the maximum number of kcfis sessions cached
TBD
_KCFIS_MAX_OUT_TRANSLATIONS
Default: 5000		 Sets the maximum number of outstanding translations in kcfis
TBD
_KCFIS_NONDEPT_IN_CELLFC_ENABLED
Default: FALSE		 Enable use of cellsrv flash cache for non-kept objects
TBD
_KCFIS_OSS_IO_SIZE
Default: 0		 KCFIS OSS I/O size
TBD
_KCFIS_PMEM_ENABLED
Default: TRUE		 RDMA Persistent Memory support enabled
TBD
_KCFIS_QM_PRIORITIZE_SYS_PLAN
Default: TRUE		 Prioritize Quarantine Manager system plan
TBD
_KCFIS_QM_USER_PLAN_NAME
Default: <NULL>		 Quarantine Manager user plan name
TBD
_KCFIS_RDBMS_BLOCKIO_ENABLED
Default: FALSE		 Use block IO instead of smart IO in the smart IO module on RDBMS
TBD
_KCFIS_READ_BUFFER_LIMIT
Default: 0		 KCFIS Read Buffer (per session) memory limit in bytes
TBD
_KCFIS_SPAWN_DEBUGGER
Default: FALSE		 Decides whether to spawn the debugger at kcfis initialize
TBD
_KCFIS_STATS_LEVEL
Default: 0		 _kcfis_stats_level 0 sets kcfis stats level
TBD
_KCFIS_STORAGEIDX_DIAG_MODE
Default: 0		 Debug mode for storage index on the cell
TBD
_KCFIS_STORAGEIDX_DISABLED
Default: FALSE		 Don't use storage index optimization on the storage cell
TBD
_KCFIS_STORAGEIDX_SET_MEMBERSHIP _DISABLED
Default: FALSE		 Don't use set membership optimization on the storage cell
TBD
_KCFIS_STORAGEIDX_XTSS_DISABLED
Default: FALSE		 Don't use storage index optimization on the storage cell for XTSS
TBD
_KCFIS_TEST_CONTROL
Default: 0		 kcfis tst control1
TBD
_KCFIS_TRACE_BUCKET_SIZE
Default: 131072		 KCFIS tracing bucket size in bytes
TBD
_KCFIS_XTGRAN_PREFETCH_COUNT
Default: 1		 External Table Smart Scan granule prefetch count
TBD
13 OF 25
ZZZ
?
Default: 		?
TBD
 
ZZZ
?
Default: 		?
TBD

Related Topics
DBMS_WORKLOAD_REPOSITORY
INIT.ORA & SPFILE
Synonyms
Underscore Parameters: Page 1 of 5
Underscore Parameters: Page 2 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