SecureFile LOB - spfile parameters

Here is a list of all the spfile parameters I found (and guess are) related to SecureFile LOBs.

This Post will be updated with additional information whenever I collect them.

Parameter	Default value	Description
_dbfs_modify_implicit_fetch	TRUE 12.1.0.2	DBFS Link allows implicit fetch on modify - only on SecureFiles
_enable_securefile_flashback_opt	FALSE 12.1.0.2	Enable securefile flashback optimization
_kdli_STOP_bsz	0 12.1.0.2	undocumented parameter for internal use only
_kdli_STOP_dba	0 12.1.0.2	undocumented parameter for internal use only
_kdli_STOP_fsz	0 12.1.0.2	undocumented parameter for internal use only
_kdli_STOP_nio	0 12.1.0.2	undocumented parameter for internal use only
_kdli_STOP_tsn	0 12.1.0.2	undocumented parameter for internal use only
_kdli_allow_corrupt	TRUE 12.1.0.2	allow corrupt filesystem_logging data blocks during read/write
_kdli_buffer_inject	TRUE 12.1.0.2	use buffer injection for CACHE [NO]LOGGING lobs
_kdli_cache_inode	TRUE 12.1.0.2	cache inode state across calls
_kdli_cache_read_threshold	0 12.1.0.2	minimum lob size for cache->nocache read (0 disables heuristic)
_kdli_cache_size	8 12.1.0.2	maximum #entries in inode cache
_kdli_cache_verify	FALSE 12.1.0.2	verify cached inode via deserialization
_kdli_cache_write_threshold	0 12.1.0.2	minimum lob size for cache->nocache write (0 disables heuristic)
_kdli_cacheable_length	0 12.1.0.2	minimum lob length for inode cacheability
_kdli_checkpoint_flush	FALSE 12.1.0.2	do not invalidate cache buffers after write
_kdli_dbc	none 12.1.0.2	override db_block_checking setting for securefiles
_kdli_delay_flushes	TRUE 12.1.0.2	delay flushing cache writes to direct-write lobs
_kdli_descn_adj	FALSE 12.1.0.2	coalesce extents with deallocation scn adjustment
_kdli_flush_cache_reads	FALSE 12.1.0.2	flush cache-reads data blocks after load
_kdli_flush_injections	TRUE 12.1.0.2	flush injected buffers of CACHE NOLOGGING lobs before commit
_kdli_force_cr	TRUE 12.1.0.2	force CR when reading data blocks of direct-write lobs
_kdli_force_cr_meta	TRUE 12.1.0.2	force CR when reading metadata blocks of direct-write lobs
_kdli_force_storage	none 12.1.0.2	force storage settings for all lobs
_kdli_full_readahead_threshold	0 12.1.0.2	maximum lob size for full readahead
_kdli_inject_assert	0 12.1.0.2	inject asserts into the inode
_kdli_inject_batch	0 12.1.0.2	buffer injection batch size [1, KCBNEWMAX]
_kdli_inject_crash	0 12.1.0.2	inject crashes into the inode
_kdli_inline_xfm	TRUE 12.1.0.2	allow inline transformed lobs
_kdli_inode_preference	data 12.1.0.2	inline inode evolution preference (data, headless, lhb)
_kdli_inplace_overwrite	0 12.1.0.2	maximum inplace overwrite size (> chunksize)
_kdli_itree_entries	0 12.1.0.2	#entries in lhb/itree blocks (for testing only)
_kdli_memory_protect	FALSE 12.1.0.2	trace accesses to inode memory outside kdli API functions
_kdli_mts_so	TRUE 12.1.0.2	use state objects in shared server for asyncIO pipelines
_kdli_oneblk	FALSE 12.1.0.2	allocate chunks as single blocks
_kdli_preallocation_mode	length 12.1.0.2	preallocation mode for lob growth
_kdli_preallocation_pct	0 12.1.0.2	percentage preallocation [0 .. inf) for lob growth
_kdli_ralc_length	10485760 12.1.0.2	lob length threshold to trigger rounded allocations
_kdli_ralc_rounding	1048576 12.1.0.2	rounding granularity for rounded allocations
_kdli_rci_lobmap_entries	255 12.1.0.2	#entries in RCI lobmap before migration to lhb
_kdli_readahead_limit	0 12.1.0.2	shared/cached IO readahead limit
_kdli_readahead_strategy	contig 12.1.0.2	shared/cached IO readahead strategy
_kdli_recent_scn	FALSE 12.1.0.2	use recent (not dependent) scns for block format/allocation
_kdli_reshape	FALSE 12.1.0.2	reshape an inode to inline or headless on length truncation
_kdli_safe_callbacks	TRUE 12.1.0.2	invoke inode read/write callbacks safely
_kdli_sio_async	TRUE 12.1.0.2	asynchronous shared IO
_kdli_sio_backoff	FALSE 12.1.0.2	use exponential backoff when attempting SIOP allocations
_kdli_sio_bps	0 12.1.0.2	maximum blocks per IO slot
_kdli_sio_dop	2 12.1.0.2	degree-of-parallelism in the SIO keep pool
_kdli_sio_fbwrite_pct	35 12.1.0.2	percentage of buffer used for direct writes in flashback-db
_kdli_sio_fgio	TRUE 12.1.0.2	reap asynchronous IO in the foreground
_kdli_sio_fileopen	none 12.1.0.2	shared IO fileopen mode: datasync vs nodatasync vs async
_kdli_sio_flush	FALSE 12.1.0.2	enable shared IO pool operations
_kdli_sio_free	TRUE 12.1.0.2	free IO buffers when not in active use
_kdli_sio_min_read	0 12.1.0.2	shared IO pool read threshold
_kdli_sio_min_write	0 12.1.0.2	shared IO pool write threshold
_kdli_sio_nbufs	8 12.1.0.2	maximum #IO buffers to allocate per session
_kdli_sio_niods	8 12.1.0.2	maximum #IO descriptors to allocate per session
_kdli_sio_on	TRUE 12.1.0.2	enable shared IO pool operations
_kdli_sio_pga	FALSE 12.1.0.2	use PGA allocations for direct IO
_kdli_sio_pga_top	FALSE 12.1.0.2	PGA allocations come from toplevel PGA heap
_kdli_sio_strategy	extent 12.1.0.2	shared IO strategy: block vs. extent
_kdli_sio_write_pct	100 12.1.0.2	percentage of buffer used for direct writes
_kdli_small_cache_limit	32 12.1.0.2	size limit of small inode cache
_kdli_sort_dbas	FALSE 12.1.0.2	sort dbas during chunkification
_kdli_space_cache_limit	2048 12.1.0.2	maximum #blocks in per-segment space cache
_kdli_space_cache_segments	16 12.1.0.2	#segments in space cache
_kdli_squeeze	TRUE 12.1.0.2	compact lobmap extents with contiguous dbas
_kdli_timer_dmp	FALSE 12.1.0.2	dump inode timers on session termination
_kdli_timer_trc	FALSE 12.1.0.2	trace inode timers to uts/tracefile
_kdli_trace	0 12.1.0.2	inode trace level
_kdli_vll_direct	TRUE 12.1.0.2	use skip-navigation and direct-positioning in vll-domain
_kdlxp_dedup_hash_algo	SHA1 12.1.0.2	secure hash algorithm for deduplication - only on SecureFiles
_kdlxp_lobcmpadp	FALSE 12.1.0.2	enable adaptive compression - only on SecureFiles
_kdlxp_lobcmplevel	2 12.1.0.2	Default securefile compression
_kdlxp_lobcmprciver	1 12.1.0.2	Default securefile compression map version
_kdlxp_lobcompress	FALSE 12.1.0.2	enable lob compression - only on SecureFiles
_kdlxp_lobdeduplicate	FALSE 12.1.0.2	enable lob deduplication - only on SecureFiles
_kdlxp_lobdedupvalidate	TRUE 12.1.0.2	enable deduplicate validate - only on SecureFiles
_kdlxp_lobencrypt	FALSE 12.1.0.2	enable lob encryption - only on SecureFiles
_kdlxp_mincmp	20 12.1.0.2	minimum comp ratio in pct - only on SecureFiles
_kdlxp_mincmplen	200 12.1.0.2	minimum loblen to compress - only on SecureFiles
_kdlxp_uncmp	FALSE 12.1.0.2	lob data uncompressed - only on SecureFiles
_kdlxp_xfmcache	TRUE 12.1.0.2	enable xfm cache - only on SecureFiles
_securefile_log_num_latches	0 12.1.0.2	Maximum number of open descriptors for securefile log
_securefile_log_shared_pool_size	0 12.1.0.2	Size of securefile log buffer pool from SGA
_securefile_timers	FALSE 12.1.0.2	collect kdlu timers and accumulate per layers
_securefiles_breakreten_retry	5 12.1.0.2	segment retry before dishonoring retention
_securefiles_bulkinsert	FALSE 12.1.0.2	securefiles segment insert only optization
_securefiles_concurrency_estimate	12 12.1.0.2	securefiles concurrency estimate
_securefiles_fg_retry	100 12.1.0.2	segment retry before foreground waits
_securefiles_forceflush	FALSE 12.1.0.2	securefiles force flush before allocation
_securefiles_memory_percentofSGA	8 12.1.0.2	securefiles memory as percent of SGA
_securefiles_spcutl	FALSE 12.1.0.2	securefiles segment utl optimization
_sf_default_enabled	TRUE 12.1.0.2	enable 12g securefile default
db_securefile	ALWAYS 12.1.0.2	permit securefile storage during lob creation

---

_kdli_trace

Seems to be a bitmap of flags.
the only value visible in MOS is

alter session set "_kdli_trace"=257;

Also used together with

alter session set "_securefile_timers"=true;
alter session set "_kdli_timer_dmp"=true;
alter session set events '10046 trace name context forever,level 12';
alter session set events '45050 trace name context forever, level  2056';
-- Event 45050 level 0x808 (Space event)

Bug 17283676 : MOVE LOB EXTREMELY SLOW

---

_securefiles_concurrency_estimate

Securefiles DMLs cause high 'buffer busy waits' & 'enq: TX - contention' wait events leading to whole database performance degradation (Doc ID 1532311.1)

---