Hidden Parameters in Oracle AI Database 26ai H.8 AI Vector Search (171)

 

Name	Type	Value	At default?	Level	PDB	RAC inst.	Flags	Description
_vector_accuracy_report_sample_size	Integer	25	yes	SESSION	Y	Y		vector accuracy report sample size
_vector_aggregation_max_size	Integer	0	yes	SESSION	Y	Y		max size of vector aggregation space
_vector_autogrow_sga_percent	Integer	70	yes	SYSTEM imm.	Y	Y		Vector max memory size as SGA percent
_vector_debug	Integer	0	yes	SYSTEM imm.	N	Y		IMA vector memory debug
_vector_dense_accum_max	Integer	100	yes	SESSION	Y	Y		vector group by dense accumulator space max
_vector_distance_metric_default	String	COSINE	yes	SESSION	Y	Y		vector distance metric
_vector_encoding_mode	String	MANUAL	yes	SESSION	Y	Y		enable vector encoding(OFF/MANUAL/AUTO)
_vector_hnsw_cancel_ingest_task_retry	Integer	5	yes	SESSION	Y	Y		Vector HNSW index cancel ingest task retries
_vector_hnsw_cancel_ingest_task_timeout	Integer	5	yes	SESSION	Y	Y		Vector HNSW index cancel ingest task timout in sec
_vector_hnsw_enable_heuristic	Boolean	TRUE	yes	SESSION	Y	Y		If true, the heuristic neighbor selection is enabled in HNSW
_vector_hnsw_force_seq_ingestion	Boolean	FALSE	yes	SESSION	N	N		If true, the HNSW is loaded sequentially
_vector_hnsw_load_batch_size	Integer	500	yes	SESSION	N	N		Vector HNSW index ingestion batch size
_vector_hnsw_max_svecs	Integer	0	yes	SESSION	Y	Y		Maximum number of sample vectors to be evaluated for the neighbor graph collection statistics process
_vector_hnsw_mem_overestimate_percent	Integer	10	yes	SESSION	N	N		Vector HNSW index memory overestimate percentage
_vector_hnsw_promotion_strategy	Integer	1	yes	SESSION	Y	Y		Vector HNSW index vector promotion strategy
_vector_hnsw_sparse_threshold	Integer	5000000	yes	SESSION	N	N		Vector HNSW index sparse bitset usage threshold
_vector_hnsw_stats_cache_enable	Boolean	TRUE	yes	SESSION	Y	Y		Vector HNSW index statistics collection with cache
_vector_hnsw_stats_cache_mem_percent	Integer	5	yes	SESSION	Y	Y		Vector HNSW index statistics collection memory percentage for cache
_vector_hnsw_stats_enable_accmap	Boolean	FALSE	yes	SESSION	N	N		Enable/disable the neighbor graph accuracy map usage
_vector_hnsw_verification_lvl	Integer	0	yes	SESSION	Y	Y		Vector HNSW index verification level
_vector_index_active_partition_purge_count	Integer	1000	yes	SYSTEM imm.	Y	Y		vector index active partition purge count
_vector_index_calibration_dvsz	Integer	5000	yes	SESSION	Y	Y		Data vector batch size used for calibrating vector indexes
_vector_index_cc_dml_support	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		enable/disable vector index covering columns dml support
_vector_index_change_log_driven_scan_threshold	Integer	1000	yes	SESSION	Y	Y		threshold of using change log driven scan query
_vector_index_cleanup_build	String	BACKGROUND	yes	SYSTEM imm.	Y	Y		Vector index build cleanup
_vector_index_cleanup_inline	Boolean	TRUE	yes	SESSION	Y	Y	deprecated	Vector index inline cleanup
_vector_index_compute_statistics	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		enable/disable vector index compute statistics
_vector_index_ddl_deadlock_prevention_timeout	Integer	15000000	yes	SESSION	Y	Y		vector index deadlock prevention timeout usec
_vector_index_disable_directload	Boolean	FALSE	yes	SESSION	Y	Y		disable direct load operations on tables with vector indexes
_vector_index_disable_pmop	Boolean	FALSE	yes	SESSION	Y	Y		disable partition management operations on tables with vector indexes
_vector_index_dist_txn_support	Boolean	TRUE	yes	STATIC	N	N		vector support dist txn with hnsw index
_vector_index_elastic_memory	Integer	0	yes	SESSION	Y	Y		vector index hnsw elastic memory flags
_vector_index_flush_batch_size	Integer	1024	yes	STATIC	N	N		vector index private journal array flush size
_vector_index_hnsw_buffer_lvector	Boolean	FALSE	yes	SESSION	Y	Y		Vector HNSW index buffer lvectors
_vector_index_hnsw_checkpoint_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector hnsw index checkpoints enable
_vector_index_hnsw_checkpoint_rac_duplication	Boolean	TRUE	yes	SESSION	Y	Y		vector hnsw index reload using checkpoints in rac duplication
_vector_index_hnsw_checkpoint_refresh	String	AUTO	yes	SESSION	Y	Y		specifies checkpoint creation policy during index refresh
_vector_index_hnsw_checkpoint_reload_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector hnsw index reload using checkpoints enable
_vector_index_hnsw_checkpoint_snapshot_threshold	Integer	0	yes	SYSTEM imm.	Y	Y		vector hnsw index checkpoint snapshot threshold number
_vector_index_hnsw_checkpoint_snapshot_time_ratio	Integer	50	yes	SYSTEM imm.	Y	Y		vector hnsw index checkpoint snapshot build time ratio percentage
_vector_index_hnsw_cursor_invalidation	Integer	63	yes	SESSION	Y	Y		vector index hnsw cursor invalidation flags
_vector_index_hnsw_dist_enable	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		vector distributed hnsw index enable
_vector_index_hnsw_dist_graph_metadata_usage_enable	Boolean	FALSE	yes	SESSION	Y	Y		vector distributed hnsw graph metadata usage enable
_vector_index_hnsw_dist_nvec_inflate_pct	Integer	20	yes	SESSION	Y	Y		vector distributed hnsw approximate vector inflate percent
_vector_index_hnsw_dist_rac_disable_index_ktsjq_retries	Integer	3	yes	SYSTEM imm.	Y	Y		vector index hnswd rac disable index ktsjq retries
_vector_index_hnsw_dist_rac_leader_stepdown_tout_multiplier	Integer	60	yes	SYSTEM imm.	Y	Y		vector index hnswd rac leader stepdown multiplier
_vector_index_hnsw_dist_rac_rcfg_index_open_graph_reply_wait	Integer	60	yes	SYSTEM imm.	Y	Y		vector index hnswd rac rcfg index poll reply wait
_vector_index_hnsw_dist_rac_rcfg_index_poll_reply_wait	Integer	60	yes	SYSTEM imm.	Y	Y		vector index neighbor graph refresh rac poll reply wait
_vector_index_hnsw_dist_rac_rcfg_kick_reply_wait	Integer	50	yes	SYSTEM imm.	Y	Y		vector index hnswd rac reconfig kick reply wait
_vector_index_hnsw_dist_rac_rcfg_poll_nap_time_between_epochs	Integer	30	yes	SYSTEM imm.	Y	Y		vector index hnswd rac rcfg poll nap time between epochs
_vector_index_hnsw_dist_rac_rebuild_rcfg_threshold	Integer	3	yes	SESSION	Y	Y		vector index hnswd rac rebuild rcfg threshold
_vector_index_hnsw_dist_rac_reconfig	Integer	1	yes	SYSTEM imm.	Y	Y		vector index hnsw dist rac reconfig
_vector_index_hnsw_dist_rac_reconfig_dbg	Integer	0	yes	SYSTEM imm.	Y	Y		vector index hnsw dist rac reconfig dbg
_vector_index_hnsw_dist_rac_redist_rcfg_threshold	Integer	25	yes	SYSTEM imm.	Y	Y		vector index hnswd rac redist rcfg threshold
_vector_index_hnsw_dist_rac_redistribute_poll_local_q_size	Integer	16	yes	SYSTEM imm.	Y	Y		vector index hnswd rac redistribute poll localq size
_vector_index_hnsw_dist_rac_redistribute_poll_retry_count	Integer		yes	SYSTEM imm.	Y	Y		vector index neighbor graph refresh rac poll retry count
_vector_index_hnsw_dist_redist_info_wait	Integer	180	yes	SYSTEM imm.	Y	Y		vector index neighbor graph send redist info reply wait
_vector_index_hnsw_dist_repopulation_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector distributed hnsw repopulation enable
_vector_index_hnsw_dist_snapshot_enable	Boolean	FALSE	yes	SESSION	Y	Y		vector distributed hnsw snapshot enable
_vector_index_hnsw_dist_stubs_enable	Boolean	FALSE	yes	SYSTEM imm.	Y	Y		vector distributed hnsw index stubs enable
_vector_index_hnsw_distribution_unit_boundary_estimate	Integer	0	yes	SESSION	Y	Y		vector distributed hnsw index distribution unit boundary estimate
_vector_index_hnsw_distribution_unit_memory_limit	Integer	16	yes	SESSION	Y	Y		vector distributed hnsw index distribution unit memory limit
_vector_index_hnsw_dml_trigger_mode	Integer	3	yes	SESSION	Y	Y		vector index neighbor graph dml triger mode
_vector_index_hnsw_drop_intent_poll_retry_count	Integer	300	yes	SESSION	Y	Y		vector index neighbor graph drop intent poll retry count
_vector_index_hnsw_enable_local_hnsw_rac	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Enable/disable local HNSW vector index on RAC
_vector_index_hnsw_funcbased_enable	Boolean	TRUE	yes	SESSION	Y	Y		function-based vector index enable (hnsw)
_vector_index_hnsw_included_columns_enable	Boolean	TRUE	yes	SESSION	Y	Y		HNSW index included columns enabled
_vector_index_hnsw_included_columns_snapshot_enable	Boolean	FALSE	yes	SESSION	Y	Y		HNSW index included columns snapshot enabled
_vector_index_hnsw_local_enable	Boolean	TRUE	yes	SESSION	Y	Y		Enable/Disable local HNSW index
_vector_index_hnsw_offload_enabled	Boolean	TRUE	yes	SESSION	Y	Y		Allow HNSW index creation offload using Accelerated Compute
_vector_index_hnsw_on_external_table	Boolean	FALSE	yes	SESSION	Y	Y		Enable/Disable creation of HNSW on external table
_vector_index_hnsw_online_build_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector index hnsw online build enable
_vector_index_hnsw_optimizations	Integer	1	yes	SESSION	Y	Y		Vector index HNSW optimizations
_vector_index_hnsw_parallel_build_index_flag	Integer	0	yes	SESSION	Y	Y		vector hnsw parallel build index flag
_vector_index_hnsw_pdb_open_reload	Boolean	FALSE	yes	SYSTEM imm.	Y	Y		vector index reload during pdb open enable
_vector_index_hnsw_pdb_open_reload_timeout	Integer	600	yes	SYSTEM imm.	Y	Y		vector index hnsw reload timeout (in seconds)
_vector_index_hnsw_quiesce_readers_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector hnsw index refcount wait enable
_vector_index_hnsw_rac_duplication	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Duplicate HNSW in-memory on all instances
_vector_index_hnsw_rac_poll_interval	Integer	30	yes	SYSTEM imm.	Y	Y		Duplicate HNSW in-memory on RAC Poll timeout
_vector_index_hnsw_rac_poll_interval_short	Integer	1	yes	SYSTEM imm.	Y	Y		Duplicate HNSW in-memory on RAC short Poll timeout
_vector_index_hnsw_rac_retry_count	Integer	10	yes	SYSTEM imm.	Y	Y		Duplicate HNSW in-memory on RAC retry count
_vector_index_hnsw_range_predicated_sql_max_bind	Integer	500	yes	SESSION	Y	Y		vector distributed hnsw index range predicated sql rpi max binds
_vector_index_hnsw_refcount_tracking	Integer	0	yes	SYSTEM imm.	Y	Y		vector hnsw index refcount holder tracking enable
_vector_index_hnsw_refresh_rac_poll_retry_count	Integer		yes	SESSION	Y	Y		vector index neighbor graph refresh rac poll retry count
_vector_index_hnsw_refresh_recovery_mode	Integer	1	yes	SESSION	Y	Y		vector index neighbor graph refresh recovery mode
_vector_index_hnsw_refresh_retention	Integer	900	yes	SESSION	Y	Y		HNSW vector index graph refresh retention threshold
_vector_index_hnsw_refresh_retention_enable	String	SNAPSHOT_CAPABLE_INDEXES	yes	SESSION	Y	Y		HNSW vector index graph refresh retention mode
_vector_index_hnsw_repop_retry_count	Integer	3	yes	SESSION	Y	Y		vector index neighbor graph repopulate create table retry count
_vector_index_hnsw_repopulate_percent_factor	Integer	1	yes	SESSION	Y	Y		vector index neighbor graph repopulate percentage factor
_vector_index_hnsw_repopulate_threshold_count	Integer	100000	yes	SESSION	Y	Y		vector index neighbor graph repopulate threshold count
_vector_index_hnsw_scalar_quantization_enabled	Boolean	TRUE	yes	SESSION	Y	Y		HNSW vector index scalar quantization enable
_vector_index_hnsw_snapshot_rac_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector index neighbor graph snapshot rac enable
_vector_index_hnsw_snapshot_threshold_count	Integer	10000	yes	SESSION	Y	Y		vector index neighbor graph snapshot threshold count
_vector_index_hnsw_snapshot_threshold_shrink_quota	Integer	100	yes	SESSION	Y	Y		vector index neighbor graph snapshot shrink quota threshold MB
_vector_index_hnsw_stats_refresh_threshold	Integer		yes	SESSION	Y	Y		vector index neighbor graph stats refresh snapshot threshold
_vector_index_hnsw_test_flags	Integer	0	yes	SYSTEM imm.	Y	Y		vector hnsw index test
_vector_index_internal_table_drop_retry_interval	Integer	100	yes	SESSION	Y	Y		vector hnsw index internal table drop retry interval
_vector_index_ivf_alert_threshold	Integer	10000	yes	SESSION	Y	Y		Threshold on the number of non-null vectors for creating vector indexes
_vector_index_ivf_allow_window_func_rpi_on_sage	Boolean	FALSE	yes	SYSTEM imm.	Y	Y		Allow RPI for IVF window/non-window functions on Sage
_vector_index_ivf_cc_online_re_build_enabled	Boolean	TRUE	yes	SESSION	Y	Y		Enable/Disable online creation/rebuild of IVF indexes with covering columns
_vector_index_ivf_centroid_partition_target_size	Integer	200	yes	SESSION	Y	Y		The target partition size for centroid partition table
_vector_index_ivf_centroids_assignment_mode	String	AUTO	yes	SESSION	Y	Y		IVF compute mode
_vector_index_ivf_centroids_in_large_pool	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Populate inmemory centroids in large pool for the IVF vector index
_vector_index_ivf_centroids_recovery_test_flags	Integer	0	yes	SESSION	Y	Y		IVF centroids recovery test flags
_vector_index_ivf_centroids_recovery_test_mode	Integer	0	yes	SESSION	Y	Y		IVF centroids recovery test mode
_vector_index_ivf_covering_columns	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Enable covering columns for IVF index to be used in queries
_vector_index_ivf_covering_columns_partitioned_table	Boolean	TRUE	yes	SESSION	Y	Y		IVF index covering columns from partitioned table enabled
_vector_index_ivf_deterministic_centroids	Boolean	FALSE	yes	SESSION	Y	Y		Enable deterministic centroids creation for vector IVF index
_vector_index_ivf_disk_format	Integer	1	yes	SESSION	Y	Y		On-disk compress format for vector index
_vector_index_ivf_enable_local_index	Boolean	TRUE	yes	SESSION	Y	Y		enable/disable vector index local index
_vector_index_ivf_flashcache_format	Integer	1	yes	SESSION	Y	Y		Flashcache compress format for vector index
_vector_index_ivf_funcbased_enable	Boolean	FALSE	yes	SESSION	Y	Y		function-based vector index enable (ivf)
_vector_index_ivf_im_centroids_in_dmls	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Use inmemory centroids in dmls that maintain IVF vector index
_vector_index_ivf_im_centroids_in_queries	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Use inmemory centroids in queries that use IVF vector index
_vector_index_ivf_init_model_arg	Integer	0	yes	SESSION	Y	Y		The argument for initializing the model of a vector index partition
_vector_index_ivf_init_model_method	Integer	1	yes	SESSION	Y	Y		Method to initialize the model for a newly added vector index partition
_vector_index_ivf_initrans	Integer	0	yes	SESSION	Y	Y		The setting of INITRANS for creating centroid partition table
_vector_index_ivf_journal_replay_iteration	Integer	3	yes	SESSION	Y	Y		vector ivf index journal replay iteration
_vector_index_ivf_local_included_columns	Boolean	TRUE	yes	SESSION	Y	Y		Enable covering columns in local IVF index
_vector_index_ivf_local_index_rewrite_level	Integer	3	yes	SESSION	Y	Y		vector index local index rewrite level
_vector_index_ivf_local_min_rows_scan	Integer	10240	yes	SESSION	Y	Y		the minimal number of rows to be scanned in local IVF queries
_vector_index_ivf_maint_on_iceberg_max_parallel_tasks	Integer	1	yes	SESSION	Y	Y		Max KTSJ submission limit for IVF maintenance tasks
_vector_index_ivf_on_external_table	Boolean	FALSE	yes	SESSION	Y	Y		Enable/Disable creation of IVF on external table
_vector_index_ivf_on_iceberg_external_table	String	CATALOG	yes	SESSION	Y	Y		Control creation of IVF on Iceberg external table
_vector_index_ivf_online_build_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector index ivf online build enable
_vector_index_ivf_online_catchup_mode	Integer	0	yes	SESSION	Y	Y		IVF catchup mode
_vector_index_ivf_optim_cache_time	Integer	600	yes	SESSION	Y	Y		vector index optimization background parameter cache frequency
_vector_index_ivf_partition_algorithm	Integer	1	yes	SESSION	Y	Y		Partitioning method for creating centroid partition table
_vector_index_ivf_partition_number	Integer	0	yes	SESSION	Y	Y		The number of partitions for creating centroid partition table
_vector_index_ivf_partition_size	String	AUTO	yes	SESSION	Y	Y		The preferred partition size for the IVF centroid partition table
_vector_index_ivf_pctfree	Integer	1	yes	SESSION	Y	Y		Physcial attribute PCTFREE for creating vector index
_vector_index_ivf_populate_im_centroids	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		Populate inmemory centroids for the IVF vector index
_vector_index_ivf_refcount_tracking	Boolean	TRUE	yes	SESSION	Y	Y		IVF centroids reference count tracking enable
_vector_index_ivf_sample_size	Integer	0	yes	SESSION	Y	Y		vector ivf index sample size
_vector_index_ivf_sparse	Boolean	TRUE	yes	SESSION	Y	Y		Enable creation of SPARSE IVF index
_vector_index_ivf_test_flags	Integer	0	yes	SESSION	Y	Y		IVF vector index test
_vector_index_ivf_use_window_func_rpi	Boolean	FALSE	yes	SYSTEM imm.	Y	Y		Enable RPI for IVF window/non-window functions
_vector_index_journaling	Boolean	TRUE	yes	SYSTEM imm.	Y	Y		enable/disable vector index journaling
_vector_index_max_bg_query_exec_time	Integer	300000	yes	SYSTEM imm.	Y	Y		vector index max bg query execution time
_vector_index_minact_max_wait	Integer	10	yes	SYSTEM imm.	Y	Y		vector index minact max wait time sec
_vector_index_neighbor_graph_refresh	String	AUTO	yes	SESSION	Y	Y		vector index neighbor graph refresh mode
_vector_index_online_build_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector index online build enable
_vector_index_online_catchup_iterations	Integer	5	yes	SESSION	Y	Y		vector index online catchup iteration count
_vector_index_online_catchup_timeout	Integer	0	yes	SESSION	Y	Y		vector index online catchup timeout percentage
_vector_index_online_dml_threshold_count	Integer	1000	yes	SESSION	Y	Y		vector index online build dml drain threshold count
_vector_index_online_local_rebuild_enable	Boolean	TRUE	yes	SESSION	Y	Y		local vector index online rebuild enable
_vector_index_online_rebuild_enable	Boolean	TRUE	yes	SESSION	Y	Y		vector index online rebuild enable
_vector_index_parallel_degree_limit	Integer	0	yes	SESSION	Y	Y		Parallel degree limit for creating a vector index
_vector_index_parallel_dml	String	ENABLED	yes	SESSION	Y	Y		PDML configuration for vector indexes
_vector_index_parallel_mm	Boolean	TRUE	yes	SESSION	Y	Y		Enable/Disable parallel MM optimization for vector index stats
_vector_index_partition_staleness_threshold	Integer	2	yes	SYSTEM imm.	Y	Y		vector index partition staleness threshold
_vector_index_quiesce_readers_timeout	Integer	300	yes	SESSION	Y	Y		vector index refcount wait timeout
_vector_index_scan_extra_monitor_hint	String		yes	SESSION	Y	Y		vector index scan extra monitor hint
_vector_index_scan_use_change_log_driven	Boolean	TRUE	yes	SESSION	Y	Y		enable/disable use of change log driven scan query
_vector_index_scan_use_expand_table_hint	Boolean	FALSE	yes	SESSION	Y	Y		enable/disable using expand table hint
_vector_index_scan_use_monitor_hint	Boolean	FALSE	yes	SESSION	Y	Y		enable/disable vector index scan monitor hint
_vector_index_space_grow_percent	Integer	3	yes	SYSTEM imm.	Y	Y		Percentage of space to be grown at a time for Private Journal using background grow API
_vector_index_space_grow_threshold	Integer	80	yes	SYSTEM imm.	Y	Y		Percentage of space utilization threshold to reach before calling the background grow API
_vector_index_stats_use_enabled	Boolean	FALSE	yes	SESSION	Y	Y		Enable/Disable use of vector index stats
_vector_index_test_flags	Integer	0	yes	SESSION	Y	Y		vector index journaling test flags
_vector_index_time_staleness_factor	Integer	90	yes	SYSTEM imm.	Y	Y		vector index time staleness factor (percentage)
_vector_index_use_mm_for_stats	Boolean	TRUE	yes	SESSION	Y	Y		Enable/Disable use of MM optimization for vector index stats
_vector_insert_scan_use_sorted_dist	Boolean	FALSE	yes	SESSION	Y	Y		enable/disable insert query using sorted dist
_vector_journal_fxt_tab_size	Integer	100	yes	STATIC	N	N		vector journal fixed table size
_vector_memory_64k_percent	Integer	10	yes	STATIC	N	N		percentage of vector memory area for 64k pools
_vector_operations_control	Integer	0	yes	SESSION	Y	Y		control different uses/algorithms related to vector transform
_vector_private_journal_maxexts	Integer	1000	yes	SYSTEM imm.	Y	Y		Max number of extents from 1MB pool per vector PJ
_vector_query_capture_area_size	Integer	100	yes	SYSTEM imm.	Y	Y		Memory budget allowed for vector query capture feature
_vector_query_capture_interval	Integer	1	yes	SESSION	Y	Y		Sampling interval for query vector capture in seconds
_vector_query_capture_retention_days	Integer	7	yes	SYSTEM imm.	Y	Y		Query vectors will be stored till retention period
_vector_serialize_temp_threshold	Integer	1000	yes	SESSION	Y	Y		threshold for serializing vector transform temp table writes