_add_col_optim_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Allows new add column optimization |
_add_nullable_column_with_default_optim | Boolean | TRUE | yes | SESSION | Y | Y | | Allows add of a nullable column with default optimization |
_aged_out_cursor_cache_time | Integer | 300 | yes | SESSION | Y | N | | number of seconds an aged out session cached cursor stay in cache |
_aggregation_optimization_settings | Integer | 0 | yes | SESSION | Y | Y | | settings for aggregation optimizations |
_approx_cnt_distinct_gby_pushdown | String | choose | yes | SESSION | Y | Y | | perform group-by pushdown for approximate distinct count query |
_approx_cnt_distinct_optimization | Integer | 0 | yes | SESSION | Y | Y | | settings for approx_count_distinct optimizations |
_approx_percentile_optimization | Integer | 0 | yes | SESSION | Y | Y | | settings for approx_percentile optimization |
_auto_im_optimized_arithmetic | Boolean | FALSE | yes | SESSION | Y | N | | Enable Autonomous Inmemory Optimized Arithmetic |
_auto_im_vector_gby_opt | Boolean | FALSE | yes | SESSION | Y | N | | Enable Autonomous Vector Group By Optimization |
_autoptn_costing | Boolean | FALSE | yes | SESSION | N | N | | DBMS_AUTO_PARTITION is compiling query for cost estimates |
_backup_min_ct_unused_optim | Integer | 2097152 | yes | SESSION | Y | Y | | mimimun size in bytes of change tracking to apply unused space optimuzation |
_bctab_optimize_commit_performance | Boolean | FALSE | yes | SESSION | N | N | | optimize blockchain table commit performance |
_bloom_extent_size | Integer | 0 | yes | SESSION | Y | Y | | bloom filter extent size in bytes |
_bloom_filter_debug | Integer | 0 | yes | SESSION | Y | Y | | debug level for bloom filtering |
_bloom_filter_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enables or disables bloom filter |
_bloom_filter_multi_bit | Boolean | FALSE | yes | SESSION | Y | Y | | Multi-bit bloom filter |
_bloom_filter_ratio | Integer | 35 | yes | SESSION | Y | Y | | bloom filter filtering ratio |
_bloom_filter_setops_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Allow bloom filter to be pushed through set operations |
_bloom_filter_size | Integer | 0 | yes | SESSION | Y | Y | | bloom filter vector size (in KB) |
_bloom_folding_density | Integer | 16 | yes | SESSION | Y | Y | | bloom filter folding density lower bound |
_bloom_folding_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Enable folding of bloom filter |
_bloom_folding_min | Integer | 0 | yes | SESSION | Y | Y | | bloom filter folding size lower bound (in KB) |
_bloom_max_size | Integer | 262144 | yes | SESSION | Y | Y | | maximum bloom filter size (in KB) |
_bloom_max_wait_time | Integer | 50 | yes | SESSION | Y | Y | | bloom filter wait time upper bound (in ms) |
_bloom_minmax_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable or disable bloom min max filtering |
_bloom_predicate_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enables or disables bloom filter predicate pushdown |
_bloom_predicate_offload | Boolean | TRUE | yes | SESSION | Y | Y | | enables or disables bloom filter predicate offload to cells |
_bloom_pruning_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Enable partition pruning using bloom filtering |
_bloom_pruning_setops_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Allow bloom pruning to be pushed through set operations |
_bloom_pushing_folding_density | Integer | 4 | yes | SESSION | Y | Y | | bloom filter pushing folding density lower bound pushing to sage |
_bloom_pushing_max | Integer | 512 | yes | SESSION | Y | Y | | bloom filter pushing size upper bound (in KB) |
_bloom_pushing_total_max | Integer | 20971520 | yes | SESSION | Y | Y | | bloom filter combined pushing size upper bound (in KB) |
_bloom_rm_filter | Boolean | FALSE | yes | SESSION | Y | Y | | remove bloom predicate in favor of zonemap join pruning predicate |
_bloom_serial_filter | String | ON | yes | SESSION | Y | Y | | enable serial bloom filter on exadata |
_bloom_sm_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable bloom filter optimization using slave mapping |
_bloom_use_shared_pool | Boolean | FALSE | yes | SESSION | Y | Y | | use shared pool for bloom filter |
_bloom_wait_on_rac | Boolean | FALSE | yes | SESSION | Y | Y | | enables bloom filter (with hash hash distribution) wait on RAC |
_bt_mmv_query_rewrite_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | allow rewrites with multiple MVs and base tables |
_close_cached_open_cursors | Boolean | FALSE | yes | SESSION | N | N | | close cursors cached by PL/SQL at each commit |
_complex_view_merging | Boolean | TRUE | yes | SESSION | Y | Y | | enable complex view merging |
_cost_equality_semi_join | Boolean | TRUE | yes | SESSION | Y | Y | | enables costing of equality semi-join |
_cursor_bind_capture_area_size | Integer | 400 | yes | SYSTEM imm. | Y | Y | | maximum size of the cursor bind capture area |
_cursor_bind_capture_interval | Integer | 900 | yes | SYSTEM imm. | Y | Y | | interval (in seconds) between two bind capture for a cursor |
_cursor_cache_time | Integer | 900 | yes | SESSION | Y | N | | number of seconds a session cached cursor stay in cache. |
_cursor_db_buffers_pinned | Integer | 898 | yes | SESSION | Y | Y | | additional number of buffers a cursor can pin at once |
_cursor_diagnostic_node_agedout_count | Integer | 100 | yes | SYSTEM imm. | N | Y | | Number of cursor-sharing diagnostic nodes to retain before reuse |
_cursor_features_enabled | Integer | 8194 | yes | STATIC | Y | N | | Shared cursor features enabled bits. |
_cursor_obsolete_threshold | Integer | 8192 | yes | SESSION | N | N | | Number of cursors per parent before obsoletion. |
_cursor_plan_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable collection and display of cursor plans |
_cursor_plan_hash_version | Integer | 1 | yes | SESSION | Y | Y | | version of cursor plan hash value |
_cursor_plan_unparse_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enables/disables using unparse to build projection/predicates |
_cursor_reload_failure_threshold | Integer | 20 | yes | SESSION | Y | Y | | Number of failed reloads before marking cursor unusable |
_cursor_runtimeheap_memlimit | Big integer | 5242880 | yes | SESSION | Y | Y | | Shared cursor runtime heap memory limit |
_cursor_stats_enabled | Boolean | TRUE | yes | STATIC | Y | N | | Enable cursor stats |
_cursor_stats_purge_threshold | Integer | 0 | yes | SYSTEM imm. | N | Y | | Cursor stats purge threshold in minutes |
_db_file_optimizer_read_count | Integer | 8 | yes | SESSION | Y | Y | | multiblock read count for regular clients |
_db_noarch_disble_optim | Boolean | FALSE | yes | STATIC | N | N | | Image redo logging (NOARCHIVEMODE) |
_disable_cell_optimized_backups | Boolean | FALSE | yes | SESSION | Y | Y | | disable cell optimized backups |
_disable_chunkmv_optimize_exascale | Boolean | FALSE | yes | SESSION | Y | Y | | disable chunk move exascale optimization |
_disable_cursor_sharing | Boolean | FALSE | yes | SESSION | N | N | | disable cursor sharing |
_disable_dblink_optim | Boolean | TRUE | yes | SESSION | Y | Y | | disable intra CDB dblink optimizations |
_disable_sample_io_optim | Boolean | FALSE | yes | SESSION | Y | Y | | disable row sampling IO optimization |
_distinct_agg_optimization_gsets | String | CHOOSE | yes | SESSION | Y | Y | | Use Distinct Aggregate Optimization for Grouping Sets |
_distinct_view_unnesting | Boolean | FALSE | yes | SESSION | Y | Y | | enables unnesting of in subquery into distinct view |
_drop_table_optimization_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | reduce SGA memory use during drop of a partitioned table |
_dump_cursor_heap_sizes | Boolean | FALSE | yes | SESSION | Y | N | | dump comp/exec heap sizes to tryace file |
_enable_NUMA_optimization | Boolean | FALSE | yes | STATIC | N | N | | Enable NUMA specific optimizations |
_enable_query_rewrite_on_remote_objs | Boolean | TRUE | yes | SESSION | Y | Y | | mv rewrite on remote table/view |
_fast_cursor_reexecute | Boolean | FALSE | yes | SYSTEM def. | Y | Y | | use more memory in order to get faster execution |
_force_hash_join_spill | Boolean | FALSE | yes | SESSION | Y | Y | | force hash join to spill to disk |
_gby_hash_aggregation_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable group-by and aggregation using hash scheme |
_gby_onekey_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable use of one comparison of all group by keys |
_gby_vector_aggregation_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable group-by and aggregation using vector scheme |
_hash_join_enabled | Boolean | TRUE | yes | SESSION | Y | N | | enable/disable hash join |
_hcs_disable_av_gby_opt | Boolean | FALSE | yes | SESSION | Y | Y | | disable analytic view query group by optimization |
_hcs_disable_rm_like_withs_optz | Boolean | FALSE | yes | SESSION | Y | Y | | skip like WITH element removal optimization on generated SQL |
_hcs_disable_unnest | Boolean | FALSE | yes | SESSION | Y | Y | | disable unnest hint |
_hcs_disable_xform_gby | Boolean | FALSE | yes | SESSION | Y | Y | | disable transform group by |
_hcs_max_mdx_cursors | Integer | 100 | yes | SYSTEM imm. | Y | Y | | maximum number of MDX cursors |
_hpk_project_cost_weighting | Integer | 20 | yes | SESSION | Y | N | | hpk project cost weighting |
_index_join_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable the use of index joins |
_instance_recovery_bloom_filter_buffer_size | Integer | 4096 | yes | SYSTEM imm. | N | Y | | Bloom filter buffer size (in bytes) used during claim phase |
_instance_recovery_bloom_filter_fprate | String | 0.01 | yes | SYSTEM imm. | N | Y | | Allowable false positive percentage (0.001% to 100.00%) |
_instance_recovery_bloom_filter_size | Integer | 1048576 | no (was 10485760) | SYSTEM imm. | N | Y | | Bloom filter size (in bytes) used during claim phase |
_instance_recovery_bloom_size_ratio | String | 0.0003 | yes | SYSTEM imm. | N | Y | | Ratio that scales the size of the bloom filter based on the shared pool size. |
_kgl_max_hot_cursors_factor | Integer | 25 | yes | STATIC | Y | N | | Factor to compute max num of cursors that can be marked hot |
_kks_max_open_cursors_dup_limit | Integer | 5 | yes | SESSION | Y | Y | | number of duplicate cursors in open cursors that are acceptable |
_kks_open_cursors_dump_summary_threshold | Integer | 100 | yes | SESSION | Y | Y | | size to dump open cursors summary on max open cursors exceeded error |
_kks_reuse_ful_child_cursor | Integer | 3 | yes | SYSTEM imm. | Y | Y | | allow reuse of child cursor marked with FUL flag |
_kqr_optimistic_reads | Boolean | TRUE | yes | SESSION | Y | Y | | optimistic reading of row cache objects |
_like_with_bind_as_equality | Boolean | FALSE | yes | SESSION | Y | Y | | treat LIKE predicate with bind as an equality predicate |
_local_communication_costing_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable local communication costing when TRUE |
_log_max_optimize_threads | Integer | 128 | yes | STATIC | N | N | | maximum number of threads to which log scan optimization is applied |
_memoptimize_write_shrink_minsize | Boolean | TRUE | yes | SYSTEM imm. | N | Y | | shrinks Ingest Global Area size down to min size |
_memoptimize_writes_allow_fk | String | DISABLE | yes | STATIC | N | N | | enable both foreign key and memoptimize write for tables |
_memoptimize_writes_no_wait | Boolean | FALSE | yes | SESSION | N | N | | enable no wait conventional insert path for memoptimize write |
_memoptimize_xmem_pool_size | Big integer | 0 | yes | SYSTEM imm. | N | Y | | Size of MEMOPTIMIZE buffer pool for standard block size buffers on extended memory |
_mmv_query_rewrite_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | allow rewrites with multiple MVs and/or base tables |
_multi_transaction_optimization_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | reduce SGA memory use during create of a partitioned table |
_mv_refresh_costing | String | rule | yes | SESSION | N | N | | refresh decision based on cost or on rules |
_new_sort_cost_estimate | Boolean | TRUE | yes | SESSION | Y | Y | | enables the use of new cost estimate for sort |
_nlj_batching_ae_flag | Integer | 2 | yes | SESSION | Y | Y | | FAE flag type set after restoring to IO batching buffer |
_nlj_batching_enabled | Integer | 1 | yes | SESSION | Y | Y | | enable batching of the RHS IO in NLJ |
_nlj_batching_misses_enabled | Integer | 1 | yes | SESSION | Y | Y | | enable exceptions for buffer cache misses |
_olap_disable_loop_optimized | Boolean | FALSE | yes | SESSION | Y | Y | | Disable LOOP OPTIMIZED directive in OLAP_TABLE |
_optim_adjust_for_part_skews | Boolean | TRUE | yes | SESSION | Y | Y | | adjust stats for skews across partitions |
_optim_dict_stats_at_db_cr_upg | Boolean | TRUE | yes | SYSTEM imm. | N | Y | | enable/disable dictionary stats gathering at db create/upgrade |
_optim_enhance_nnull_detection | Boolean | TRUE | yes | SESSION | Y | Y | | TRUE to enable index [fast] full scan more often |
_optim_new_default_join_sel | Boolean | TRUE | yes | SESSION | Y | Y | | improves the way default equijoin selectivity are computed |
_optim_peek_user_binds | Boolean | TRUE | yes | SESSION | Y | Y | | enable peeking of user binds |
_optimize_dvconfig_cloudpdb | Boolean | FALSE | yes | SYSTEM imm. | N | Y | | Optimize Database Vault setup for cloud PDB |
_optimize_tbsquota_ddl | Boolean | TRUE | yes | SYSTEM imm. | Y | Y | | Optimize tablespace quota for user DDL |
_optimized_pdb_open_in_cloud | Boolean | FALSE | yes | SESSION | Y | Y | | Optimize PDB Open codepath |
_optimizefsio | String | | yes | SESSION | Y | Y | | Test env file i/o setting |
_optimizer_adaptive_cursor_sharing | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer adaptive cursor sharing |
_optimizer_adaptive_plan_control | Integer | 0 | yes | SESSION | Y | Y | | internal controls for adaptive plans |
_optimizer_adaptive_plans_continuous | Boolean | FALSE | yes | SESSION | Y | Y | | enable continuously adaptive plans |
_optimizer_adaptive_plans_iterative | Boolean | FALSE | yes | SESSION | Y | Y | | enable iterative adaptive plans |
_optimizer_adaptive_random_seed | Integer | 0 | yes | SESSION | Y | Y | | random seed for adaptive plans |
_optimizer_adjust_for_nulls | Boolean | TRUE | yes | SESSION | Y | Y | | adjust selectivity for null values |
_optimizer_ads_for_pq | Boolean | FALSE | yes | SESSION | Y | Y | | use ADS for parallel queries |
_optimizer_ads_max_table_count | Integer | 0 | yes | SESSION | Y | Y | | maximum number of tables in a join under ADS |
_optimizer_ads_result_cache_life | Integer | 3600 | yes | SESSION | Y | Y | | result cache shelf life for ADS queries |
_optimizer_ads_spd_cache_owner_limit | Integer | 64 | yes | SYSTEM imm. | Y | Y | | Maximum number of directives under an owner in SPD cache |
_optimizer_ads_time_limit | Integer | 0 | yes | SESSION | Y | Y | | maximum time limit (seconds) under ADS |
_optimizer_ads_use_partial_results | Boolean | TRUE | yes | SESSION | Y | Y | | Use partial results of ADS queries |
_optimizer_ads_use_result_cache | Boolean | TRUE | yes | SESSION | Y | Y | | use result cache for ADS queries |
_optimizer_ads_use_spd_cache | Boolean | TRUE | yes | SESSION | Y | Y | | use Sql Plan Directives for caching ADS queries |
_optimizer_aggr_groupby_elim | Boolean | TRUE | yes | SESSION | Y | Y | | group-by and aggregation elimination |
_optimizer_allow_all_access_paths | Boolean | TRUE | yes | SESSION | Y | Y | | allow all access paths |
_optimizer_ansi_join_lateral_enhance | Boolean | TRUE | yes | SESSION | Y | Y | | optimization of left/full ansi-joins and lateral views |
_optimizer_ansi_rearchitecture | Boolean | TRUE | yes | SESSION | Y | Y | | re-architecture of ANSI left, right, and full outer joins |
_optimizer_answering_query_using_stats | Boolean | FALSE | yes | SESSION | Y | Y | | enable statistics-based query transformation |
_optimizer_autostats_job | Boolean | TRUE | yes | SYSTEM imm. | Y | Y | | enable/disable auto stats collection job |
_optimizer_aw_join_push_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Enables AW Join Push optimization |
_optimizer_aw_stats_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Enables statistcs on AW olap_table table function |
_optimizer_band_join_aware | Boolean | TRUE | yes | SESSION | Y | Y | | enable the detection of band join by the optimizer |
_optimizer_batch_table_access_by_rowid | Boolean | TRUE | yes | SESSION | Y | Y | | enable table access by ROWID IO batching |
_optimizer_better_inlist_costing | String | ALL | yes | SESSION | Y | Y | | enable improved costing of index access using in-list(s) |
_optimizer_block_size | Integer | 8192 | yes | SESSION | Y | Y | | standard block size used by optimizer |
_optimizer_bushy_cost_factor | Integer | 100 | yes | SESSION | Y | Y | | cost factor for bushy join |
_optimizer_bushy_fact_dim_ratio | Integer | 20 | yes | SESSION | Y | Y | | bushy join dimension to fact ratio |
_optimizer_bushy_fact_min_size | Integer | 100000 | yes | SESSION | Y | Y | | minimumm fact size for bushy join |
_optimizer_bushy_join | String | off | yes | SESSION | Y | Y | | enables bushy join |
_optimizer_cache_stats | Boolean | FALSE | yes | SESSION | Y | Y | | cost with cache statistics |
_optimizer_cartesian_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer cartesian join enabled |
_optimizer_cbqt_factor | Integer | 50 | yes | SESSION | Y | Y | | cost factor for cost-based query transformation |
_optimizer_cbqt_no_size_restriction | Boolean | TRUE | yes | SESSION | Y | Y | | disable cost based transformation query size restriction |
_optimizer_cbqt_or_expansion | String | ON | yes | SESSION | Y | Y | | enables cost based OR expansion |
_optimizer_ceil_cost | Boolean | TRUE | yes | SESSION | Y | Y | | CEIL cost in CBO |
_optimizer_cluster_by_rowid | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable the cluster by rowid feature |
_optimizer_cluster_by_rowid_batch_size | Integer | 100 | yes | SESSION | Y | Y | | Sorting batch size for cluster by rowid feature |
_optimizer_cluster_by_rowid_batched | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable the cluster by rowid batching feature |
_optimizer_cluster_by_rowid_control | Integer | 129 | yes | SESSION | Y | Y | | internal control for cluster by rowid feature mode |
_optimizer_coalesce_subqueries | Boolean | TRUE | yes | SESSION | Y | Y | | consider coalescing of subqueries optimization |
_optimizer_compare_plans_control | Integer | 0 | yes | SESSION | Y | Y | | compare plans controls for testing |
_optimizer_complex_pred_selectivity | Boolean | TRUE | yes | SESSION | Y | Y | | enable selectivity estimation for builtin functions |
_optimizer_compute_index_stats | Boolean | TRUE | yes | SESSION | Y | Y | | force index stats collection on index creation/rebuild |
_optimizer_connect_by_cb_whr_only | Boolean | FALSE | yes | SESSION | Y | Y | | use cost-based transformation for whr clause in connect by |
_optimizer_connect_by_combine_sw | Boolean | TRUE | yes | SESSION | Y | Y | | combine no filtering connect by and start with |
_optimizer_connect_by_cost_based | Boolean | TRUE | yes | SESSION | Y | Y | | use cost-based transformation for connect by |
_optimizer_connect_by_elim_dups | Boolean | TRUE | yes | SESSION | Y | Y | | allow connect by to eliminate duplicates from input |
_optimizer_control_shard_qry_processing | Integer | 65280 | yes | SESSION | Y | Y | | control shard query processing |
_optimizer_correct_sq_selectivity | Boolean | TRUE | yes | SESSION | Y | Y | | force correct computation of subquery selectivity |
_optimizer_cost_based_transformation | String | LINEAR | yes | SESSION | Y | Y | | enables cost-based query transformation |
_optimizer_cost_filter_pred | Boolean | FALSE | yes | SESSION | Y | Y | | enables costing of filter predicates in IO cost model |
_optimizer_cost_hjsmj_multimatch | Boolean | TRUE | yes | SESSION | Y | Y | | add cost of generating result set when #rows per key > 1 |
_optimizer_cost_model | String | CHOOSE | yes | SESSION | Y | Y | | optimizer cost model |
_optimizer_cube_join_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable cube join |
_optimizer_db_blocks_buffers | Big integer | 0 | yes | SESSION | Y | Y | | optimizer value for _db_blocks_buffers |
_optimizer_degree | Integer | 0 | yes | SESSION | Y | Y | | force the optimizer to use the same degree of parallelism |
_optimizer_diag_stats | Boolean | TRUE | yes | SYSTEM imm. | Y | Y | | enable/disable populating stats diagnosis tables |
_optimizer_dim_subq_join_sel | Boolean | TRUE | yes | SESSION | Y | Y | | use join selectivity in choosing star transformation dimensions |
_optimizer_disable_strans_sanity_checks | Integer | 0 | yes | SESSION | Y | Y | | disable star transformation sanity checks |
_optimizer_distinct_agg_transform | Boolean | TRUE | yes | SESSION | Y | Y | | Transforms Distinct Aggregates to non-distinct aggregates |
_optimizer_distinct_elimination | Boolean | TRUE | yes | SESSION | Y | Y | | Eliminates redundant SELECT DISTNCT's |
_optimizer_distinct_placement | Boolean | TRUE | yes | SESSION | Y | Y | | consider distinct placement optimization |
_optimizer_dsdir_usage_control | Integer | 0 | yes | SESSION | Y | Y | | controls optimizer usage of dynamic sampling directives |
_optimizer_dyn_smp_blks | Integer | 32 | yes | SESSION | Y | Y | | number of blocks for optimizer dynamic sampling |
_optimizer_eliminate_filtering_join | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer filtering join elimination enabled |
_optimizer_eliminate_subquery | Boolean | TRUE | yes | SESSION | Y | Y | | consider elimination of subquery optimization |
_optimizer_enable_density_improvements | Boolean | TRUE | yes | SESSION | Y | Y | | use improved density computation for selectivity estimation |
_optimizer_enable_extended_stats | Boolean | TRUE | yes | SESSION | Y | Y | | use extended statistics for selectivity estimation |
_optimizer_enable_plsql_stats | Boolean | TRUE | yes | SESSION | Y | Y | | Use statistics of plsql functions |
_optimizer_enable_table_lookup_by_nl | Boolean | TRUE | yes | SESSION | Y | Y | | consider table lookup by nl transformation |
_optimizer_enhanced_filter_push | Boolean | TRUE | yes | SESSION | Y | Y | | push filters before trying cost-based query transformation |
_optimizer_enhanced_join_elimination | Boolean | TRUE | yes | SESSION | Y | Y | | Enhanced(12.2) join elimination |
_optimizer_exists_to_any_rewrite | Boolean | TRUE | yes | SESSION | Y | Y | | consider exists-to-any rewrite of subqueries |
_optimizer_extend_jppd_view_types | Boolean | TRUE | yes | SESSION | Y | Y | | join pred pushdown on group-by, distinct, semi-/anti-joined view |
_optimizer_extended_cursor_sharing | String | UDO | yes | SESSION | Y | Y | | optimizer extended cursor sharing |
_optimizer_extended_cursor_sharing_rel | String | SIMPLE | yes | SESSION | Y | Y | | optimizer extended cursor sharing for relational operators |
_optimizer_extended_stats_usage_control | Integer | 192 | yes | SESSION | Y | Y | | controls the optimizer usage of extended stats |
_optimizer_external_table_cache | Boolean | TRUE | yes | SESSION | Y | Y | | perform external table cache transform |
_optimizer_false_filter_pred_pullup | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer false predicate pull up transformation |
_optimizer_fast_access_pred_analysis | Boolean | TRUE | yes | SESSION | Y | Y | | use fast algorithm to traverse predicates for physical optimizer |
_optimizer_fast_pred_transitivity | Boolean | TRUE | yes | SESSION | Y | Y | | use fast algorithm to generate transitive predicates |
_optimizer_feedback_control | String | | yes | SESSION | Y | Y | | controls the optimizer feedback framework |
_optimizer_filter_pred_pullup | Boolean | TRUE | yes | SESSION | Y | Y | | use cost-based flter predicate pull up transformation |
_optimizer_filter_pushdown | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable filter predicate pushdown |
_optimizer_fkr_index_cost_bias | Integer | 10 | yes | SESSION | Y | Y | | Optimizer index bias over FTS/IFFS under first K rows mode |
_optimizer_force_CBQT | String | | yes | SESSION | Y | Y | | force CBQT transformation regardless of cost |
_optimizer_force_error_CBQT | String | | yes | SESSION | Y | Y | | force assert within a CBQT transformation |
_optimizer_force_error_hash | Big integer | | yes | SESSION | Y | Y | | force assert if hash of the error message equal to the parameter |
_optimizer_force_error_state | String | | yes | SESSION | Y | Y | | force assert in init phase, final phase or a candidate state |
_optimizer_free_transformation_heap | Boolean | TRUE | yes | SESSION | Y | Y | | free transformation subheap after each transformation |
_optimizer_full_outer_join_to_outer | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable full outer to left outer join conversion |
_optimizer_gather_feedback | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer gather feedback |
_optimizer_gather_stats_on_conventional_config | Integer | 0 | yes | SESSION | Y | Y | | settings for optimizer online stats gathering on conventional DML |
_optimizer_gather_stats_on_conventional_dml | Boolean | FALSE | yes | SESSION | Y | Y | | optimizer online stats gathering for conventional DML |
_optimizer_gather_stats_on_load | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable online statistics gathering |
_optimizer_gather_stats_on_load_all | Boolean | FALSE | yes | SESSION | Y | Y | | enable/disable online statistics gathering for nonempty segments |
_optimizer_gather_stats_on_load_hist | Boolean | FALSE | yes | SESSION | Y | Y | | enable/disable online histogram gathering for loads |
_optimizer_gather_stats_on_load_index | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable online index stats gathering for loads |
_optimizer_generate_ptf_implied_preds | Boolean | TRUE | yes | SESSION | Y | Y | | Generate implied predicates for PTF |
_optimizer_generate_transitive_pred | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer generate transitive predicates |
_optimizer_group_by_placement | Boolean | TRUE | yes | SESSION | Y | Y | | consider group-by placement optimization |
_optimizer_hll_entry | Integer | 4096 | yes | SESSION | Y | Y | | number of entries in hll hash table |
_optimizer_hybrid_fpwj_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable hybrid full partition-wise join when TRUE |
_optimizer_improve_selectivity | Boolean | TRUE | yes | SESSION | Y | Y | | improve table and partial overlap join selectivity computation |
_optimizer_inmemory_access_path | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer access path costing for in-memory |
_optimizer_inmemory_autodop | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer autoDOP costing for in-memory |
_optimizer_inmemory_bloom_filter | Boolean | TRUE | yes | SESSION | Y | Y | | controls serial bloom filter for in-memory tables |
_optimizer_inmemory_capture_stored_stats | Boolean | TRUE | yes | SYSTEM imm. | N | Y | | optimizer capture and store statistics for in-memory tables |
_optimizer_inmemory_cluster_aware_dop | Boolean | TRUE | yes | SESSION | Y | Y | | Affinitize DOP for inmemory objects |
_optimizer_inmemory_gen_pushable_preds | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer generate pushable predicates for in-memory |
_optimizer_inmemory_minmax_pruning | Boolean | TRUE | yes | SESSION | Y | Y | | controls use of min/max pruning for costing in-memory tables |
_optimizer_inmemory_pruning_ratio_rows | Integer | 100 | yes | SESSION | Y | Y | | in-memory pruning ratio for # rows (% of rows remaining after pruning) |
_optimizer_inmemory_quotient | Integer | 0 | yes | SESSION | Y | Y | | in-memory quotient (% of rows in in-memory format) |
_optimizer_inmemory_table_expansion | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer in-memory awareness for table expansion |
_optimizer_inmemory_use_stored_stats | String | AUTO | yes | SESSION | Y | Y | | optimizer use stored statistics for in-memory tables |
_optimizer_instance_count | Integer | 0 | yes | SESSION | Y | Y | | force the optimizer to use the specified number of instances |
_optimizer_interleave_jppd | Boolean | TRUE | yes | SESSION | Y | Y | | interleave join predicate pushdown during CBQT |
_optimizer_interleave_or_expansion | Boolean | TRUE | yes | SESSION | Y | Y | | interleave OR Expansion during CBQT |
_optimizer_invalidation_period | Integer | 18000 | yes | SYSTEM imm. | Y | Y | | time window for invalidation of cursors of analyzed objects |
_optimizer_ivf_iceberg_xt_consistent_read | Boolean | TRUE | yes | SESSION | Y | Y | | use consistent read with IVF on Iceberg external table |
_optimizer_ivf_iteration | Boolean | FALSE | yes | SESSION | Y | Y | | return all K rows using IVF multiple iteration |
_optimizer_ivf_postfilter_rows | Integer | 0 | yes | SESSION | Y | Y | | number of rows for IVF post-filter |
_optimizer_ivf_xt_cost_adj | Integer | 10 | yes | SESSION | Y | Y | | cost adjustment for external table scan with file pruning using key vector for IVF index |
_optimizer_ivf_xt_use_kv | Boolean | TRUE | yes | SESSION | Y | Y | | use key vector for IVF index on external table |
_optimizer_ivf_xt_use_temptbl | Boolean | TRUE | yes | SESSION | Y | Y | | use temporary table for IVF index on external table |
_optimizer_join_elimination_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer join elimination enabled |
_optimizer_join_factorization | Boolean | TRUE | yes | SESSION | Y | Y | | use join factorization transformation |
_optimizer_join_order_control | Integer | 3 | yes | SESSION | Y | Y | | controls the optimizer join order search algorithm |
_optimizer_join_sel_sanity_check | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable sanity check for multi-column join selectivity |
_optimizer_key_vector_aggr_factor | Integer | 75 | yes | SESSION | Y | Y | | the required aggregation between IJK and DGK |
_optimizer_key_vector_payload | Boolean | TRUE | yes | SESSION | Y | Y | | enables or disables dimension payloads in vector transform |
_optimizer_key_vector_payload_dim_aggs | Boolean | TRUE | yes | SESSION | Y | Y | | enables or disables dimension payloading of aggregates in VT |
_optimizer_key_vector_pruning_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enables or disables key vector partition pruning |
_optimizer_key_vector_use_max_size | Integer | 1048576 | yes | SESSION | Y | Y | | maximum key vector use size (in KB) |
_optimizer_max_permutations | Integer | 300 | yes | SESSION | Y | Y | | optimizer maximum join permutations per query block |
_optimizer_min_cache_blocks | Integer | 10 | yes | SESSION | Y | Y | | set minimum cached blocks |
_optimizer_mjc_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable merge join cartesian |
_optimizer_mode_force | Boolean | TRUE | yes | SESSION | Y | Y | | force setting of optimizer mode for user recursive SQL also |
_optimizer_multi_level_push_pred | Boolean | TRUE | yes | SESSION | Y | Y | | consider join-predicate pushdown that requires multi-level pushdown to base table |
_optimizer_multi_table_outerjoin | Boolean | TRUE | yes | SESSION | Y | Y | | allows multiple tables on the left of outerjoin |
_optimizer_multicol_join_elimination | Boolean | TRUE | yes | SESSION | Y | Y | | eliminate multi-column key based joins |
_optimizer_multiple_cenv | String | | yes | SESSION | Y | Y | | generate and run plans using several compilation environments |
_optimizer_multiple_cenv_report | String | result | yes | SESSION | Y | Y | | control what to report in trace file when run in multi-plan mode |
_optimizer_multiple_cenv_stmt | String | query | yes | SESSION | Y | Y | | control the types of statements that are run in multi-plan mode |
_optimizer_native_full_outer_join | String | FORCE | yes | SESSION | Y | Y | | execute full outer join using native implementaion |
_optimizer_nested_loop_join | String | on | yes | SESSION | Y | Y | | favor/unfavor nested loop join |
_optimizer_nested_rollup_for_gset | Integer | 100 | yes | SESSION | Y | Y | | number of groups above which we use nested rollup exec for gset |
_optimizer_new_join_card_computation | Boolean | TRUE | yes | SESSION | Y | Y | | compute join cardinality using non-rounded input values |
_optimizer_nlj_hj_adaptive_join | Boolean | TRUE | yes | SESSION | Y | Y | | allow adaptive NL Hash joins |
_optimizer_non_blocking_hard_parse | Boolean | TRUE | yes | SESSION | Y | Y | | enable non-blocking hard parse |
_optimizer_null_accepting_semijoin | Boolean | TRUE | yes | SESSION | Y | Y | | enables null-accepting semijoin |
_optimizer_null_aware_antijoin | Boolean | TRUE | yes | SESSION | Y | Y | | null-aware antijoin parameter |
_optimizer_or_expansion | String | DEPTH | yes | SESSION | Y | Y | | control or expansion approach used |
_optimizer_or_expansion_subheap | Boolean | TRUE | yes | SESSION | Y | Y | | Use subheap for optimizer or-expansion |
_optimizer_order_by_elimination_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Eliminates order bys from views before query transformation |
_optimizer_outer_join_to_inner | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable outer to inner join conversion |
_optimizer_outer_to_anti_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | Enable transformation of outer-join to anti-join if possible |
_optimizer_partial_join_eval | Boolean | TRUE | yes | SESSION | Y | Y | | partial join evaluation parameter |
_optimizer_percent_parallel | Integer | 101 | yes | SESSION | Y | Y | | optimizer percent parallel |
_optimizer_performance_feedback | String | OFF | yes | SESSION | Y | Y | | controls the performance feedback |
_optimizer_proc_rate_level | String | BASIC | yes | SESSION | Y | Y | | control the level of processing rates |
_optimizer_proc_rate_source | String | DEFAULT | yes | SESSION | Y | Y | | control the source of processing rates |
_optimizer_purge_stats_iteration_row_count | Integer | 10000 | yes | SESSION | Y | Y | | number of rows to be deleted at each iteration of the stats purging process |
_optimizer_push_down_distinct | Integer | 0 | yes | SESSION | Y | Y | | push down distinct from query block to table |
_optimizer_push_gby_into_union_all | Boolean | TRUE | yes | SESSION | Y | Y | | consider pushing down group-by into union-all branches |
_optimizer_push_pred_cost_based | Boolean | TRUE | yes | SESSION | Y | Y | | use cost-based query transformation for push pred optimization |
_optimizer_random_plan | Integer | 0 | yes | SESSION | Y | Y | | optimizer seed value for random plans |
_optimizer_reduce_groupby_key | Boolean | TRUE | yes | SESSION | Y | Y | | group-by key reduction |
_optimizer_reuse_cost_annotations | Boolean | TRUE | yes | SESSION | Y | Y | | reuse cost annotations during cost-based query transformation |
_optimizer_rownum_bind_default | Integer | 10 | yes | SESSION | Y | Y | | Default value to use for rownum bind |
_optimizer_rownum_pred_based_fkr | Boolean | TRUE | yes | SESSION | Y | Y | | enable the use of first K rows due to rownum predicate |
_optimizer_save_stats | Boolean | TRUE | yes | SYSTEM imm. | N | Y | | enable/disable saving old versions of optimizer stats |
_optimizer_search_limit | Integer | 5 | yes | SESSION | Y | Y | | optimizer search limit |
_optimizer_secure_view_merging | Boolean | TRUE | yes | SYSTEM imm. | Y | Y | | optimizer secure view merging and predicate pushdown/movearound |
_optimizer_self_induced_cache_cost | Boolean | FALSE | yes | SESSION | Y | Y | | account for self-induced caching |
_optimizer_skip_scan_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable index skip scan |
_optimizer_skip_scan_guess | Boolean | FALSE | yes | SESSION | Y | Y | | consider index skip scan for predicates with guessed selectivity |
_optimizer_sortmerge_join_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable sort-merge join method |
_optimizer_sortmerge_join_inequality | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable sort-merge join using inequality predicates |
_optimizer_squ_bottomup | Boolean | TRUE | yes | SESSION | Y | Y | | enables unnesting of subquery in a bottom-up manner |
_optimizer_star_tran_in_with_clause | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable star transformation in with clause queries |
_optimizer_star_trans_min_cost | Integer | 0 | yes | SESSION | Y | Y | | optimizer star transformation minimum cost |
_optimizer_star_trans_min_ratio | Integer | 0 | yes | SESSION | Y | Y | | optimizer star transformation minimum ratio |
_optimizer_starplan_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer star plan enabled |
_optimizer_stats_coll_max_buffer_size | Integer | 8 | yes | SESSION | Y | Y | | max buffer size of statistics collector rowsource |
_optimizer_stats_on_conventional_dml_sample_rate | Integer | 100 | yes | SESSION | Y | Y | | sampling rate for online stats gathering on conventional DML |
_optimizer_stats_on_conventional_upddel_threshold | Integer | 0 | yes | SESSION | Y | Y | | maximum threshold of updates + deletes to use real-time stats |
_optimizer_strans_adaptive_pruning | Boolean | TRUE | yes | SESSION | Y | Y | | allow adaptive pruning of star transformation bitmap trees |
_optimizer_subsume_vw_sq | String | ON | yes | SESSION | Y | Y | | consider subsumption of views or subqueries |
_optimizer_synopsis_min_size | Integer | 2 | yes | SESSION | Y | Y | | minimal synopsis size (kb) |
_optimizer_system_stats_usage | Boolean | TRUE | yes | SESSION | Y | Y | | system statistics usage |
_optimizer_table_expansion | Boolean | TRUE | yes | SESSION | Y | Y | | consider table expansion transformation |
_optimizer_trace | String | none | yes | SESSION | N | N | | optimizer trace parameter |
_optimizer_track_hint_usage | Boolean | TRUE | yes | SESSION | Y | Y | | enable tracking of optimizer hint usage |
_optimizer_transitivity_retain | Boolean | TRUE | yes | SESSION | Y | Y | | retain equi-join pred upon transitive equality pred generation |
_optimizer_try_st_before_jppd | Boolean | TRUE | yes | SESSION | Y | Y | | try Star Transformation before Join Predicate Push Down |
_optimizer_undo_changes | Boolean | FALSE | yes | SESSION | Y | Y | | undo changes to query optimizer |
_optimizer_undo_cost_change | String | 23.1.0 | yes | SESSION | Y | Y | | optimizer undo cost change |
_optimizer_union_all_gsets | Boolean | TRUE | yes | SESSION | Y | Y | | Use Union All Optimization for Grouping Sets |
_optimizer_unnest_all_subqueries | Boolean | TRUE | yes | SESSION | Y | Y | | enables unnesting of every type of subquery |
_optimizer_unnest_corr_set_subq | Boolean | TRUE | yes | SESSION | Y | Y | | Unnesting of correlated set subqueries (TRUE/FALSE) |
_optimizer_unnest_disjunctive_subq | Boolean | TRUE | yes | SESSION | Y | Y | | Unnesting of disjunctive subqueries (TRUE/FALSE) |
_optimizer_unnest_disjunctive_subq_outerjoin | Boolean | TRUE | yes | SESSION | Y | Y | | Unnesting of disjunctive subqueries using outerjoin (TRUE/FALSE) |
_optimizer_unnest_scalar_sq | Boolean | TRUE | yes | SESSION | Y | Y | | enables unnesting of of scalar subquery |
_optimizer_unnest_update_set_subq | String | on | yes | SESSION | Y | Y | | enables unnesting of subquery in set for update |
_optimizer_use_auto_indexes | String | AUTO | yes | SESSION | Y | Y | | Use Auto Index |
_optimizer_use_cbqt_star_transformation | Boolean | TRUE | yes | SESSION | Y | Y | | use rewritten star transformation using cbqt framework |
_optimizer_use_feedback | Boolean | TRUE | yes | SESSION | Y | Y | | optimizer use feedback |
_optimizer_use_feedback_for_join | Boolean | FALSE | yes | SESSION | Y | Y | | optimizer use feedback for join |
_optimizer_use_gtt_session_stats | Boolean | TRUE | yes | SESSION | Y | Y | | use GTT session private statistics |
_optimizer_use_histograms | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable the usage of histograms by the optimizer |
_optimizer_use_stats_models | Boolean | FALSE | yes | SESSION | Y | Y | | use optimizer statistics extrapolation models |
_optimizer_use_stats_on_conventional_config | Integer | 0 | yes | SESSION | Y | Y | | settings for optimizer usage of online stats on conventional DML |
_optimizer_use_stats_on_conventional_dml | Boolean | FALSE | yes | SESSION | Y | Y | | use optimizer statistics gathered for conventional DML |
_optimizer_use_subheap | Boolean | TRUE | yes | SESSION | Y | Y | | Enables physical optimizer subheap |
_optimizer_use_table_scanrate | String | HADOOP_ONLY | yes | SESSION | Y | Y | | Use Table Specific Scan Rate |
_optimizer_use_xt_rowid | Boolean | TRUE | yes | SESSION | Y | Y | | Use external table rowid |
_optimizer_vector_base_dim_fact_factor | Integer | 200 | yes | SESSION | Y | Y | | cost based vector transform base dimension to base fact ratio |
_optimizer_vector_cost_adj | Integer | 100 | yes | SESSION | Y | Y | | cost adjustment for vector aggregation processing estimates |
_optimizer_vector_fact_dim_ratio | Integer | 10 | yes | SESSION | Y | Y | | cost based vector transform dimension to fact ratio |
_optimizer_vector_fact_payload_ratio | Integer | 20 | yes | SESSION | Y | Y | | cost based vector transform payload dimension to fact ratio |
_optimizer_vector_index | String | ON | yes | SESSION | Y | Y | | consider transformation for vector index (HNSW and IVF |
_optimizer_vector_index_covering_columns | Boolean | TRUE | yes | SESSION | Y | Y | | use covering columns during vector index transformation |
_optimizer_vector_min_fact_rows | Integer | 10000000 | yes | SESSION | Y | Y | | min number of rows required for vector aggregation transform |
_optimizer_vector_transformation | Boolean | TRUE | yes | SESSION | Y | Y | | perform vector transform |
_optimizer_wc_filter_pushdown | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable with clause filter predicate pushdown |
_plsql_nvl_optimize | Boolean | FALSE | yes | SESSION | Y | Y | | PL/SQL NVL optimize |
_pre_rewrite_push_pred | Boolean | TRUE | yes | SESSION | Y | Y | | push predicates into views before rewrite |
_pred_push_cdb_view_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | predicate pushdown enabled for CDB views |
_push_join_predicate | Boolean | TRUE | yes | SESSION | Y | Y | | enable pushing join predicate inside a view |
_push_join_union_view | Boolean | TRUE | yes | SESSION | Y | Y | | enable pushing join predicate inside a union all view |
_push_join_union_view2 | Boolean | TRUE | yes | SESSION | Y | Y | | enable pushing join predicate inside a union view |
_query_cost_rewrite | Boolean | TRUE | yes | SESSION | Y | Y | | perform the cost based rewrite with materialized views |
_query_rewrite_1 | Boolean | TRUE | yes | SESSION | Y | Y | | perform query rewrite before&after or only before view merging |
_query_rewrite_2 | Boolean | TRUE | yes | SESSION | Y | Y | | perform query rewrite before&after or only after view merging |
_query_rewrite_drj | Boolean | FALSE | yes | SESSION | Y | Y | | mv rewrite and drop redundant joins |
_query_rewrite_expression | Boolean | TRUE | yes | SESSION | Y | Y | | rewrite with cannonical form for expressions |
_query_rewrite_extended_cursor_sharing | Boolean | TRUE | yes | SESSION | Y | Y | | allow extended cursor sharing for MV query rewrite |
_query_rewrite_fpc | Boolean | TRUE | yes | SESSION | Y | Y | | mv rewrite fresh partition containment |
_query_rewrite_fudge | Integer | 90 | yes | SESSION | Y | Y | | cost based query rewrite with MVs fudge factor |
_query_rewrite_jgmigrate | Boolean | TRUE | yes | SESSION | Y | Y | | mv rewrite with jg migration |
_query_rewrite_maxdisjunct | Integer | 257 | yes | SESSION | Y | Y | | query rewrite max disjuncts |
_query_rewrite_or_error | Boolean | FALSE | yes | SESSION | Y | Y | | allow query rewrite, if referenced tables are not dataless |
_query_rewrite_setopgrw_enable | Boolean | TRUE | yes | SESSION | Y | Y | | perform general rewrite using set operator summaries |
_query_rewrite_use_on_query_computation | Boolean | TRUE | yes | SESSION | Y | Y | | query rewrite use on query computation |
_query_rewrite_user_bind_peeking | Boolean | TRUE | yes | SESSION | Y | Y | | allow user bind peeking for MV query rewrite |
_query_rewrite_vop_cleanup | Boolean | TRUE | yes | SESSION | Y | Y | | prune frocol chain before rewrite after view-merging |
_read_optimized_table_lookup | Boolean | TRUE | yes | SESSION | Y | Y | | enables read-optimized table lookup |
_row_cache_cursors | Integer | 20 | yes | STATIC | N | N | | number of cached cursors for row cache management |
_skip_cursor_syspriv_rechecks | Boolean | FALSE | yes | SYSTEM imm. | Y | Y | | skip re-authorization of session cached cursors |
_smm_auto_cost_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | if TRUE, use the AUTO size policy cost functions |
_sort_elimination_cost_ratio | Integer | 0 | yes | SESSION | Y | Y | | cost ratio for sort eimination under first_rows mode |
_spr_push_pred_refspr | Boolean | TRUE | yes | SESSION | Y | Y | | push predicates through reference spreadsheet |
_sqlexec_cache_aware_hash_join_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | enable/disable cache aware hash join |
_sqlexec_distagg_optimization_settings | Integer | 0 | yes | SESSION | Y | Y | | settings for distinct aggregation optimizations |
_sqlexec_hash_join_uses_xmem | Boolean | FALSE | yes | SESSION | Y | Y | | enable/disable xmem PGA for hash join areas |
_subquery_pruning_cost_factor | Integer | 20 | yes | SESSION | Y | Y | | subquery pruning cost factor |
_table_scan_cost_plus_one | Boolean | TRUE | yes | SESSION | Y | Y | | bump estimated full table scan and index ffs cost by one |
_temp_undo_optimal_extents | Integer | 0 | yes | SESSION | Y | Y | | optimal number of extents for temp undo |
_truncate_optimization_enabled | Boolean | TRUE | yes | SESSION | Y | Y | | do truncate optimization if set to TRUE |
_unnest_subquery | Boolean | TRUE | yes | SESSION | Y | Y | | enables unnesting of complex subqueries |
_upgrade_optim | Boolean | TRUE | yes | SESSION | Y | Y | | Upgrade optimization enabled |
_windowfunc_optimization_settings | Integer | 0 | yes | SESSION | Y | Y | | settings for window function optimizations |
_xds_max_child_cursors | Integer | 100 | yes | SYSTEM imm. | N | Y | | Maximum number of XDS user-specific child cursors |
_xsolapi_optimize_suppression | Boolean | TRUE | yes | SESSION | Y | Y | | OLAP API optimizes suppressions? |
_xsolapi_sql_optimize | Boolean | TRUE | yes | SESSION | Y | Y | | OLAP API enable optimization
|
No comments:
Post a Comment