前回に続き、Oracle Database19cと21cの隠しパラメータを比較した結果のうち、21cで新規に登場した隠しパラメータについての纏め。
新規登場のパラメータ数が625個と非常に多いため、3回に分けて記載することとし、今回は_a～_fで始まる隠しパラメータを記載する。
※19cとの比較による新規隠しパラメータの抽出であるため、20cで新規登場したものも21cでの新規として記載する。隠しパラメータ数が多いため、PCでの閲覧推奨。
5.新規隠しパラメータ(_a* ～ _f*)
新規の隠しパラメータは625個存在し、_a* ～ _f*な隠しパラメータは220個存在した。
| パラメータ名 | デフォルト値 | ALTER SESSION | ALTER SYSTEM | パラメータ概要 |
|---|---|---|---|---|
| _actgrp_spawn_offload | TRUE | FALSE | FALSE | action group spawn offload |
| _adaptive_scalable_log_writer_evaluation_fraction | 100 | FALSE | IMMEDIATE | Serial/parallel log writer evaluation fraction (in 10000ths) |
| _adaptive_scalable_log_writer_evaluation_interval | 60 | FALSE | IMMEDIATE | Serial/parallel log writer evaluation interval (in seconds) |
| _age_block_batch_timeout_ms | 1000 | FALSE | IMMEDIATE | timeout before shipping out the batched age blockmessages in milliseconds |
| _alert_segment_size | 10 | FALSE | IMMEDIATE | Alert-log segment size in MBs (1024*1024) |
| _alert_segment_textfile | FALSE | FALSE | IMMEDIATE | Alert-log text-file also to be segmented |
| _alert_segments_max | 0 | FALSE | IMMEDIATE | Alert-log max segments to retain, 0 for unlimited |
| _allow_cross_version_chunk_move | FALSE | FALSE | IMMEDIATE | Oracle internal parameter |
| _allow_fallback_to_dbkey | FALSE | TRUE | IMMEDIATE | if TRUE, allow fallback to dbkey |
| _allow_privileged_session_dblink_conn | FALSE | TRUE | IMMEDIATE | Allow privileged session for dblink connection |
| _allow_synonym_for_credential | TRUE | FALSE | IMMEDIATE | Allow public/private synonym for scheduler credential |
| _allow_triggers_on_vpd_table | FALSE | FALSE | FALSE | Allow triggers on VPD protected table in DML |
| _allow_xdb_anonymous_logon | FALSE | TRUE | IMMEDIATE | Allow XDB anonymous logon |
| _allowed_pvf_owners | FALSE | IMMEDIATE | List of schemas allowed to own password verification function | |
| _aq_queue_global_service | NONE | FALSE | IMMEDIATE | AQ queue global service |
| _aq_tm_processes_dump_interval | 12 | FALSE | IMMEDIATE | Time(minutes) between consecutive Dumps in alert log |
| _aqsharded_cached_hint | 0 | FALSE | IMMEDIATE | sharded queue cached hint |
| _aqsharded_enq_fresh_ptn_reload | TRUE | FALSE | IMMEDIATE | start enqueueing to a fresh partition on reload |
| _aqsharded_lowmem_timeout | 1000 | FALSE | IMMEDIATE | sharded queue low mem timeout (in centiseconds) |
| _aqsharded_reload_tune | 0 | FALSE | IMMEDIATE | sharded queue tune reload behaviour |
| _asm_allow_appliance_offlineonline | FALSE | TRUE | IMMEDIATE | Allow OFFLINE/ONLINE DISK/FAILUREGROUP on ASM Appliances |
| _asm_buffer_overlap_tracer | FALSE | FALSE | IMMEDIATE | Enables kfioBufOverlapTracer |
| _asm_diskgroup_renew_timeout | 20 | FALSE | IMMEDIATE | timeout FENC will give former ASMB group owner to renew |
| _asm_dump_split_pw | 10 | TRUE | IMMEDIATE | Seconds to wait before requesting dump of split pending writes |
| _asm_enable_map_share | TRUE | FALSE | IMMEDIATE | Enable ASM extent map share |
| _asm_enable_vfreloc_on_rm | FALSE | FALSE | IMMEDIATE | Enable voting file relocation on rolling migration |
| _asm_frag_threshold | 50 | FALSE | IMMEDIATE | Percentage threshold before disk/diskgroup is deemed fragmented |
| _asm_hard_check | TRUE | TRUE | IMMEDIATE | H.A.R.D. check buffer before write operation |
| _asm_iosfailover_freq | 3 | FALSE | IMMEDIATE | Frequency limit after which db gives up on failing over to IOS |
| _asm_iosfailover_timeout | 5 | FALSE | IMMEDIATE | Time window within which db tries to failover to IOS |
| _asm_max_kfsg_free_heap_perc | 10 | FALSE | IMMEDIATE | Max percentage of SGA memory reserved for kfsga free heap |
| _asm_max_kfsg_free_heap_size | 524288000 | FALSE | IMMEDIATE | Max buffer size reserved for kfsga free heap |
| _asm_max_occupied | 90 | FALSE | IMMEDIATE | Maximum percentage of disk occupied to check for fragmentation |
| _asm_min_occupied | 50 | FALSE | IMMEDIATE | Minimum percentage of disk occupied to check for fragmentation |
| _asm_node_number | FALSE | IMMEDIATE | ASM node number | |
| _asm_offline_wait_timeout | 300 | TRUE | IMMEDIATE | Timeout for offline wait |
| _asm_ownerid_trace_timeout | 600 | FALSE | IMMEDIATE | ownerid tracing threshold in seconds |
| _asm_pst_rsinfo | 0 | FALSE | IMMEDIATE | file redundancies to consider during PST liveness checks |
| _asm_scrub_max_cod_wait | 5 | FALSE | IMMEDIATE | Number of minutes to delay scrub COD recovery |
| _asm_shared_pool_latch_timeout | 30 | FALSE | IMMEDIATE | seconds before terminating inst if ASMB is waiting for shared pool latch during shutdown |
| _asm_showpdb_asmtbl | FALSE | FALSE | IMMEDIATE | Allow asm table values to be shown in pdb |
| _asm_slow_client_timeout_percentage | 50 | TRUE | IMMEDIATE | Percentage of the write cancel timeout to detect slow client. |
| _asm_write_cancel_timeout_percentage | 30 | FALSE | IMMEDIATE | Percentage of the write timeout to wait before optional offline |
| _asm_xrov_cachelgio | 1 | FALSE | IMMEDIATE | ADVM cache large IO |
| _assert_single_current_buffer | FALSE | FALSE | IMMEDIATE | if TRUE, check and assert only one current buffer |
| _assm_auto_tracing_threshold | 10000 | TRUE | IMMEDIATE | ASSM threshold to start space search tracing |
| _auto_mv_enabled | FALSE | TRUE | IMMEDIATE | enable/disable Auto MV logic in the sql access advisor |
| _autoptn_costing | FALSE | TRUE | FALSE | DBMS_AUTO_PARTITION is compiling query for cost estimates |
| _autoptn_flags | 0 | TRUE | FALSE | DBMS_AUTO_PARTITION flags |
| _autoptn_translate_table_name | TRUE | FALSE | DBMS_AUTO_PARTITION table name translation | |
| _autoptn_workload_id | 0 | TRUE | FALSE | DBMS_AUTO_PARTITION workload id |
| _autosts_capture_control | 3 | TRUE | IMMEDIATE | internal controls for auto STS capture |
| _autosts_long_interval | 0 | FALSE | IMMEDIATE | Auto STS long flush interval |
| _autosts_retention_interval | 31 | FALSE | IMMEDIATE | Auto STS retention interval |
| _autosts_short_interval | 300 | FALSE | IMMEDIATE | Auto STS short flush interval |
| _aux_storage_size | 0 | FALSE | IMMEDIATE | Auxillary storage for PDB. |
| _awr_data_masking | FALSE | FALSE | IMMEDIATE | Enable/Disable AWR data masking functionality |
| _backup_interrupt_wait_time | 1000 | TRUE | IMMEDIATE | specifies interrupt wait time in centi seconds |
| _bct_public_dba_buffer_dynresize_delay | 3600 | TRUE | IMMEDIATE | control frequency of dynamic resizing of public dba buffers |
| _bigdata_offload_flag | FALSE | FALSE | IMMEDIATE | BigDataSQL offload flag |
| _block_change_tracking_file | FALSE | IMMEDIATE | file location for broker to reenable BCT | |
| _blockchain_forced_off | NOT_SET | TRUE | IMMEDIATE | force off blockchain |
| _blockchain_txn_apis_enabled | TRUE | FALSE | FALSE | If true, the txn layer blockchain API'S kick in |
| _blockchain_txn_test_lvl | 0 | FALSE | IMMEDIATE | blockchain txn test lvl |
| _blockchainHeapSize | 0 | TRUE | IMMEDIATE | Set the heap size in bytes for blockchain |
| _blockchainTracing | 0 | TRUE | IMMEDIATE | Set tracing for blockchain |
| _boc_mode | AUTO | FALSE | FALSE | Broadcast-on-commit mode |
| _boc_rdma_wait_time | 0 | FALSE | FALSE | BOC RDMA busy wait time (microseconds) |
| _buffer_requests_to_drain | 5 | FALSE | IMMEDIATE | Buffer for requests to drain before planned failover |
| _bug30932330_forceopen_bind_undotbs | FALSE | TRUE | IMMEDIATE | one-hundred-and-forty-fifth spare parameter - boolean |
| _bug31789178_asm_quorum_hb | FALSE | TRUE | IMMEDIATE | Allow Quorum Disk Heartbeat |
| _bug31828999_lm_nodrm_service_pct | 95 | TRUE | IMMEDIATE | minimum nonsingleton service access percentage to disable drm |
| _bug31918168_keusp_stream_batch_size | DEFAULT | TRUE | IMMEDIATE | Number of KEUSP buffers to flush in a stream batch |
| _bug31990919_keusp_max_num_alloc_buf | DEFAULT | TRUE | IMMEDIATE | Maximum number of KEUSP buffers in shared memory |
| _bug32093558_j0_deq_maxwait_time | 0 | TRUE | IMMEDIATE | eighth spare parameter - integer |
| _bug32093558_srvntfn_max_job_time | 180 | TRUE | IMMEDIATE | seventh spare parameter - integer |
| _bug32171622_asm_reloc_restart_timeout | 900 | FALSE | IMMEDIATE | csecs before signaling ORA-15424 when waiting for orphans |
| _bug32183142_hang_fast_track_progressing_sessions | FALSE | TRUE | IMMEDIATE | Hang Management fast-track progressing sessions enabled |
| _bug32498459_max_small_page_sga_size | 0 | FALSE | IMMEDIATE | Maximum SGA size with small pages |
| _bug32533019_DON_for_update_enabled | FALSE | FALSE | IMMEDIATE | Default on null for update feature enabled |
| _bypass_sensitive_context | FALSE | FALSE | IMMEDIATE | bypass sensitive handling for specific SYS_CONTEXT() parameters |
| _cache_fusion_pipelined_updates_enable | TRUE | FALSE | IMMEDIATE | Enable smart fusion block transfer |
| _cdb_init_batch_size | 100 | TRUE | IMMEDIATE | Batch size for reading pdb info during CDB mount |
| _cdb_svlt_use_tcps | FALSE | FALSE | IMMEDIATE | Use TCPS for CDB Servlet |
| _cell_metadata_compression | AUTO | TRUE | IMMEDIATE | Cell metadata compression strategy |
| _cell_offload_vector_groupby_external | TRUE | TRUE | IMMEDIATE | enable cell offload of vector group by with external tables |
| _cgs_clscevents_dumpinterval | 600 | FALSE | IMMEDIATE | cgs clsce events statistics dump interval in seconds |
| _cgs_publish_netinfo_collect_event_chmjf | TRUE | FALSE | IMMEDIATE | enable cgs publish collect_netinfo event to event stream for CHM with CHM'S JASON format |
| _cgs_publish_netinfo_collect_event_chmjf_batchsz | 0 | FALSE | IMMEDIATE | batch size of cgs events publishing to CHM in json format via clsce event stream |
| _cgs_query_net_interface | SCLSI | FALSE | FALSE | api to query network interface |
| _cloud_mandatory_profile_setup | FALSE | FALSE | IMMEDIATE | Mandatory Profile Setup for Multitenant Cloud Environment |
| _cloudsql_offload_enabled | FALSE | FALSE | IMMEDIATE | enable CloudSQL cell offload support |
| _cluster_database_instances | FALSE | FALSE | number of instances to use for sizing cluster db SGA structures | |
| _connstr_test_param | 0 | TRUE | FALSE | connect string workload behavior spare param |
| _consensus_follower_election_timeout | 12000 | TRUE | IMMEDIATE | consensus follower's election timeout |
| _consensus_leader_heartbeat_interval | 6000 | TRUE | IMMEDIATE | consensus leader's heartbeat interval |
| _consensus_leader_maximum_heartbeats | TRUE | IMMEDIATE | consensus leader's maximum heartbeats | |
| _consensus_queue_maximum_elements | 10 | TRUE | IMMEDIATE | consensus queue maximum elements |
| _consensus_slaves_maximum_count | 5 | TRUE | IMMEDIATE | consensus slaves maximum count |
| _cp_del_free_sess | TRUE | FALSE | IMMEDIATE | connection pool: delete free sessions when at PDB limit |
| _cp_del_free_sess_limit_secs | 1 | FALSE | IMMEDIATE | connection pool: delete free sessions time limit (in seconds) |
| _cputime_limit_parallel_fptr | 60 | FALSE | IMMEDIATE | CPU-time limit for for parallel first-pass recovery |
| _create_pdb_disable_mirror_reads | FALSE | TRUE | IMMEDIATE | Disable mirror reads during create pdb |
| _create_pdb_flashback_barrier | FALSE | TRUE | IMMEDIATE | force flashback barrier for create pdb |
| _cross_con_remove_pushed_preds | FALSE | TRUE | IMMEDIATE | remove pushed predicates from query fetching across containers |
| _ctas_numfrags_hint | 0 | TRUE | IMMEDIATE | Hint for number of partition fragments to be loaded in a CTAS |
| _ctex_fk_copy_mode | 1 | TRUE | IMMEDIATE | Create table for exchange Copy mode for referential constraints |
| _datapump_bypass_tstz_check | FALSE | FALSE | IMMEDIATE | Bypass Data Pump TSTZ version checking during import. |
| _datapump_hide_cdb_warning | FALSE | FALSE | IMMEDIATE | Hide Data Pump warning for CDB$ROOT and PDB$SEED |
| _db_cache_advice_size_submultiple | 10 | FALSE | FALSE | cache advisory size submultiple |
| _db_cache_pmem_confidence_try | 0 | FALSE | IMMEDIATE | DB Cache PMEM buffer promote attempts for greater confidence |
| _db_cache_pmem_promotion_touch_rate_reset_interval | 300 | FALSE | IMMEDIATE | DB Cache PMEM promotion touch rate reset interval in sec |
| _db_cache_pmem_promotion_touch_rate_threshold_time | 30 | FALSE | IMMEDIATE | DB Cache PMEM promotion touch rate threshold time in sec |
| _db_cache_pmem_touch_rate_compare_per | 95 | FALSE | IMMEDIATE | DB Cache PMEM buffer touch rate additive percentage when comparingagainst dram touch rate |
| _db_cache_pmemp_len | 10000 | FALSE | IMMEDIATE | DB Cache PMEM promotion list max length |
| _db_cache_xmem_promotion_algo_chosen | 38 | FALSE | IMMEDIATE | DB Cache Xmem/Pmem promotion algo |
| _db_nvm_promotion_deferred_tchcnt | 195 | FALSE | FALSE | touch count threshold which allows deferred background based nvm buffer promotion |
| _db_pmem_auto_resize_interval | 10 | FALSE | IMMEDIATE | PMEM auto resize interval in minutes |
| _db_pmem_direct_map_size | 0 | FALSE | IMMEDIATE | Size of direct mappable PMEM buffer cache |
| _db_replay_security_config | FALSE | IMMEDIATE | Database Replay Security Configuration | |
| _dbnest_resource_opts | 0 | FALSE | FALSE | dbNest - resource options |
| _dbnest_skip_fed_root | TRUE | FALSE | FALSE | Fed root is skipped so CDB nest is root of all pdbs |
| _dbopen_breakpoint | none | FALSE | IMMEDIATE | ALTER DATABASE OPEN codepath breakpoint |
| _dbreplay_mpk_key | FALSE | IMMEDIATE | Database Replay Package Key | |
| _ddlapply_enable | FALSE | FALSE | FALSE | DDL VIA APPLY Enable |
| _default_ini_trans_index | 0 | TRUE | IMMEDIATE | Default value of INI_TRANS enforced by DWCS lockdown for indexes |
| _default_ini_trans_table | 0 | TRUE | IMMEDIATE | Default value of INI_TRANS enforced by DWCS lockdown for tables |
| _default_oracle_fs_type | ofs | FALSE | IMMEDIATE | default file system type for an oracle file system |
| _default_service | TRUE | FALSE | FALSE | Run default service |
| _defer_rcv_pdb_attach | TRUE | FALSE | IMMEDIATE | Defer PDB domain attach in instance recovery |
| _defer_rewrap_controlfile_key_history | FALSE | FALSE | IMMEDIATE | if TRUE, defer rewrap control file TS keys under next PDB open |
| _dgb_dgpdb_appst | NONE | FALSE | IMMEDIATE | DGPDBs with apply state off |
| _dgpdb_file_name_convert | FALSE | IMMEDIATE | datafile name convert patterns and strings for per PDB standby | |
| _dgpdb_file_name_convert | FALSE | IMMEDIATE | datafile name convert patterns and strings for per PDB standby | |
| _dgpdb_standby_controlfile_name | dgpdb_temp_copy_cf_%u_stby_%u_%u.cf | FALSE | FALSE | a name template with three %u's for DGPDB standby controlfile |
| _direct_io_via_mapped_pmem | TRUE | TRUE | IMMEDIATE | if TRUE, direct path I/O will attempt to memory map files on PMEM |
| _disable_block_corruption_track | FALSE | TRUE | IMMEDIATE | disable block corruption tracking |
| _disable_foreign_scn_adjust | FALSE | TRUE | IMMEDIATE | Disable foreign SCN adjustment |
| _disable_ilm_internal | FALSE | FALSE | IMMEDIATE | Force disable internal ilm stats and drop ilm segment |
| _disable_last_successful_login_time | FALSE | FALSE | IMMEDIATE | Disable writing Last Successful Login Time to USER$ |
| _disable_mandatory_profile_onclone | FALSE | FALSE | IMMEDIATE | Disable Mandatory Profile check on clone of a PDB |
| _disable_marking_noops | FALSE | TRUE | IMMEDIATE | Don't mark any captured statements as no-ops. |
| _disable_orphan_pdb_recovery | FALSE | FALSE | IMMEDIATE | Disable PDB PITR/FB to orphan PDB incarnation |
| _disable_pdb_space_check | FALSE | TRUE | FALSE | Disable pdb storage usage check in the session |
| _disable_sga_filedel | FALSE | FALSE | FALSE | disable deletion of files used for SGA |
| _dmm_ser_test | 0 | TRUE | IMMEDIATE | Stress testing for serialized models |
| _dmm_xgboost_max_memory | 1000000000 | TRUE | IMMEDIATE | xgboost maximum memory |
| _dp_force_length_semantics | NONE | FALSE | IMMEDIATE | Force nls length semantics |
| _dynamic_hash_bucket_array | TRUE | FALSE | IMMEDIATE | dynamic hash bucket array |
| _dynamic_processes_force_timeout | 6 | FALSE | IMMEDIATE | dynamic process force timeout |
| _dynamic_processes_max_oom_timeout | 300 | FALSE | IMMEDIATE | dynamic process max timeout for out of memory |
| _dynamic_processes_wait_timeout | 100 | FALSE | IMMEDIATE | dynamic process wait timeout for new process |
| _eighteenth_spare_pdb_parameter | TRUE | IMMEDIATE | eighteenth spare pdb parameter - integer | |
| _eighth_spare_pdb_parameter | TRUE | IMMEDIATE | eighth spare pdb parameter - integer | |
| _eleventh_spare_pdb_parameter | TRUE | IMMEDIATE | eleventh spare pdb parameter - integer | |
| _enable_block_level_transaction_recovery | TRUE | FALSE | DEFERRED | enable block level recovery |
| _enable_bug_29838374 | 0 | TRUE | IMMEDIATE | enable/disable bug fix 29838374 |
| _enable_cdb_all_sync | FALSE | TRUE | FALSE | Is CDB-wide ALL sync enabled |
| _enable_dbwr_parallel_invalidations | TRUE | FALSE | IMMEDIATE | if TRUE, enables flush and invalidate by DBWRs |
| _enable_dynamic_processes | FALSE | FALSE | FALSE | dynamic process SOs |
| _enable_fsdirect_odmlib | TRUE | FALSE | FALSE | enable or disable FsDirect static ODM library |
| _enable_fsdirect_pin | TRUE | FALSE | IMMEDIATE | enable direct pin of FsDirect blocks |
| _enable_fsdirect_rac | FALSE | FALSE | IMMEDIATE | enable FsDirect in RAC |
| _enable_gsm_listener_networks | TRUE | FALSE | IMMEDIATE | gsm listener in listener networks |
| _enable_ignorable_error_capture | FALSE | TRUE | IMMEDIATE | Capture statement if error is ignorable |
| _enable_increase_lms_process | TRUE | FALSE | IMMEDIATE | set to true to allow _increase_lms_process changes |
| _enable_load_from_clone | TRUE | FALSE | IMMEDIATE | Is load from a Root Clone allowed |
| _enable_log_memory_protection_key | TRUE | FALSE | FALSE | enable memory protection keys (log) |
| _enable_memory_protection_keys | FALSE | FALSE | FALSE | Enable memory protection keys usage |
| _enable_mle | TRUE | FALSE | IMMEDIATE | enable MLE |
| _enable_pdb_skiplist_recovery | TRUE | TRUE | IMMEDIATE | Enable pdb skip list setup during media recovery. |
| _enable_pdb_skiplist_redogen | TRUE | FALSE | IMMEDIATE | Enable pdb skip list setup during redo generation. |
| _enable_per_container_acl | FALSE | FALSE | IMMEDIATE | Enable Per Container ACL |
| _enable_perpdb_suplog | FALSE | FALSE | IMMEDIATE | per pdb supplemental logging |
| _enable_pmem_direct_cache | TRUE | FALSE | IMMEDIATE | if TRUE, enable PMEM direct mapped buffers |
| _enable_pmem_exchange | TRUE | FALSE | IMMEDIATE | if TRUE, enable PMEM exchange during promotion |
| _enable_pmem_prefetch | FALSE | FALSE | IMMEDIATE | if TRUE, enable prefecting from PMEM |
| _enable_ptime_update_for_sys | FALSE | FALSE | FALSE | Enable/Disable update of user$ for sys |
| _enable_tenant_id_check | FALSE | FALSE | IMMEDIATE | Enable Tenant Id check for database link |
| _enable_tenant_id_transfer | FALSE | FALSE | IMMEDIATE | Enable Tenant Id transfer |
| _enable_unified_memory | FALSE | FALSE | FALSE | Enable use of unified PGA pool |
| _endprot_stack_segments | FALSE | FALSE | FALSE | overrun protection for kgh stack segments |
| _enforce_minimum_password_rollover_time | TRUE | FALSE | FALSE | Enforce minimum PASSWORD_ROLLOVER_TIME of one hour |
| _enqueue_wall_clock_time | FALSE | FALSE | IMMEDIATE | if TRUE, use KSUFTIME timer |
| _exa_pmemlog_threshold_usec | 100 | FALSE | IMMEDIATE | maximum i/o time (usecs) for enabled Exadata PMEMLog |
| _failover_svrcsum | FALSE | TRUE | IMMEDIATE | enable server checksum to optimize failover |
| _fb_log_max_rereads | 100 | FALSE | IMMEDIATE | Maximum number of rereads after reading a corrupt flashback block |
| _fb_recovery_slave_count | 0 | FALSE | IMMEDIATE | Number of recovery slaves to be used by the FLASHBACK DATABASE |
| _fbda_adv_gbl_bscn_bcast_interval | 0 | FALSE | IMMEDIATE | flashback archiver broadcast interval to advance global barrier SCN |
| _ffs_in_range_scan_threshold | 50 | TRUE | IMMEDIATE | threshold of min percentage of block read to use ffs in rs |
| _fifteenth_spare_pdb_parameter | TRUE | IMMEDIATE | fifteenth spare pdb parameter - integer | |
| _fifth_spare_pdb_parameter | TRUE | IMMEDIATE | fifth spare pdb parameter - integer | |
| _fiftieth_spare_pdb_parameter | TRUE | IMMEDIATE | fiftieth spare pdb parameter - string list | |
| _fifty-eighth_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-eighth spare pdb parameter - boolean |
| _fifty-fifth_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-fifth spare pdb parameter - boolean |
| _fifty-fourth_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-fourth spare pdb parameter - boolean |
| _fifty-ninth_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-ninth spare pdb parameter - boolean |
| _fifty-seventh_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-seventh spare pdb parameter - boolean |
| _fifty-sixth_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-sixth spare pdb parameter - boolean |
| _fifty-third_spare_pdb_parameter | TRUE | TRUE | IMMEDIATE | fifty-third spare pdb parameter - boolean |
| _first_spare_pdb_parameter | TRUE | IMMEDIATE | first spare pdb parameter - integer | |
| _fixup_all_apps | FALSE | TRUE | FALSE | Callback to fix up replay state of all applications |
| _fixup_app_pdb_status_in_root | TRUE | IMMEDIATE | application name whose PDB application status should be fixed up | |
| _fixup_cdb_apps | FALSE | TRUE | FALSE | Callback to fix up replay state of CDB-wide applications |
| _force_dax_io_err | 0 | FALSE | IMMEDIATE | Force I/O error on online/standby redo log |
| _force_pmem_direct_mapped_cache_scan | TRUE | TRUE | IMMEDIATE | if TRUE, force PMEM mapped direct path scan to cache path scan |
| _forced_endian_type | UNKNOWN | FALSE | IMMEDIATE | Forced endian type of data dictionary |
| _fortieth_spare_pdb_parameter | TRUE | IMMEDIATE | fortieth spare pdb parameter - string | |
| _forty-eighth_spare_pdb_parameter | TRUE | IMMEDIATE | forty-eighth spare pdb parameter - string list | |
| _forty-fifth_spare_pdb_parameter | TRUE | IMMEDIATE | forty-fifth spare pdb parameter - string list | |
| _forty-first_spare_pdb_parameter | TRUE | IMMEDIATE | forty-first spare pdb parameter - string list | |
| _forty-fourth_spare_pdb_parameter | TRUE | IMMEDIATE | forty-fourth spare pdb parameter - string list | |
| _forty-ninth_spare_pdb_parameter | TRUE | IMMEDIATE | forty-ninth spare pdb parameter - string list | |
| _forty-second_spare_pdb_parameter | TRUE | IMMEDIATE | forty-second spare pdb parameter - string list | |
| _forty-seventh_spare_pdb_parameter | TRUE | IMMEDIATE | forty-seventh spare pdb parameter - string list | |
| _forty-sixth_spare_pdb_parameter | TRUE | IMMEDIATE | forty-sixth spare pdb parameter - string list | |
| _forty-third_spare_pdb_parameter | TRUE | IMMEDIATE | forty-third spare pdb parameter - string list | |
| _fourteenth_spare_pdb_parameter | TRUE | IMMEDIATE | fourteenth spare pdb parameter - integer | |
| _fourth_spare_pdb_parameter | TRUE | IMMEDIATE | fourth spare pdb parameter - integer | |
| _fsdirect_fast_file_create | TRUE | TRUE | IMMEDIATE | Allow optimized file creation path for FsDirects |
_g以降から始まる隠しパラメータについては、次回。
