【12c新特性】12c中新增的V$动态视图

【12c新特性】12c中新增的V$动态视图:

select A.view_name from v$fixed_view_definition A where A.view_name not in (select B.view_name from v$fixed_view_definition@11gR2 B)
and view_name like ‘GV%’ order by 1;

 

GV$AQ_BACKGROUND_COORDINATOR
GV$AQ_BMAP_NONDUR_SUBSCRIBERS
GV$AQ_CROSS_INSTANCE_JOBS
GV$AQ_JOB_COORDINATOR
GV$AQ_MESSAGE_CACHE
GV$AQ_MSGBM
GV$AQ_NONDUR_REGISTRATIONS
GV$AQ_NONDUR_SUBSCRIBER
GV$AQ_NONDUR_SUBSCRIBER_LWM
GV$AQ_NOTIFICATION_CLIENTS
GV$AQ_SERVER_POOL
GV$AQ_SUBSCRIBER_LOAD
GV$ASM_ACFSREPL
GV$ASM_ACFSREPLTAG
GV$ASM_ACFSTAG
GV$ASM_ACFS_SEC_ADMIN
GV$ASM_ACFS_SEC_CMDRULE
GV$ASM_ACFS_SEC_REALM
GV$ASM_ACFS_SEC_REALM_FILTER
GV$ASM_ACFS_SEC_REALM_GROUP
GV$ASM_ACFS_SEC_REALM_USER
GV$ASM_ACFS_SEC_RULE
GV$ASM_ACFS_SEC_RULESET
GV$ASM_ACFS_SEC_RULESET_RULE
GV$ASM_AUDIT_CLEANUP_JOBS
GV$ASM_AUDIT_CLEAN_EVENTS
GV$ASM_AUDIT_CONFIG_PARAMS
GV$ASM_AUDIT_LAST_ARCH_TS
GV$ASM_ESTIMATE
GV$BACKUP_NONLOGGED
GV$BTS_STAT
GV$BT_SCAN_CACHE
GV$BT_SCAN_OBJ_TEMPS
GV$CACHE
GV$CACHE_LOCK
GV$CACHE_TRANSFER
GV$CELL_OFL_THREAD_HISTORY
GV$CHANNEL_WAITS
GV$CLIENT_SECRETS
GV$CLONEDFILE
GV$CONTAINERS
GV$CON_SYSSTAT
GV$CON_SYSTEM_EVENT
GV$CON_SYSTEM_WAIT_CLASS
GV$CON_SYS_TIME_MODEL
GV$COPY_NONLOGGED
GV$DEAD_CLEANUP
GV$DG_BROKER_CONFIG
GV$EDITIONABLE_TYPES
GV$ENCRYPTION_KEYS
GV$FALSE_PING
GV$FLASHFILESTAT
GV$GES_DEADLOCKS
GV$GES_DEADLOCK_SESSIONS
GV$GG_APPLY_COORDINATOR
GV$GG_APPLY_READER
GV$GG_APPLY_RECEIVER
GV$GG_APPLY_SERVER
GV$GOLDENGATE_CAPABILITIES
GV$GOLDENGATE_CAPTURE
GV$GOLDENGATE_MESSAGE_TRACKING
GV$GOLDENGATE_TABLE_STATS
GV$GOLDENGATE_TRANSACTION
GV$HEAT_MAP_SEGMENT
GV$INSTANCE_PING
GV$IOS_CLIENT
GV$IO_OUTLIER
GV$KERNEL_IO_OUTLIER
GV$KSFQP
GV$LGWRIO_OUTLIER
GV$MAPPED_SQL
GV$NONLOGGED_BLOCK
GV$OFSMOUNT
GV$OFS_STATS
GV$OPTIMIZER_PROCESSING_RATE
GV$PATCHES
GV$PDBS
GV$PDB_INCARNATION
GV$PING
GV$PX_PROCESS_TRACE
GV$REPLAY_CONTEXT
GV$REPLAY_CONTEXT_LOB
GV$REPLAY_CONTEXT_SEQUENCE
GV$REPLAY_CONTEXT_SYSDATE
GV$REPLAY_CONTEXT_SYSGUID
GV$REPLAY_CONTEXT_SYSTIMESTAMP
GV$RO_USER_ACCOUNT
GV$RT_ADDM_CONTROL
GV$SCHEDULER_INMEM_MDINFO
GV$SCHEDULER_INMEM_RTINFO
GV$SESSIONS_COUNT
GV$SQL_DIAG_REPOSITORY
GV$SQL_DIAG_REPOSITORY_REASON
GV$SQL_MONITOR_SESSTAT
GV$SQL_MONITOR_STATNAME
GV$SQL_REOPTIMIZATION_HINTS
GV$SYS_REPORT_REQUESTS
GV$SYS_REPORT_STATS
GV$TEMPUNDOSTAT
GV$TSDP_SUPPORTED_FEATURE
GV$UNIFIED_AUDIT_TRAIL
GV$XSTREAM_APPLY_COORDINATOR
GV$XSTREAM_APPLY_READER
GV$XSTREAM_APPLY_RECEIVER
GV$XSTREAM_APPLY_SERVER
GV$XSTREAM_CAPTURE
GV$XSTREAM_MESSAGE_TRACKING
GV$XSTREAM_TRANSACTION
GV$XS_SESSIONS
GV$XS_SESSION_NS_ATTRIBUTE
GV$XS_SESSION_ROLE

 

 

【12c新特性】多LGWR进程SCALABLE LGWR “_use_single_log_writer”

SCALABLE LGWR是12cR1中引入的一个令人激动的特性, 这是由于在OLTP环境中LGWR写日志往往成为系统的主要性能瓶颈, 如果LGWR进程能像DBWR(DBW0~DBWn)那样多进程写出redo到LOGFILE那么就可能大幅释放OLTP的并发能力,增长Transcation系统的单位时间事务处理能力。

 

在12cR1 中真正用SCALABLE LGWR实现了这个目的, 也可以俗称为多LGWR进程。

 

 

         select * from opt_12cR1 where name like '%log%'
_use_single_log_writer	ADAPTIVE	Use a single process for redo log writing
_max_outstanding_log_writes	2	Maximum number of outstanding redo log writes

 

SCALABLE LGWR主要受到隐藏参数_use_single_log_writer的控制,  该参数默认值为ADAPTIVE 。

 

该参数主要有三个可选值 true, false, adaptive, 默认值为ADAPTIVE。

  • 对于ADAPTIVE 和False 如果CPU个数大于一个则会有多个lg0n进程
  • 对于true 则不会生成多个lg0n进程,而如同12.1之前那样仅有单个LGWR

 

 

 

SQL> show parameter _use_single_log_writer

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
_use_single_log_writer               string      ADAPTIVE

www.askmaclean.com

[oracle@maclean1 ~]$ ps -ef|grep lg
grid      4344     1  0 08:07 ?        00:00:00 asm_lgwr_+ASM1
oracle   12628     1  0 08:48 ?        00:00:00 ora_lgwr_MAC_1
oracle   12636     1  0 08:48 ?        00:00:00 ora_lg00_MAC_1
oracle   12640     1  0 08:48 ?        00:00:00 ora_lg01_MAC_1
oracle   13206  7447  0 08:51 pts/2    00:00:00 grep lg

 

 

可以使用 10468 level 2 来trace adaptive scalable LGWR

 

 

[oracle@maclean1 trace]$ oerr ora 10468 
10468, 00000, "log writer debug module"
// *Document: NO
// *Cause:
// *Action: Set this event to the appropriate level for log writer debugging.
//

alter system set events '10468 trace name context  forever,level 2';

LGWR TRACE:
kcrfw_slave_adaptive_updatemode: time=426523948079110 scalable slave=1 arbiter=3 group0=10678 all=12733 delay=100 rw=98774 single=1973
48 scalable_nopipe=197548 scalable_pipe=108651 scalable=180439
kcrfw_slave_adaptive_savewritecounts: time=426523954275133 group0=10695 all=12752
kcrfw_slave_adaptive_savewritecounts: time=426523954662537 group0=10696 all=12753

CKPT TRACE:

*** 2013-07-07 10:52:21.528
kcrfw_slave_adaptive_saveredorate: time=426523941528521 curr=16649627696 prev=16635613056 rate=14014640 avg=14307212

*** 2013-07-07 10:52:24.553
kcrfw_slave_adaptive_saveredorate: time=426523944553556 curr=16664120996 prev=16649627696 rate=14493300 avg=14318490

 

 

 

实际测试可以发现 仅在redo 生成率非常高的环境中SCALABLE LGWR 对于redo写出的吞吐量有所帮助,进而提高OLTP环境的TPS。

_use_single_log_writer  = adaptive  2个LG slave进程:

 

Per Second Per Transaction Per Exec Per Call
DB Time(s): 2.8 0.0 0.00 0.33
DB CPU(s): 2.6 0.0 0.00 0.31
Redo size (bytes): 8,180,730.6 545.6
Logical read (blocks): 46,382.1 3.1
Block changes: 60,219.5 4.0

 

Function Name Reads: Data Reqs per sec Data per sec Writes: Data Reqs per sec Data per sec Waits: Count Avg Tm(ms)
LGWR 1M 0.14 .004M 4.3G 29.80 16.16M 1785 79.10

 

_use_single_log_writer  = true  使用single lgwr

 

Per Second Per Transaction Per Exec Per Call
DB Time(s): 2.8 0.0 0.00 0.34
DB CPU(s): 2.6 0.0 0.00 0.32
Redo size (bytes): 8,155,843.5 545.0
Logical read (blocks): 46,550.1 3.1
Block changes: 60,036.7 4.0

 

Function Name Reads: Data Reqs per sec Data per sec Writes: Data Reqs per sec Data per sec Waits: Count Avg Tm(ms)
LGWR 1M 0.13 .003M 4.8G 25.49 16.141M 1611 95.97

 

相关AWR附件:

_use_single_log_writer = adaptive

_use_single_log_writer = true

 

 

LGWR Scalability 的正面积极意义:

12c通过并发辅助进程以及优化的log file写算法有效改善 多CPU环境中由LGWR引起的等待瓶颈,释放LGWR性能。

一般来说这种性能改善在中小型的数据库实例中并不明显,实际上它们主要是为了那些64个CPU或更多CPU可用的数据库实例。但有性能测试报告显示在最少8个CPU的情况下对性能也有改善。

在之前的版本中,单一的LGWR处理所有的redo strands收集redo记录并将其写出到redo logfile中。在Oracle Database 12c中,LGWR开始并协调多个辅助helper进程,并行地完成以前LGWR一个人做的工作。

 

  • LGWR进程变成了多个LGnn形式的helper进程的协调指挥者,并负责保证这一堆并发进程所做的工作仍满足正确的LGWR顺序
  • LGnn进程负责读取一个或多个redo strands,负责实际写出到log file以及post前台进程

 

 

限制

在Oracle database 12c中,当使用SYNC同步redo传输方式传输redo到standby database时, 不支持使用上述的并行写SCALABLE LGWR,讲返回到串行写的老路子上。 但是Parallel LGWR/SCALABLE LGWR是支持ASYNC异步redo 传输的。

 

【12c新特性】12cR1 diff 11gR2 Hidden Parameters

【12c新特性】12cR1 diff 11gR2 Hidden Parameters

 

_ILM_FILTER_TIME 0 Upper filter time for ILM block compression
_ILM_FILTER_TIME_LOWER 0 Lower filter time for ILM block compression
_ILM_POLICY_NAME FALSE User specified ILM policy name
__data_transfer_cache_size 0 Actual size of data transfer cache
_abort_on_mrp_crash FALSE abort database instance when MRP crashes
_ac_enable_dscn_in_rac FALSE Enable Dependent Commit SCN tracking
_adaptive_scalable_log_writer_disable_worker_threshold 90 Percentage of overlap across multiple outstanding writes
_adaptive_scalable_log_writer_enable_worker_threshold 200 Increase in redo generation rate as a percentage
_adaptive_window_consolidator_enabled TRUE enable/disable adaptive window consolidator PX plan
_add_nullable_column_with_default_optim TRUE Allows add of a nullable column with default optimization
_adg_buffer_wait_timeout 10 Active Dataguard buffer wait time in cs
_adg_instance_recovery TRUE enable ADG instance recovery
_advanced_index_compression_options 0 advanced index compression options
_advanced_index_compression_options_value 20 advanced index compression options2
_advanced_index_compression_trace 0 advanced index compression trace
_allow_file_1_offline_error_1245 FALSE don’t signal ORA-1245 due to file 1 being offline
_alter_common_user_schema TRUE allow local user to create objects in common schema
_am_container_filesystem_ausize 4194304 allocation unit size for non-ASM containers
_am_max_containers 0 maximum number of containers
_am_max_groups 0 maximum number of containers
_am_max_seg_bytes 4000 maximum number of bytes per array segment
_am_timeouts_enabled TRUE enable timeouts
_am_trace_buffer_size 131072 size of per-process I/O trace buffer
_appqos_cdb_setting 0 QoSM CDB Performance Class Setting
_appqos_po_multiplier 1000 Multiplier for PC performance objective value
_aq_disable_x FALSE AQ – Disable new cross processes at an instance
_aq_dq_sessions 20 Deq session count
_aq_eq_sessions 10 Enq session count
_aq_init_shards 5 Minimum enqueue shards per queue at an instance
_aq_precrt_partitions 0 Precreate Partitions
_aq_pt_processes 1 Partition background processes
_aq_stop_backgrounds FALSE Stop all AQ background processes
_aq_subshard_Size 2000 Sub Shard Size
_aqsharded_cache_limit 0 Limit for cached enqueue/dequeue operations
_array_cdb_view_enabled TRUE array mode enabled for CDB views
_asm_access auto ASM File access mechanism
_asm_allow_unsafe_reconnect TRUE attempt unsafe reconnect to ASM
_asm_allowdegeneratemounts TRUE Allow force-mounts of DGs w/o proper quorum
_asm_dba_spcchk_thld 20000 ASM Disk Based Allocation Space Check Threshold
_asm_disable_ufg_dump FALSE disable terminated umbilicus diagnostic
_asm_disable_ufgmemberkill FALSE disable ufg member kill
_asm_diskerr_traces 2 Number of read/write errors per disk a process can trace
_asm_diskgroups2 disk groups to mount automatically set 2
_asm_diskgroups3 disk groups to mount automatically set 3
_asm_diskgroups4 disk groups to mount automatically set 4
_asm_enable_xrov FALSE Enable XROV capability
_asm_global_dump_level 267 System state dump level for ASM asserts
_asm_healthcheck_timeout 180 seconds until health check takes action
_asm_network_timeout 1 Keepalive timeout for ASM network connections
_asm_networks ASM network subnet addresses
_asm_nodekill_escalate_time 180 secs until escalating to nodekill if fence incomplete
_asm_noevenread_diskgroups List of disk groups having even read disabled
_asm_procs_trace_diskerr 5 Number of processes allowed to trace a disk failure
_asm_proxy_startwait 60 Maximum time to wait for ASM proxy connection
_asm_remote_client_timeout 300 timeout before killing disconnected remote clients
_asm_resyncCkpt 1024 number of extents to resync before flushing checkpoint
_asm_scrub_limit AUTO ASM disk scrubbing power
_asm_skip_diskval_check FALSE skip client side discovery for disk revalidate
_asm_trace_limit_timeout 30000 Time-out in milliseconds to reset the number of traces per disk and the number of processes allowed to trace
_autotask_test_name N/A Name of current Autotask Test (or test step)
_aux_dfc_keep_time 1440 auxiliary datafile copy keep time in minutes
_awr_cdbperf_threshold 21 Setting for AWR CDBPERF Threshold
_awr_mmon_deep_purge_all_expired FALSE Allows deep purge to purge AWR data for all expired snapshots
_awr_pdb_registration_enabled FALSE Parameter to enable/disable AWR PDB Registration
_awr_remote_target_dblink AWR Remote Target DBLink for Flushing
_backup_ksfq_bufmem_max 2.68E+08 maximum amount of memory (in bytes) used for buffers for backup/restore
_backup_min_ct_unused_optim 2097152 mimimun size in bytes of change tracking to apply unused space optimuzation
_bct_mrp_timeout 600 CTWR MRP wait timeout (seconds), zero to wait forever
_bct_public_dba_buffer_dynresize 2 allow dynamic resizing of public dba buffers, zero to disable
_bct_public_dba_buffer_maxsize 0 max buffer size permitted for public dba buffers, in bytes
_bg_spawn_diag_opts 0 background processes spawn diagnostic options
_block_level_offload_high_lat_thresh 40000 High Latency Threshold for Block Level Offload operations
_bloom_filter_size 0 bloom filter vector size (in KB)
_bloom_predicate_offload TRUE enables or disables bloom filter predicate offload to cells
_bloom_rm_filter FALSE remove bloom predicate in favor of zonemap join pruning predicate
_bloom_sm_enabled FALSE enable bloom filter optimization using slave mapping
_broadcast_scn_mode 1 broadcast-on-commit scn mode
_cache_orl_during_open ALL cache online logs
_cdb_compatible TRUE CDB Compatible
_cdb_rac_affinity TRUE rac affinity for parallel cdb operations
_cell_materialize_all_expressions FALSE Force materialization of all offloadable expressions on the cells
_cell_materialize_virtual_columns TRUE enable offload of expressions underlying virtual columns to cells
_cell_object_expiration_hours 24 flashcache object expiration timeout
_cell_offload_complex_processing TRUE enable complex SQL processing offload to cells
_cell_offload_expressions TRUE enable offload of expressions to cells
_cell_offload_sys_context TRUE enable offload of SYS_CONTEXT evaluation to cells
_cgs_comm_readiness_check 1 CGS communication readiness check
_cgs_memberkill_from_rim_instance FALSE allow a RIM instance to issue a CSS member kill
_cgs_msg_batch_size 4096 CGS message batch size in bytes
_cgs_msg_batching TRUE CGS message batching
_cgs_ticket_sendback 50 CGS ticket active sendback percentage threshold
_check_pdbid_in_redo FALSE Enable checking of pluggable database ID in redo
_cleanout_shrcur_buffers TRUE if TRUE, cleanout shrcur buffers
_cli_cachebktalloc 100 Percentage of memory to allocate
_client_enable_auto_unregister FALSE enable automatic unregister after a send fails with timeout
_clone_one_pdb_recovery FALSE Recover ROOT and only one PDB in clone database
_cloud_name gsm cloud name
_collect_tempundo_stats TRUE Collect Statistics v$tempundostat
_common_data_view_enabled TRUE common objects returned through dictionary views
_common_user_prefix C## Enforce restriction on a prefix of a Common User/Role/Profile name
_concurrency_chosen 10 what is the chosen value of concurrency
_controlfile_cell_flash_caching 3 Flash cache hint for control file accesses
_cpu_eff_thread_multiplier CPU effective thread multiplier
_crash_domain_on_exception 0 allow domain to exit for exceptions in any thread
_create_stat_segment 0 create ilm statistics segment
_ctx_doc_policy_stems FALSE enable ctx_doc.policy_stems api
_cu_row_locking 0 CU row level locking
_cursor_reload_failure_threshold 0 Number of failed reloads before marking cursor unusable
_cvmap_buffers 5000 Number of change vector buffers for multi instance media recovery
_data_transfer_cache_bc_perc_x100 500 Percentange * 100 of buffer cache to transfer to data transfer cache
_data_transfer_cache_size 0 Size of data transfer cache
_data_warehousing_scan_buffers TRUE if TRUE, enable data warehousing scan buffers
_datapump_compressbas_buffer_size 0 specifies buffer size for BASIC compression algorithm
_datapump_metadata_buffer_size 131072 specifies buffer size for metadata file I/O
_datapump_tabledata_buffer_size 262144 specifies buffer size for table data file I/O
_db_block_cache_history_lru FALSE buffer header tracing for lru operations
_db_block_prefetch_wasted_threshold_perc 2 Allowed wasted percent threshold of prefetched size
_db_dump_from_disk_and_efc 0 dump contents from disk and efc
_db_dw_scan_adaptive_cooling FALSE if TRUE, enable adaptive DW scan cooling
_db_dw_scan_max_shadow_count 5 DW Scan adaptive cooling max shadow count
_db_dw_scan_obj_cooling_factor 500 DW Scan object cooling factor to cool all temperatures
_db_dw_scan_obj_cooling_interval 100 DW Scan object cooling interval in number of scans, seconds, or pct of cache size
_db_dw_scan_obj_cooling_policy CACHE_SIZE DW scan objtect cooling policy
_db_dw_scan_obj_warming_increment 1000 DW Scan object warming increment when an object is scanned
_db_flash_cache_max_latency 400 Flash cache maximum latency allowed in 10 milliseconds
_db_flash_cache_max_outstanding_writes 32 Flash cache maximum outstanding writes allowed
_db_flash_cache_max_read_retry 3 Flash cache max read retry
_db_flash_cache_max_slow_io 3 Flash cache maximum slow io allowed
_db_num_gsm 0 database number in gsm dbpool
_dbfs_modify_implicit_fetch TRUE DBFS Link allows implicit fetch on modify – only on SecureFiles
_dbg_scan 0 generic scan debug
_dbop_enabled 1 Any positive number enables automatic DBOP monitoring. 0 is disabled
_dbpool_name gsm database pool name
_dd_validate_remote_locks TRUE GES deadlock detection validate remote locks
_deadlock_record_to_alert_log TRUE record resolved deadlocks to the alert log
_defer_sga_alloc_chunk_size 1.07E+09 Chunk size for defer sga allocation
_defer_sga_enabled FALSE Enable deferred shared memory allocation for SGA
_defer_sga_min_spsz_at_startup 5.37E+10 Minimum shared pool size at startup with deferred sga enabled
_defer_sga_min_total_defer_segs_sz 1.07E+11 Minimum total deferred segs size for defer sga allocation
_defer_sga_test_alloc_intv 0 SA** sleeps for N secs before allocating a deferred segment
_deferred_seg_in_seed TRUE Enable Deferred Segment Creation in Seed
_diag_test_seg_reinc_mode FALSE Sets trace segmentation to be in reincarnation mode
_diag_xm_enabled FALSE If TRUE, DIAG allows message exchanges across DB/ASM boundary
_disable_12cbigfile FALSE DIsable Storing ILM Statistics in 12cBigFiles
_disable_directory_link_check FALSE Disable directory link checking
_disable_flashback_recyclebin_opt TRUE Don’t use the Flashback Recyclebin optimization
_disable_rolling_patch 0 Disable Rolling Patch Feature
_dm_dmf_details_compatibility 12.1.0 set dm dmf details compatibility version
_dm_enable_legacy_dmf_output_types FALSE revert dmf output types to pre-12.1.0.1
_dnfs_rdma_enable 1 Enable dNFS RDMA transfers
_dnfs_rdma_max 1048576 Maximum size of dNFS RDMA transfer
_dnfs_rdma_min 8192 Minimum size of dNFS RDMA transfer
_drop_stat_segment 0 drop ilm statistics segment
_dump_10261_level 0 Dump level for event 10261, 1=>minimal dump 2=>top pga dump
_dump_scn_increment_stack Dumps scn increment stack per session
_emon_pool_inc 1 increment in EMON slaves per pool type
_emon_pool_max 10 maximum number of EMON slaves per pool type
_emon_pool_min 1 minimum number of EMON slaves per pool type
_emon_send_timeout 10000 send timeout after which the client is unregistered
_emx_control 0 EM Express control (internal use only)
_emx_max_sessions 128 Maximum number of sessions in the EM Express cache
_emx_session_timeout 3600 Session timeout (sec) in the EM Express cache
_enable_12g_bft TRUE enable 12g bigfile tablespace
_enable_columnar_cache 0 Enable Columnar Flash Cache Rewrite
_enable_heatmap_internal FALSE heatmap related – to be used by oracle dev only
_enable_iee_stats TRUE enables IEE stats gathering
_enable_ilm_flush_stats TRUE Enable ILM Stats Flush
_enable_ilm_testflush_stats FALSE Enable Test ILM Stats Flush
_enable_offloaded_writes FALSE Enable offloaded writes for Unit Test
_enable_pluggable_database FALSE Enable Pluggable Database
_enable_securefile_flashback_opt FALSE Enable securefile flashback optimization
_enqueue_deadlock_detect_all_global_locks FALSE enable deadlock detection on all global enqueues
_enqueue_sync_retry_attempts 3 max number of times the bg process to retry synchronous enqueue open if it failed because master could not allocate memory
_enqueue_sync_sim_mem_error FALSE simulate master instance running out of memory when synchronously getting a remotely mastered enqueue
_external_scn_logging_threshold_seconds 86400 High delta SCN threshold in seconds
_external_scn_rejection_delta_threshold_minutes 0 external SCN rejection delta threshold in minutes
_external_scn_rejection_threshold_hours 24 Lag in hours between max allowed SCN and an external SCN
_fast_index_maintenance TRUE fast global index maintenance during PMOPs
_fast_psby_conversion TRUE Enable fast physical standby conversion
_flush_ilm_stats 0 flush ilm stats
_force_logging_in_upgrade TRUE force logging during upgrade mode
_force_sys_compress TRUE Sys compress
_full_diag_on_rim FALSE rim nodes have full DIA* function
_gc_affinity_acquire_time TRUE if TRUE, save the time we acquired an affinity lock
_gc_async_send FALSE send blocks asynchronously
_gc_fg_spin_time 0 foreground msgq spin time
_gc_object_queue_max_length 0 maximum length for an object queue
_gc_save_cleanout TRUE if TRUE, save cleanout to apply later
_gc_split_flush FALSE if TRUE, flush index split redo before rejecting bast
_gc_temp_affinity FALSE if TRUE, enable global temporary affinity
_gcr_cpu_min_free 10 minimum amount of free CPU to flag an anomaly
_gcr_enable_high_memory_kill FALSE if TRUE, GCR may kill foregrounds under high memory load
_gcr_enable_new_drm_check FALSE if FALSE, revert to old drm load metric
_gcr_enable_statistical_cpu_check TRUE if FALSE, revert to old cpu load metric
_gcr_high_memory_threshold 10 minimum amount of Memory process must consume to be kill target
_gcr_max_rt_procs maximum number of RT DLM processes allowed by GCR
_gcr_mem_min_free 10 minimum amount of free memory to flag an anomaly
_gcs_disable_switch_role_with_writer TRUE if TRUE, disable switching to local role with a writer
_gcs_min_slaves 0 if non zero, it enables the minimum number of gcs slaves
_gcs_res_hash_buckets number of gcs resource hash buckets to be allocated
_gcs_reserved_resources 400 allocate the number of reserved resources in reconfiguration
_gcs_reserved_shadows 400 allocate the number of reserved shadows in reconfiguration
_ges_default_lmds * default lmds for enqueue hashing
_ges_direct_free FALSE if TRUE, free each resource directly to the freelist
_ges_direct_free_res_type CT string of resource types(s) to directly free to the freelist
_ges_dump_open_locks FALSE if TRUE, dump open locks for the LCK process during shutdown
_ges_fggl TRUE DLM fg grant lock on/off
_ges_freeable_res_chunk_free FALSE if TRUE, free dynamic resource chunks which are freeable
_ges_freeable_res_chunk_free_interval 180 time interval for freeing freeable dynamic resource chunks
_ges_gather_res_reuse_stats FALSE if TRUE, gather resource reuse statistics
_ges_hash_groups * enqueue hash table groups
_ges_lmd_mapping * enqueue to lmd mapping
_ges_nres_divide 0 how to divide number of enqueue resources among hash tables
_ges_resource_memory_opt 4 enable different level of ges res memory optimization
_ges_server_processes 1 number of background global enqueue server processes
_grant_secure_role FALSE Disallow granting of SR to NSR
_gsm GSM descriptions
_gsm_config_vers 0 version of gsm config
_gsm_cpu_thresh 75 CPU busy threshold
_gsm_drv_interval 30 metric derived values interval
_gsm_max_instances_per_db 8 maximum number of instances per database in gsm cloud
_gsm_max_num_regions 10 maximum number of regions in gsm cloud
_gsm_region_list List of GSM Regions
_gsm_srlat_thresh 20 Single block read latency threshold
_gsm_thresh_respct 50 threshold resource percentage
_gsm_thresh_zone 10 threshold zone
_gwm_spare1 gsm spare 1
_gwm_spare2 0 gsm spare 2
_gwm_spare3 0 gsm spare 3
_hang_base_file_count 5 Number of trace files for the normal base trace file
_hang_base_file_space_limit 20000000 File space limit for current normal base trace file
_hang_bool_spare1 TRUE Hang Management 1
_hang_cross_boundary_hang_detection_enabled TRUE Hang Management Cross Boundary detection
_hang_delay_resolution_for_libcache TRUE Hang Management delays hang resolution for library cache
_hang_hang_analyze_output_hang_chains TRUE if TRUE hang manager outputs hang analysis hang chains
_hang_int_spare2 FALSE Hang Management 2
_hang_log_verified_hangs_to_alert FALSE Hang Management log verified hangs to alert log
_hang_lws_file_space_limit 20000000 File space limit for current long waiting session trace file
_hang_monitor_archiving_related_hang_interval 300 Time in seconds ignored hangs must persist after verification
_hang_resolution_allow_archiving_issue_termination TRUE Hang Management hang resolution allow archiving issue termination
_hang_terminate_session_replay_enabled FALSE Hang Management terminates sessions allowing replay
_hashops_prefetch_size 4 maximum no of rows whose relevant memory locations are prefetched
_heatmap_format_1block FALSE heatmap related – to be used by oracle dev only
_heatmap_min_maxsize 0 Internal testing only
_hm_xm_enabled TRUE If TRUE, DIA0 allows message exchanges across DB/ASM boundary
_ilm_mem_limit 10 percentage of the max shared pool heat-map can use – internal
_ilmflush_stat_limit 0 ILM flush statistics limit – Internal testing only
_ilmset_stat_limit 0 ILM set statistics limit – Internal testing only
_ilmstat_memlimit 10 Percentage of shared pool for use by ILM Statistics
_image_redo_gen_delay 0 Image redo generation delay in centi-seconds (direct write mode)
_imr_rr_holder_kill_time 300 IMR max time instance is allowed to hold RR lock in seconds
_index_load_buf_oltp_sacrifice_pct 10 index load buf oltp sacrifice pct
_index_load_buf_oltp_under_pct 85 index load buf and comp oltp under-estimation pct
_index_max_inc_trans_pct 20 max itl expand percentage soft limit during index insert
_io_internal_test 0 I/O internal testing parameter
_io_osd_param 1 OSD specific parameter
_io_outlier_threshold 500 Latency threshold for io_outlier table
_ka_allow_reenable FALSE reenability of kernel accelerator service after disable
_ka_compatibility_requirement all kernel accelerator compatibility operation requirement
_ka_doorbell 0 kernel accelerator doorbell mode
_ka_locks_per_sector 4 locks per sector in kernel accelerator
_ka_mode 0 kernel accelerator mode
_ka_msg_reap_count 40 maximum number of KA messages to receive and process per wait
_ka_pbatch_messages TRUE kernel accelerator perform pbatch messages
_kcfis_automem_level 1 Set auto memory management control for kcfis memory allocation
_kcfis_cell_passthru_dataonly TRUE Allow dataonly passthru for smart scan
_kcfis_celloflsrv_passthru_enabled FALSE Enable offload server usage for passthru operations
_kcfis_celloflsrv_usage_enabled TRUE Enable offload server usage for offload operations
_kcfis_qm_prioritize_sys_plan TRUE Prioritize Quaranitine Manager system plan
_kcfis_qm_user_plan_name Quaranitine Manager user plan name
_kdizoltp_uncompsentinal_freq 16 kdizoltp uncomp sentinal frequency
_kdlf_read_flag 0 kdlf read flag
_kdli_descn_adj FALSE coalesce extents with deallocation scn adjustment
_kdli_mts_so TRUE use state objects in shared server for asyncIO pipelines
_kdli_ralc_length 10485760 lob length threshold to trigger rounded allocations
_kdli_ralc_rounding 1048576 rounding granularity for rounded allocations
_kdz_pred_nrows 32767 Number of rows to predicate at a time in kdzt
_kdz_proj_nrows 1024 Number of rows to project at a time in kdzt
_kecap_cache_size 10240 Workload Replay INTERNAL parameter used to set memory usage in  Application Replay
_kffmlk_hash_size 512 size of kffmlk_hash table
_kffmop_chunks 42 number of chunks of kffmop’s
_kgl_cap_hd_alo_stacks FALSE capture stacks for library cache handle allocation
_kjac_force_outcome_current_session FALSE if TRUE, enable to run force outcome on the current session
_kjdd_call_stack_dump_enabled FALSE Enables printing of short call stack with the WFG
_kjdd_wfg_dump_cntrl 0 To control the way Wait-For_Graph is dumped
_kjltmaxgt 1000 record latch requests that takes longer than this many us
_kjltmaxht 1000 record latch reqeust that are held longer than this many us
_kjlton FALSE track DLM latch usage on/off
_kqdsn_max_instance_bits 8 maximum bits used for instance value in sequence partition
_kqdsn_min_instance_bits 0 minimum bits used for instance value in sequence partition
_kqdsn_partition_ratio 30 ratio of instance to session bits in sequence partition
_kqr_optimistic_reads FALSE optimistic reading of row cache objects
_ksipc_libipc_path over-ride default location of libipc
_ksipc_mode 0 ksipc mode
_ksipc_spare_param1 0 ksipc spare param 1
_ksipc_spare_param2 ksipc spare param 2
_ksipc_wait_flags 0 tune ksipcwait
_ksmlsaf 0 KSM log alloc and free
_ksv_slave_exit_timeout 120 slave exit timeout
_ksxp_skgxp_ant_options SKGXP ANT options
_ksxp_skgxp_inets limit SKGXP networks
_ktilmsc_exp 600 expiration time of ktilm segment cache (in second)
_ktspsrch_scchk 60 cleanout check time of space search cache
_ktspsrch_scexp 60 expiration time of space search cache
_ktst_rss_max 1000 maximum temp extents to be released across instance
_ktst_rss_min 100 minimum temp extents to be released across instance
_ktst_rss_retry 2 maximum retries of sort segment release
_kxdbio_ctx_init_count 32 initial count of KXDBIO state object
_kxdbio_disable_offload_opcode 0 KXDBIO Disable offload for the set opcodes.  Value is a Bitmap of    0×00000001 – disable cell to cell data copy offload    0×00000002 – disable disk scrubbing offload to cell    0×00000004 – disable offloaded writes to cell
_kxdbio_enable_ds_opcode 0 KXDBIO Enable Dumb storage simulation for the set opcodes.
_kxdbio_hca_loadavg_thresh 98 HCA loadavg threshold at which writes need to get offloaded
_kxdbio_ut_ctl 0 kxdbio unit test controls
_latch_wait_list_pri_sleep_secs 1 Time to sleep on latch wait list until getting priority
_ldr_tempseg_threshold 8388608 amount to buffer prior to allocating temp segment (extent sizing)
_lgwr_io_outlier 0 LGWR I/O outlier frequency
_lm_big_cluster_optimizations FALSE enable certain big cluster optimizations in drm
_lm_comm_channel ksxp GES communication channel type
_lm_comm_msgq_busywait 10 busy wait time in microsecond for msgq
_lm_comm_reap_count 1 message reap count for receive
_lm_comm_tkts_add_factor 10 Ticket allocation addition factor
_lm_comm_tkts_calc_period_length 5 Weighted average calculation interval length (second)
_lm_comm_tkts_max_periods 10 Max number of periods used in weighted avearage calculation
_lm_comm_tkts_min_decrease_wait 120 Time to wait before allowing an allocation decrease
_lm_comm_tkts_min_increase_wait 25 Time to wait before allowing an allocation increase
_lm_comm_tkts_mult_factor 200 Ticket allocation multiplication factor
_lm_comm_tkts_nullreq_threshold 25 Null request frequency threshold (percentage)
_lm_drmopt12 8 enable drm scan optimizations in 12
_lm_drmopt12_nolatch TRUE enable drm latching optimizations in 12
_lm_enqueue_blocker_dump_timeout_cnt 30 enqueue blocker dump timeout count
_lm_fdrm_stats FALSE gather full drm statistics
_lm_hashtable_bkt_high 5 High element threshold in hash table bucket
_lm_hashtable_bkt_low 3 Low element threshold in hash table bucket
_lm_hashtable_bkt_thr 70 Threshold for hash table resizing
_lm_hb_acceptable_hang_condition default list of acceptable hang conditions in heartbeat check
_lm_hb_enable_acl_check TRUE to enable the wait analysis with acceptable condition lists
_lm_hb_exponential_hang_time_factor 2 heartbeat exponential hang time multiplier
_lm_hb_maximum_hang_report_count 20 maximum heartbeat hang report count
_lm_idle_connection_kill_max_skips 1 GES idle connection max skip kill request
_lm_idle_connection_max_ignore_kill_count 2 GES maximum idle connection kill request ignore count
_lm_idle_connection_quorum_threshold 50 GES idle connection health quorum threshold
_lm_lms_opt_priority TRUE enable freeslot lms priority optimization
_lm_lms_priority_check_frequency 60000 frequency of LMS priority decisions in milliseconds
_lm_msg_pool_dump_threshold 20000 GES message pool dump threshold in terms of buffer count
_lm_num_bnft_stats_buckets 1 number of buckets in the benefit stats hash table
_lm_process_lock_q_scan_limit 100 limit on scanning process lock queue instead of resource convert lock queue
_lm_res_tm_hash_bucket 0 number of extra TM resource hash buckets
_lm_resend_open_convert_timeout 30 timeout in secs before resubmitting the open-convert
_lm_rm_slaves 1 if non zero, it enables remastering slaves
_lm_wait_pending_send_queue TRUE GES wait on pending send queue
_lock_ref_constraint_count 50 number of nowait attempts to lock referential constraint
_log_undo_df_info FALSE generate marker to log file# that belong to undo tablespace
_log_write_info_size 4096 Size of log write info array
_log_writer_worker_dlm_hearbeat_update_freq 5000 LGWR worker DLM health-monitoring heartbeat update frequency (ms)
_lthread_cleanup_intv_secs 5 interval for cleaning lightweight threads in secs
_lthread_clnup_hk_wait_secs 3 timeout after hard killing operation for lthread to exit
_lthread_clnup_pmon_softkill_wait_secs 1 wait timeout for PMON between soft kill and hard kill of lthreads
_lthread_clnup_spawner_sk_wait_secs 30 timeout for spawner between soft kill and hard kill of lthreads
_lthread_debug FALSE Enable Debugging mode for lightweight threads
_lthread_enabled TRUE Enable lightweight threads
_lthread_max_spawn_time_csecs 12000 maximum time interval a spawner will wait for a lthread to get ready
_lthread_spawn_check_intv_ms 10 time interval for a spawner to check for spawnee to get ready
_lthread_step_debugging FALSE Enable Step wise Debugging mode for lightweight threads
_max_clients_per_emon 256 maximum number of clients per emon
_max_data_transfer_cache_size 5.37E+08 Maximum size of data transfer cache
_max_defer_gran_xfer_atonce 10 Maximum deferred granules transferred by MMAN atonce
_max_incident_file_size Maximum size (in KB, MB, GB, Blocks) of incident dump file
_max_kcnibr_ranges 1048576 Max number of nonlogged data block ranges
_max_log_write_io_parallelism 1 Maximum I/O parallelism within a log write (auto=0)
_max_log_write_parallelism 1 Maximum parallelism within a log write (auto=0)
_max_outstanding_log_writes 2 Maximum number of outstanding redo log writes
_max_queued_report_requests 300 Maximum number of report requests that can be queued in a list
_max_report_flushes_percycle 5 Max no of report requests that can be flushed per cycle
_max_string_size_bypass 0 controls error checking for the max_string_size parameter
_max_sys_next_extent 0 Dictionary managed SYSTEM tablespace maximum next extent size in MB (allowed range [16-4095], 0 if unlimited)
_memory_max_tgt_inc_cnt 0 counts the times checker increments memory target
_midtier_affinity_cluswait_prc_threshold 6 cluster wait precentage threshold to enter affinity
_min_time_between_psp0_diag_secs 300 minimum time between PSP0 diagnostic used for flow control
_modify_column_index_unusable FALSE allow ALTER TABLE MODIFY(column) to violate index key length limit
_mpmt_enabled_backgrounds * mpmt enabled backgrounds
_mpmt_fg_enabled FALSE MPMT mode foreground enabled
_mpmt_procs_per_osp 100 max procs per osp
_multi_transaction_optimization_enabled TRUE reduce SGA memory use during create of a partitioned table
_mv_add_log_placeholder TRUE add log placeholder
_mv_cleanup_orphaned_metadata TRUE cleanup orphaned materialized view metadata
_mv_complete_refresh_conventional FALSE use conventional INSERTs for MV complete refresh
_mv_deferred_no_log_age_val TRUE avoid build deferred MV log age validate
_mv_expression_extend_size 4096 MV expression extend size
_mv_refresh_insert_no_append TRUE materialized view refresh using insert no append
_nameservice_consistency_check TRUE NameService Consistency check switch
_net_timeout_latency 0 NET_TIMEOUT latency
_no_small_file FALSE Not to apply new extent scheme for small file temp spaces
_no_stale_joinback_rewrite FALSE No joinbacks if mv is stale
_nologging_kcnbuf_hash_buckets 1024 Number of nologging buffer hash buckets
_nologging_kcnbuf_hash_latches 256 Number of nologging buffer hash latches
_nologging_load_slotsz 1048576 Nologging standby: direct load buffer size
_nologging_sdcl_append_wait 100 Nologging standby append sdcl wait time
_nologging_sendbuf_ratio 99 Nologging standby: outstanding send buffer ratio
_nologging_txn_cmt_wait 1500 Nologging standby transaction commit wait time
_noncdb_to_pdb FALSE converting a non-cdb to a pdb
_numa_shift_enabled TRUE Enable NUMA shift
_numa_shift_value 0 user defined value for numa nodes shift
_number_group_memberships_per_cache_line 3 maximum number of group memberships per cache line
_odci_aggregate_save_space FALSE trade speed for space in user-defined aggregation
_olap_row_load_time_precision DEFAULT OLAP Row Load Time Precision
_old_extent_scheme FALSE Revert to old extent allocation
_oltp_comp_dbg_scan 0 oltp compression scan debug
_oltp_spill FALSE spill rows for oltp compression if loader pga limit is exceeded
_omni_enqueue_enable 1 Enable Omni Enqueue feature (0 = disable, 1 = enable on ASM (default), 2 = enable)
_online_ctas_diag 0 controls dumping diagnostic information for online ctas
_optimizer_adaptive_plan_control 0 internal controls for adaptive plans
_optimizer_adaptive_plans TRUE enable adaptive plans
_optimizer_ads_max_table_count 0 maximum number of tables in a join under ADS
_optimizer_ads_time_limit 0 maximum time limit (seconds) under ADS
_optimizer_ads_use_result_cache TRUE use result cache for ADS queries
_optimizer_ansi_join_lateral_enhance TRUE optimization of left/full ansi-joins and lateral views
_optimizer_ansi_rearchitecture TRUE re-architecture of ANSI left, right, and full outer joins
_optimizer_batch_table_access_by_rowid TRUE enable table access by ROWID IO batching
_optimizer_cluster_by_rowid TRUE enable/disable the cluster by rowid feature
_optimizer_cluster_by_rowid_control 3 internal control for cluster by rowid feature mode
_optimizer_cube_join_enabled TRUE enable cube join
_optimizer_dsdir_usage_control 126 controls optimizer usage of dynamic sampling directives
_optimizer_gather_feedback TRUE optimizer gather feedback
_optimizer_gather_stats_on_load TRUE enable/disable online statistics gathering
_optimizer_generate_transitive_pred TRUE optimizer generate transitive predicates
_optimizer_hybrid_fpwj_enabled TRUE enable hybrid full partition-wise join when TRUE
_optimizer_multi_table_outerjoin TRUE allows multiple tables on the left of outerjoin
_optimizer_null_accepting_semijoin TRUE enables null-accepting semijoin
_optimizer_partial_join_eval TRUE partial join evaluation parameter
_optimizer_performance_feedback OFF controls the performance feedback
_optimizer_proc_rate_level BASIC control the level of processing rates
_optimizer_proc_rate_source DEFAULT control the source of processing rates
_optimizer_strans_adaptive_pruning TRUE allow adaptive pruning of star transformation bitmap trees
_optimizer_unnest_scalar_sq TRUE enables unnesting of of scalar subquery
_optimizer_use_gtt_session_stats TRUE use GTT session private statistics
_optimizer_use_histograms TRUE enable/disable the usage of histograms by the optimizer
_oracle_script FALSE Running an Oracle-supplied script
_parallel_blackbox_sga TRUE true if blackbox will be allocated in SGA, false if PGA
_parallel_ctas_enabled TRUE enable/disable parallel CTAS operation
_parallel_fault_tolerance_threshold 3 total number of faults fault-tolerance will handle
_part_access_version_by_number TRUE use version numbers to access versioned objects for partitioning
_part_redef_global_index_update TRUE online partition redefinition update global indexes
_partition_advisor_srs_active TRUE enables sampling based partitioning validation
_partition_cdb_view_enabled TRUE partitioned cdb view evaluation enabled
_pdb_use_sequence_cache TRUE Use sequence cache in PDB mode
_pga_limit_check_wait_time 1000000 microseconds to wait for over limit confirmation
_pga_limit_dump_summary FALSE dump PGA summary when signalling ORA-4036
_pga_limit_interrupt_smaller FALSE whether to interrupt smaller eligible processes
_pga_limit_min_req_size 4194304 bytes of PGA usage below which process will not get ORA-4036
_pga_limit_simulated_physmem_size 0 bytes of physical memory to determine pga_aggregate_limit with
_pga_limit_target_perc 200 default percent of pga_aggregate_target for pga_aggregate_limit
_pga_limit_time_to_interrupt 2 seconds to wait until direct interrupt
_pga_limit_time_until_idle 15 seconds to wait before treating process as idle
_pga_limit_time_until_killed 30 seconds to wait before killing session over limit
_pga_limit_tracing 0 trace pga_aggregate_limit activity
_pga_limit_use_immediate_kill TRUE use immediate kill for sessions over limit
_pga_limit_watch_perc 50 percentage of limit to have processes watch
_pga_limit_watch_size 1.05E+08 bytes of PGA usage at which process will begin watching limit
_pin_time_statistics FALSE if TRUE collect statistics for how long a current pin is held
_ping_wait_for_log_force TRUE Wait for log force before block ping
_pluggable_database_debug 0 Debug flag for pluggable database related operations
_pred_push_cdb_view_enabled TRUE predicate pushdown enabled for CDB views
_prefered_standby standby db_unique_name prefered for krb operations
_print_inmem_heatmap 0 print inmem ilm heatmap
_print_stat_segment 0 print ilm statistics segment
_px_adaptive_dist_method CHOOSE determines the behavior of adaptive distribution methods
_px_adaptive_dist_method_threshold 0 Buffering / decision threshold for adaptive distribution methods
_px_adaptive_offload_percentage 30 percentage for PQ adaptive offloading of granules
_px_back_to_parallel OFF allow going back to parallel after a serial operation
_px_cdb_view_enabled TRUE parallel cdb view evaluation enabled
_px_concurrent TRUE enables pq with concurrent execution of serial inputs
_px_cpu_autodop_enabled TRUE enables or disables auto dop cpu computation
_px_cpu_operator_bandwidth CPU operator bandwidth in MB/sec for DOP computation
_px_cpu_process_bandwidth 200 CPU process bandwidth in MB/sec for DOP computation
_px_dp_array_size 32767 Max number of pq processes supported
_px_filter_parallelized TRUE enables or disables correlated filter parallelization
_px_filter_skew_handling TRUE enable correlated filter parallelization to handle skew
_px_groupby_pushdown FORCE perform group-by pushdown for parallel query
_px_hybrid_TSM_HWMB_load TRUE Enable Hybrid Temp Segment Merge/High Water Mark Brokered load method
_px_join_skew_handling TRUE enables skew handling for parallel joins
_px_join_skew_minfreq 30 sets minimum frequency(%) for skewed value for parallel joins
_px_join_skew_ratio 10 sets skew ratio for parallel joins
_px_load_balancing_policy UNIFORM parallel load balancing policy
_px_load_monitor_threshold 10000 threshold for pushing information to load slave workload monitor
_px_message_compression TRUE enable compression of control messages for parallel query
_px_monitor_load FALSE enable consumer load slave workload monitoring
_px_object_sampling 200 parallel query sampling for base objects (100000 = 100%)
_px_object_sampling_enabled TRUE use base object sampling when possible for range distribution
_px_onepass_slave_acquisition TRUE enable/disable one pass slave acquisition for parallel execution
_px_parallelize_expression TRUE enables or disables expression evaluation parallelization
_px_partial_rollup_pushdown ADAPTIVE perform partial rollup pushdown for parallel execution
_px_proactive_slave_alloc_threshold 8 parallel proactive slave allocation threshold/unit
_px_pwmr_enabled TRUE parallel partition wise match recognize enabled
_px_replication_enabled TRUE enables or disables replication of small table scans
_px_single_server_enabled TRUE allow single-slave dfo in parallel query
_px_tq_rowhvs TRUE turn on intra-row hash valueing sharing in TQ
_px_wif_dfo_declumping CHOOSE NDV-aware DFO clumping of multiple window sorts
_px_wif_extend_distribution_keys TRUE extend TQ data redistribution keys for window functions
_px_wif_min_ndv_per_slave 2 mininum NDV of TQ keys needed per slave for scalable WiF PX
_radm_enabled TRUE Data Redaction
_re_fast_sql_operator all enables fast boxable sql operator
_re_independent_expression_cache_size 20 defines max number of compiled cached expressions for iee
_re_num_complex_operator 1000 defines max number of compiled complex operator per ruleset-iee
_re_num_rowcache_load 2 defines max number of complex operators loaded with row cache
_re_result_cache_keysiz 20 defines max number key for result cache hash table
_re_result_cache_size 20 defines max number of cached elements for result cache
_read_mostly_enable_logon FALSE Read mostly instances enable non-privileged logons
_read_mostly_instance FALSE indicates this is a read_mostly instance
_read_mostly_instance_qa_control 0 internal parameter to control read mostly instance QA
_read_mostly_slave_timeout 20000 Time to wait on read mostly node when hub not available
_realfree_heap_pagesize 65536 hint for real-free page size in bytes
_realfree_pq_heap_pagesize 65536 hint for pq real-free page size in bytes
_redef_on_statement FALSE Use on-statement refresh in online redefinition
_redo_log_debug_config 0 Various configuration flags for debugging redo logs
_redo_log_record_life 168 Life time in hours for redo log table records
_region_name gsm region name
_relocate_pdb FALSE Relocate PDB to another RAC instance after it is closed in the current instance
_remote_asm remote ASM configuration
_remote_awr_enabled FALSE Enable/disable Remote AWR Mode
_remove_exf_component TRUE enable/disable removing of components EXF and RUL during upgrade
_report_capture_cycle_time 60 Time (in sec) between two cycles of report capture daemon
_report_capture_dbtime_percent_cutoff 50 100X Percent of system db time daemon is allowed over 10 cycles
_report_capture_recharge_window 10 No of report capture cycles after which db time is recharged
_report_capture_timeband_length 1 Length of time band (in hours) in the reports time bands table
_report_request_ageout_minutes 60 Time (in min) after which a report request is deleted from queue
_resource_includes_unlimited_tablespace FALSE Whether RESOURCE role includes UNLIMITED TABLESPACE privilege
_result_cache_deterministic_plsql FALSE result cache deterministic PLSQL functions
_resumable_critical_alert 0 raise critical alert for resumable failure
_rman_roundrobin_placement Numa round robin placement for RMAN procs
_rond_test_mode 0 rac one node test mode
_rowlen_for_chaining_threshold 1000 maximum rowlen above which rows may be chained across blocks
_rowsets_cdb_view_enabled TRUE rowsets enabled for CDB views
_rowsets_enabled TRUE enable/disable rowsets
_rowsets_max_rows 200 maximum number of rows in a rowset
_rowsets_target_maxsize 524288 target size in bytes for space reserved in the frame for a rowset
_rtaddm_trigger_args comma-separated list of numeric arguments for RT addm trigger
_rtaddm_trigger_enabled TRUE To enable or disable Real-Time ADDM automatic trigger
_scalar_type_lob_storage_threshold 4000 threshold for VARCHAR2, NVARCHAR2, and RAW storage as BLOB
_securefile_log_num_latches 0 Maximum number of open descriptors for securefile log
_securefile_log_shared_pool_size 0 Size of securefile log buffer pool from SGA
_securefiles_breakreten_retry 5 segment retry before dishonoring retention
_securefiles_spcutl FALSE securefiles segment utl optimization
_serial_log_write_worker_io FALSE Serialize log write slave I/O
_set_container_service DEFAULT set container service
_sf_default_enabled TRUE enable 12g securefile default
_sga_alloc_slaves_term_timeout_secs 120 Termination timeout in secs for SA** slaves
_shrd_que_tm_processes 1 number of sharded queue Time Managers to start
_shrd_que_tm_statistics_duration 0 Shaded queue statistics collection window duration
_simulated_log_write_usecs 0 Simulated latency of log writes (usecs)
_skgxp_ant_options SKGXP ANT options (oss)
_skip_acfs_checks FALSE Override checking if on an ACFS file system
_smm_max_size_static 92160 static maximum work area size in auto mode (serial)
_smm_px_max_size_static 230400 static maximum work area size in auto mode (global)
_snapshot_recovery_enabled TRUE enable/disable snapshot recovery
_sort_sync_min_spill_threshold 90 controls the mininum spill size for synchronized spill (in percent)
_sort_sync_min_spillsize 262144 controls the size of mininum run size for synchronized spill (in kb)
_sql_diag_repo_origin all duarations where sql diag repository are retained
_sql_diag_repo_retain retain sql diag repository to cursor or not
_sql_hvshare_debug 1 control hash value sharing debug level
_sql_hvshare_threshold 0 threshold to control hash value sharing across operators
_sql_plan_directive_mgmt_control 3 controls internal SQL Plan Directive management activities
_sql_show_expreval FALSE show expression evalution as shared hash producer in plan
_stat_aggs_one_pass_algorithm FALSE enable one pass algorithm for variance-related functions
_suppress_identifiers_on_dupkey FALSE supress owner index name err msg
_switch_current_scan_scn TRUE switch current uses scan scn
_switchover_timeout 0 Switchover timeout in minutes
_sys_logon_delay 1 failed logon delay for sys
_target_log_write_size 0 Do log write if this many redo blocks in buffer (auto=0)
_target_log_write_size_timeout 1 How long LGWR will wait for redo to accumulate (csecs)
_temp_undo_disable_adg FALSE is temp undo disabled on ADG
_test_hm_extent_map FALSE heatmap related – to be used by oracle dev only
_test_param_7 test parameter 7 – big integer list
_test_param_8 20 test parameter 8 – cdb tests
_thread_state_change_timeout_pnp 1800 Thread state change timeout for PnP instance (in sec)
_time_based_rcv_ckpt_target 0 time-based incremental recovery checkpoint target in sec
_time_based_rcv_hdr_update_interval 0 time-based incremental recovery file header update interval in sec
_trace_ktfs FALSE Trace ILM Stats Tracking
_trace_ktfs_mem FALSE Debug memleak
_trace_temp FALSE Trace Tempspace Management
_track_metrics_memory TRUE Enable/disable Metrics Memory Tracking
_tsenc_obfuscate_key BOTH Encryption key obfuscation in memory
_twenty-eighth_spare_parameter FALSE twenty-eighth spare parameter – boolean
_twenty-fifth_spare_parameter twenty-fifth spare parameter – string list
_twenty-first_spare_parameter twenty-first spare parameter – string list
_twenty-fourth_spare_parameter twenty-fourth spare parameter – string list
_twenty-second_spare_parameter twenty-second spare parameter – string list
_twenty-seventh_spare_parameter FALSE twenty-seventh spare parameter – boolean
_twenty-sixth_spare_parameter FALSE twenty-sixth spare parameter – boolean
_twenty-third_spare_parameter twenty-third spare parameter – string list
_txn_control_trace_buf_size 4096 size the in-memory buffer size of txn control
_unified_audit_flush_interval 3 Unified Audit SGA Queue Flush Interval
_unified_audit_flush_threshold 85 Unified Audit SGA Queue Flush Threshold
_unified_audit_policy_disabled FALSE Disable Default Unified Audit Policies on DB Create
_upddel_dba_hash_mask_bits 0 controls masking of lower order bits in DBA
_use_fips_mode FALSE Enable use of crypographic libraries in FIPS mode
_use_hidden_partitions FALSE use hidden partitions
_use_single_log_writer ADAPTIVE Use a single process for redo log writing
_utlmmig_table_stats_gathering TRUE enable/disable utlmmig table stats gathering at upgrade
_uts_first_segment_retain TRUE Should we retain the first trace segment
_uts_first_segment_size 0 Maximum size (in bytes) of first segments
_uts_trace_disk_threshold 0 Trace disk threshold parameter
_uts_trace_segment_size 0 Maximum size (in bytes) of a trace segment
_uts_trace_segments 5 Maximum number of trace segments
_validate_metric_groups FALSE Enable/disable SGA Metric Structure validation
_wcr_grv_cache_size 65535 Oracle internal: Set the replay cache size for WRR$_REPLAY_DATA.
_wcr_seq_cache_size 65535 Oracle internal: Set the replay cache size for WRR$_REPLAY_SEQ_DATA.
_widetab_comp_enabled TRUE wide table compression enabled
_xa_internal_retries 600 number of internal retries for xa transactions
_xds_max_child_cursors 100 Maximum number of XDS user-specific child cursors
_xs_cleanup_task TRUE Triton Session Cleanup
_xs_dispatcher_only FALSE XS dispatcher only mode
_zonemap_control 0 control different uses/algorithms related to zonemaps
_zonemap_staleness_tracking 1 control the staleness tracking of zonemaps via trigger
_zonemap_use_enabled TRUE enable the use of zonemaps for IO pruning
cell_offloadgroup_name Set the offload group name
connection_brokers ((TYPE=DEDICATED)(BROKERS=1)), ((TYPE=EMON)(BROKERS=1)) connection brokers specification
db_big_table_cache_percent_target 0 Big table cache target size in percentage
db_index_compression_inheritance NONE options for table or tablespace level compression inheritance
dnfs_batch_size 4096 Max number of dNFS asynch I/O requests queued per session
enable_pluggable_database TRUE Enable Pluggable Database
heat_map OFF ILM Heatmap Tracking
max_string_size STANDARD controls maximum size of VARCHAR2, NVARCHAR2, and RAW types in SQL
noncdb_compatible FALSE Non-CDB Compatible
optimizer_adaptive_features TRUE controls adaptive features
optimizer_adaptive_reporting_only FALSE use reporting-only mode for adaptive optimizations
parallel_degree_level 100 adjust the computed degree in percentage
parallel_fault_tolerance_enabled FALSE enables or disables fault-tolerance for parallel statement
pdb_file_name_convert PDB file name convert patterns and strings for create cdb/pdb
pga_aggregate_limit 2.15E+09 limit of aggregate PGA memory consumed by the instance
spatial_vector_acceleration FALSE enable spatial vector acceleration
temp_undo_enabled FALSE is temporary undo enabled
threaded_execution FALSE Threaded Execution Mode
unified_audit_sga_queue_size 1048576 Size of Unified audit SGA Queue
use_dedicated_broker FALSE Use dedicated connection broker

【12c新特性】CBO Optimizer优化器新特性列表

【12c新特性】CBO Optimizer新隐藏参数,以下Optimizer优化器新特性列表,通过对比 12c R1 和 11gR2的10053 trace中有影响的优化器参数获得:

 

CLI_internal_cursor
PMO_altidx_rebuild
_adaptive_window_consolidator_enabled
_arch_comp_dbg_scan
_array_cdb_view_enabled
_bloom_filter_size
_bloom_predicate_offload
_bloom_rm_filter
_bloom_sm_enabled
_cell_materialize_all_expressions
_cell_materialize_virtual_columns
_cell_offload_complex_processing
_cell_offload_expressions
_cell_offload_sys_context
_common_data_view_enabled
_dbg_scan
_fast_index_maintenance
_hashops_prefetch_size
_long_varchar_allow_IOT
_multi_commit_global_index_maint
_oltp_comp_dbg_scan
_optimizer_adaptive_plans
_optimizer_ads_max_table_count
_optimizer_ads_time_limit
_optimizer_ads_use_result_cache
_optimizer_ansi_join_lateral_enhance
_optimizer_ansi_rearchitecture
_optimizer_batch_table_access_by_rowid
_optimizer_cluster_by_rowid
_optimizer_cluster_by_rowid_control
_optimizer_cube_join_enabled
_optimizer_dsdir_usage_control
_optimizer_gather_feedback
_optimizer_gather_stats_on_load
_optimizer_generate_transitive_pred
_optimizer_hybrid_fpwj_enabled
_optimizer_multi_table_outerjoin
_optimizer_null_accepting_semijoin
_optimizer_partial_join_eval
_optimizer_performance_feedback
_optimizer_proc_rate_level
_optimizer_proc_rate_source
_optimizer_strans_adaptive_pruning
_optimizer_unnest_scalar_sq
_optimizer_use_gtt_session_stats
_optimizer_use_histograms                        ==>10g已有
_parallel_ctas_enabled
_parallel_fault_tolerance_threshold
_partition_advisor_srs_active
_partition_cdb_view_enabled
_pred_push_cdb_view_enabled
_px_adaptive_dist_method
_px_adaptive_dist_method_threshold
_px_back_to_parallel
_px_cdb_view_enabled
_px_concurrent
_px_cpu_autodop_enabled
_px_cpu_process_bandwidth
_px_filter_parallelized
_px_filter_skew_handling
_px_groupby_pushdown
_px_hybrid_TSM_HWMB_load
_px_join_skew_handling
_px_join_skew_minfreq
_px_join_skew_ratio
_px_load_monitor_threshold
_px_loc_msg_cost
_px_monitor_load
_px_net_msg_cost
_px_object_sampling_enabled
_px_parallelize_expression
_px_partial_rollup_pushdown
_px_pwmr_enabled
_px_replication_enabled
_px_single_server_enabled
_px_tq_rowhvs
_px_wif_dfo_declumping
_px_wif_extend_distribution_keys
_rowsets_cdb_view_enabled
_rowsets_enabled
_rowsets_max_rows
_rowsets_target_maxsize
_smm_max_size_static
_smm_px_max_size_static
_sql_hvshare_threshold
_stat_aggs_one_pass_algorithm
_upddel_dba_hash_mask_bits
_use_hidden_partitions
_zonemap_control
_zonemap_use_enabled
ilm_access_tracking
ilm_dml_timestamp
ilm_filter
optimizer_adaptive_features
optimizer_adaptive_reporting_only
parallel_degree_level
parallel_execution_message_size
parallel_fault_tolerance_enabled
sqlstat_enabled

==============================================================================================》

_adaptive_window_consolidator_enabled TRUE enable/disable adaptive window consolidator PX plan
_arch_comp_dbg_scan 0 archive compression scan debug
_array_cdb_view_enabled TRUE array mode enabled for CDB views
_bloom_filter_size 0 bloom filter vector size (in KB)
_bloom_predicate_offload TRUE enables or disables bloom filter predicate offload to cells
_bloom_rm_filter FALSE remove bloom predicate in favor of zonemap join pruning predicate
_bloom_sm_enabled FALSE enable bloom filter optimization using slave mapping
_cell_materialize_all_expressions FALSE Force materialization of all offloadable expressions on the cells
_cell_materialize_virtual_columns TRUE enable offload of expressions underlying virtual columns to cells
_cell_offload_complex_processing TRUE enable complex SQL processing offload to cells
_cell_offload_expressions TRUE enable offload of expressions to cells
_cell_offload_sys_context TRUE enable offload of SYS_CONTEXT evaluation to cells
_common_data_view_enabled TRUE common objects returned through dictionary views
_dbg_scan 0 generic scan debug
_fast_index_maintenance TRUE fast global index maintenance during PMOPs
_hashops_prefetch_size 4 maximum no of rows whose relevant memory locations are prefetched
_oltp_comp_dbg_scan 0 oltp compression scan debug
_optimizer_adaptive_plans TRUE enable adaptive plans
_optimizer_ads_max_table_count 0 maximum number of tables in a join under ADS
_optimizer_ads_time_limit 0 maximum time limit (seconds) under ADS
_optimizer_ads_use_result_cache TRUE use result cache for ADS queries
_optimizer_ansi_join_lateral_enhance TRUE optimization of left/full ansi-joins and lateral views
_optimizer_ansi_rearchitecture TRUE re-architecture of ANSI left, right, and full outer joins
_optimizer_batch_table_access_by_rowid TRUE enable table access by ROWID IO batching
_optimizer_cluster_by_rowid TRUE enable/disable the cluster by rowid feature
_optimizer_cluster_by_rowid_control 3 internal control for cluster by rowid feature mode
_optimizer_cube_join_enabled TRUE enable cube join
_optimizer_dsdir_usage_control 126 controls optimizer usage of dynamic sampling directives
_optimizer_gather_feedback TRUE optimizer gather feedback
_optimizer_gather_stats_on_load TRUE enable/disable online statistics gathering
_optimizer_generate_transitive_pred TRUE optimizer generate transitive predicates
_optimizer_hybrid_fpwj_enabled TRUE enable hybrid full partition-wise join when TRUE
_optimizer_multi_table_outerjoin TRUE allows multiple tables on the left of outerjoin
_optimizer_null_accepting_semijoin TRUE enables null-accepting semijoin
_optimizer_partial_join_eval TRUE partial join evaluation parameter
_optimizer_performance_feedback OFF controls the performance feedback
_optimizer_proc_rate_level BASIC control the level of processing rates
_optimizer_proc_rate_source DEFAULT control the source of processing rates
_optimizer_strans_adaptive_pruning TRUE allow adaptive pruning of star transformation bitmap trees
_optimizer_unnest_scalar_sq TRUE enables unnesting of of scalar subquery
_optimizer_use_gtt_session_stats TRUE use GTT session private statistics
_optimizer_use_histograms TRUE enable/disable the usage of histograms by the optimizer
_parallel_ctas_enabled TRUE enable/disable parallel CTAS operation
_parallel_fault_tolerance_threshold 3 total number of faults fault-tolerance will handle
_partition_advisor_srs_active TRUE enables sampling based partitioning validation
_partition_cdb_view_enabled TRUE partitioned cdb view evaluation enabled
_pred_push_cdb_view_enabled TRUE predicate pushdown enabled for CDB views
_px_adaptive_dist_method CHOOSE determines the behavior of adaptive distribution methods
_px_adaptive_dist_method_threshold 0 Buffering / decision threshold for adaptive distribution methods
_px_back_to_parallel OFF allow going back to parallel after a serial operation
_px_cdb_view_enabled TRUE parallel cdb view evaluation enabled
_px_concurrent TRUE enables pq with concurrent execution of serial inputs
_px_cpu_autodop_enabled TRUE enables or disables auto dop cpu computation
_px_cpu_process_bandwidth 200 CPU process bandwidth in MB/sec for DOP computation
_px_filter_parallelized TRUE enables or disables correlated filter parallelization
_px_filter_skew_handling TRUE enable correlated filter parallelization to handle skew
_px_groupby_pushdown FORCE perform group-by pushdown for parallel query
_px_hybrid_TSM_HWMB_load TRUE Enable Hybrid Temp Segment Merge/High Water Mark Brokered load method
_px_join_skew_handling TRUE enables skew handling for parallel joins
_px_join_skew_minfreq 30 sets minimum frequency(%) for skewed value for parallel joins
_px_join_skew_ratio 10 sets skew ratio for parallel joins
_px_load_monitor_threshold 10000 threshold for pushing information to load slave workload monitor
_px_loc_msg_cost 1000 CPU cost to send a PX message via shared memory
_px_monitor_load FALSE enable consumer load slave workload monitoring
_px_net_msg_cost 10000 CPU cost to send a PX message over the internconnect
_px_object_sampling_enabled TRUE use base object sampling when possible for range distribution
_px_parallelize_expression TRUE enables or disables expression evaluation parallelization
_px_partial_rollup_pushdown ADAPTIVE perform partial rollup pushdown for parallel execution
_px_pwmr_enabled TRUE parallel partition wise match recognize enabled
_px_replication_enabled TRUE enables or disables replication of small table scans
_px_single_server_enabled TRUE allow single-slave dfo in parallel query
_px_tq_rowhvs TRUE turn on intra-row hash valueing sharing in TQ
_px_wif_dfo_declumping CHOOSE NDV-aware DFO clumping of multiple window sorts
_px_wif_extend_distribution_keys TRUE extend TQ data redistribution keys for window functions
_rowsets_cdb_view_enabled TRUE rowsets enabled for CDB views
_rowsets_enabled TRUE enable/disable rowsets
_rowsets_max_rows 200 maximum number of rows in a rowset
_rowsets_target_maxsize 524288 target size in bytes for space reserved in the frame for a rowset
_smm_max_size_static 92160 static maximum work area size in auto mode (serial)
_smm_px_max_size_static 230400 static maximum work area size in auto mode (global)
_sql_hvshare_threshold 0 threshold to control hash value sharing across operators
_stat_aggs_one_pass_algorithm FALSE enable one pass algorithm for variance-related functions
_upddel_dba_hash_mask_bits 0 controls masking of lower order bits in DBA
_use_hidden_partitions FALSE use hidden partitions
_zonemap_control 0 control different uses/algorithms related to zonemaps
_zonemap_use_enabled TRUE enable the use of zonemaps for IO pruning
optimizer_adaptive_features TRUE controls adaptive features
optimizer_adaptive_reporting_only FALSE use reporting-only mode for adaptive optimizations
parallel_degree_level 100 adjust the computed degree in percentage
parallel_execution_message_size 16384 message buffer size for parallel execution
parallel_fault_tolerance_enabled FALSE enables or disables fault-tolerance for parallel statement

【12c新特性】12c中如何自动启动PDB Pluggable Database

PDB Pluggable Database是12c中扛鼎的一个新特性, 但是对于CDB中的PDB,默认启动CDB时不会将所有的PDB带起来,这样我们就需要手动alter pluggable database ALL OPEN;

 

 

例如:

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> 
SQL> startup ;
ORACLE instance started.

Total System Global Area 1419685888 bytes
Fixed Size                  2288344 bytes
Variable Size             536872232 bytes
Database Buffers          872415232 bytes
Redo Buffers                8110080 bytes
Database mounted.
Database opened.
SQL> select con_id,name,open_mode from v$pdbs;

    CON_ID NAME                           OPEN_MODE
---------- ------------------------------ ----------
         2 PDB$SEED                       READ ONLY
         3 MACC                           MOUNTED

 

 

 

可以通过添加Trigger的形式来客制化startup时自动将PDB OPEN:

 

 

CREATE TRIGGER open_all_pdbs
   AFTER STARTUP
   ON DATABASE
BEGIN
   EXECUTE IMMEDIATE 'alter pluggable database all open';
END open_all_pdbs;
/

Trigger created.

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> 
SQL> startup;
ORACLE instance started.

Total System Global Area 1419685888 bytes
Fixed Size                  2288344 bytes
Variable Size             536872232 bytes
Database Buffers          872415232 bytes
Redo Buffers                8110080 bytes
Database mounted.
Database opened.
SQL> select con_id,name,open_mode from v$pdbs;

    CON_ID NAME                           OPEN_MODE
---------- ------------------------------ ----------
         2 PDB$SEED                       READ ONLY
         3 MACC                           READ WRITE

NOTE: dependency between database MAC and diskgroup resource ora.DATADG.dg is established
alter pluggable database all open
Sun Jul 07 01:40:59 2013
This instance was first to open pluggable database MACC (container=3)
Opening pdb MACC (3) with no Resource Manager plan active
Pluggable database MACC opened read write
Completed: alter pluggable database all open
Starting background process CJQ0

 

 

使用SYS用户创建如下触发器即可:

 

 

conn / as sysdba

CREATE TRIGGER open_all_pdbs
   AFTER STARTUP
   ON DATABASE
BEGIN
   EXECUTE IMMEDIATE 'alter pluggable database all open';
END open_all_pdbs;
/

诡异的CBO参数_optimizer_use_histograms

_optimizer_use_histograms是一个CBO隐藏参数,目前所知该参数负责让CBO optimizer启用/禁用Histogram(This parameter enables/disables the usage of histograms by the optimizer.)

 

不过诡异的是这个参数在10gR2、12cR1中均存在,但是在11gR2中消失了。。。

 

11gR2:

SQL> select * from v$version;

BANNER
——————————————————————————–
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 – 64bit Production
PL/SQL Release 11.2.0.3.0 – Production
CORE 11.2.0.3.0 Production
TNS for Linux: Version 11.2.0.3.0 – Production
NLSRTL Version 11.2.0.3.0 – Production

SQL> alter session set “_optimizer_use_histograms”=false;
alter session set “_optimizer_use_histograms”=false
*
ERROR at line 1:
ORA-02248: invalid option for ALTER SESSION

 

12cR1:

SQL> select * from v$version;

BANNER
——————————————————————————–
CON_ID
———-
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 – 64bit Production
0

PL/SQL Release 12.1.0.1.0 – Production
0

CORE 12.1.0.1.0 Production
0
BANNER
——————————————————————————–
CON_ID
———-
TNS for Linux: Version 12.1.0.1.0 – Production
0

NLSRTL Version 12.1.0.1.0 – Production
0
SQL> alter session set “_optimizer_use_histograms”=false;

Session altered.

 

 

 

10gR2:

 

SQL> select * from v$version;

BANNER
—————————————————————-
Oracle Database 10g Enterprise Edition Release 10.2.0.5.0 – 64bi
PL/SQL Release 10.2.0.5.0 – Production
CORE 10.2.0.5.0 Production
TNS for Linux: Version 10.2.0.5.0 – Production
NLSRTL Version 10.2.0.5.0 – Production

SQL> alter session set “_optimizer_use_histograms”=false;

Session altered.

Oracle Database 12c架构图

Oracle Database 12c架构图 高清   包括最新的后台进程及其工作原理

 

12c arch

 

pluggable Database 多租户架构大图

 

pluggable database 12c arch

【Maclean Liu技术分享】12c 12.1.0.1 RAC安装教学视频 基于Vbox+Oracle Linux 5.7

【Maclean Liu技术分享】12c 12.1.0.1 RAC Real Application Cluster 安装教学视频  基于Vbox+Oracle Linux 5.7

 

安装步骤脚本下载:

Maclean技术分享 12c RAC 安装OEL 5.7 12.1.0.1 RAC VBox安装脚本.txt

 

视频观看地址:
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