Oracle 18.3 和 12.2 版本初始化参数缺省值的改变列表

从 Oracle Database 12.2 到 Oracle 18.3 ，有很多初始化参数的缺省值发生了变化，我整理了一个列表供大家参考。

这其中有些参数和硬件配置有关，但是绝大多数就是因为版本变化做出的改变。尤其是参数值的 True 和 False 的改变。

比如 _use_single_log_writer 的缺省值变成了 TRUE，意味着缺省将禁用自适应 LGWR 的特性。

KSPPINM NEWVALUE OLDVALUE KSPPDESC

------------------------------ ------------------------------ ------------------------------ ------------------------------------------------------------

_spin_count 1 2000 Amount to spin waiting for a latch

_super_shared_conversion_threshold 300 1280 conversion threshold limit for supershared mode

_num_longop_child_latches 1 8 number of child latches for long op array

_kill_session_dump FALSE TRUE Process dump on kill session immediate

_session_allocation_latches 1 8 one latch per group of sessions

_disable_highres_ticks TRUE FALSE disable high-res tick counter

_enqueue_sync_retry_attempts 15 3 max number of times the bg process to retry synchronous enqu

eue open if it failed because master could not allocate memo

ry

_enable_shared_pool_durations TRUE FALSE temporary to disable/enable kgh policy

_kse_snap_ring_size 0 100 ring buffer to debug internal error 17090

_ksi_clientlocks_enabled TRUE FALSE if TRUE, DLM-clients can provide the lock memory

_instant_file_create FALSE TRUE enable instant file creation on sparse media

_ksipc_service_mask 1 0 KSIPC Service Mask

_proc_grp_enabled 3 FALSE proc-group enabled

_ksrma_enabled off OFF turn ksrma off, make it automatic, or turn on CMI or KSMSQ p

rovider. Default is off

_hang_resolution_promote_proce TRUE FALSE Hang Management hang resolution promote process termination

ss_termination

_lm_singleton_pdb_opt TRUE FALSE RAC PDB singleton optimization

_lm_rm_object_bypass TRUE FALSE enable read-mostly object bypass for HARIM

_reconfiguration_opt_level 13 0 reconfiguration optimization level

_dlm_stats_collect_mode 4 0 DLM statistics collection mode

_lm_comm_rcv_msg_history_slots 50 0 GES communication receive message history slots

_reliable_block_sends TRUE FALSE if TRUE, no side channel on reliable interconnect

_memory_broker_shrink_heaps 15 0 memory broker allow policy to shrink shared pool

_dbwr_nowrite_assert_interval 7200 0 dbwriter assert interval after no write seconds

_db_block_vlm_check FALSE TRUE check for mapping leaks (debugging only)

_db_cache_miss_check_les FALSE TRUE check LEs after cache miss

_db_cache_mman_latch_check FALSE TRUE check for wait latch get under MMAN ops in kcb

_db_block_chunkify_ncmbr FALSE TRUE chunkify noncontig multi block reads

_db_cache_wait_debug 0 1 trace new kslwaits

_db_block_iterations_for_rm 2000 20 number of blocks to reduce every iteration for RM

_db_dump_from_disk_and_efc 0 2 dump contents from disk and efc

_assert_encrypted_tablespace_blocks TRUE FALSE if TRUE, assert encrypted tablespace blocks must be encrypted

_high_intrinsic_scn_growth_alert 1440 60 high intrinsic SCN growth rate alert time in minutes

compatible 18.0.0 12.2.0.0.0 Database will be completely compatible with this software ve

rsion

_num_rlslaves 2 16 number of rl slaves to clear orls

_use_single_log_writer TRUE ADAPTIVE Use a single process for redo log writing

_max_pending_scn_bcasts 8 9 maximum number of pending SCN broadcasts

_gc_trace_freelist_empty FALSE TRUE if TRUE, dump a trace when we run out of lock elements

_auto_export_preplugin_backup TRUE FALSE auto export pre-plugin backup

_time_based_rcv_ckpt_target 180 0 time-based incremental recovery checkpoint target in sec

_time_based_rcv_hdr_update_int 180 0 time-based incremental recovery file header update interval

erval in sec

_nologging_sendbuf_ratio 90 99 Nologging standby: outstanding send buffer ratio

_nologging_sdcl_append_wait 200 100 Nologging standby append sdcl wait time

_shadow_lost_write_found 118 22 Specify shadow lost write error handling

_imtxn_table_enable TRUE FALSE is In-Memory Txn Table cache enabled

_compression_compatibility 18.0.0 12.2.0.0.0 Compression compatibility

_dbg_scan 0 2048 generic scan debug

_inmemory_subcusize 512 0 In-memory subCU size

_inmemory_fsdw_schedlrtm 1 10 in-memory faststart defer write scheduler cycle (sec)

_inmemory_repopulate_disable 2 FALSE disable In-memory repopulate

_inmemory_repopulate_flags 2 0 In-memory repopulate decision flags

_inmemory_dynamic_scans AUTO DISABLE Enable IM Dynamic Scans

_imado_optimize_period 0 20 IM-store optimize period for AIM (in minutes)

_kql_clientlocks_enabled 15 1 clients allocating DLM memory

_pdb_service_on_root_listener FALSE TRUE pdb services on CDB ROOT listeners

_cursor_db_buffers_pinned 76 2 additional number of buffers a cursor can pin at once

_qesma_mvob_lru_sz 25 0 size of MVOB LRU list for QESMA session cache

_qesma_bo_lru_sz 25 0 size of base object LRU list for QESMA session cache

optimizer_features_enable 18.1.0 12.2.0.1 optimizer plan compatibility parameter

audit_trail DB NONE enable system auditing

_optimizer_undo_cost_change 18.1.0 12.2.0.1 optimizer undo cost change

parallel_threads_per_cpu 1 2 number of parallel execution threads per CPU

_parallel_adaptive_max_users 4 2 maximum number of users running with default DOP

_qa_lrg_type 0 1 Oracle internal parameter to specify QA lrg type

_bloom_folding_min 0 128 bloom filter folding size lower bound (in KB)

_smm_isort_cap 102400 0 maximum work area for insertion sort(v1)

_sqlmon_max_plan 20 160 Maximum number of plans entry that can be monitored. Default

s to 20 per CPU

parallel_servers_target 20 64 instance target in terms of number of parallel servers

_px_chunklist_count_ratio 32 8 ratio of the number of chunk lists to the default DOP per in

stance

_emon_outbound_connect_timeout 7200000 30000 timeout for completing connection set up to clients

_emon_send_timeout 7200000 10000 send timeout after which the client is unregistered

_aq_pt_processes 10 15 Partition background processes

_asm_disable_proact_client_cle FALSE TRUE disable proactive client cleanup

anup

_asm_disable_patch_compat FALSE TRUE disable DG patch compatibility checks

_asm_allow_prepare_split TRUE FALSE Allow database prepare and split in non-appliance mode

target_pdbs 1 2 Parameter is a hint to adjust certain attributes of the CDB

max_pdbs 254 4098 max number of pdbs allowed in CDB or Application ROOT

_cdb_disable_pdb_limit FALSE TRUE CDB Compatible

_cdb_special_old_xplan TRUE FALSE display old-style plan for CDB special fixed table

_upgrade_optim TRUE FALSE Upgrade optimization enabled

_upgrade_capture_noops TRUE FALSE do not skip capturing noops during upgrade

_enable_containers_subquery TRUE FALSE enable transformation to containers() sub query

供大家参考了。

By eygle on 2018-08-02 08:56 |

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