"오라클 히든 파라미터"의 두 판 사이의 차이

1 _optim_peek_user_binds[편집]

alter system set "_optim_peek_user_binds" = false scope=both;

. Bind variable peeking(바인드변수 엿보기) 기능 활서 여부
. Bind Peeking : Bind 변수를 포함하는 SQL문이 최초로 실행될 때 Bind 변수값을 이용해서 실행계획을 수립하는 기능
=> Bind Peeking에 따른 잘못된 실행계획이 수립되는 것을 방지하기 위해 false 로 설정 권고

2 _optimizer_use_feedback[편집]

. 쿼리의 최초 실행 시 예측 건수와 실제 건수의 차이가 크면 opt_estimate 힌트의 형태로 쿼리가 변경되도록 함
=> 의도되지 않은 SQL 실행계획 유발의 우려가 있으므로 false로 설정 권고 

3 _add_col_optim_enabled[편집]

. column add 시 dictionary만 update 하고 이후 insert 시 해당 컬럼이 생성
=> 권고: wrong result scale로 인해 false(참고 : 19183343.8)

4 _optimizer_aggr_groupby_elim[편집]

. group-by and aggregation elimination 기능의 활성화 여부
=> 권고 : wrong result 발생으로 false(참고 : 19567916.8, 1924440.1)

5 _optimizer_reduce_groupby_key[편집]

. Group by key reduction
=> 권고 : wrong result 발생으로 false(참고 : 19567916.8, 1924440.1)

6 _add_col_optim_enabled[편집]

Allows new add column optimization FALSE 설정 Def. = TRUE

7 _b_tree_bitmap_plans[편집]

enable the use of bitmap plans for tables w. only B-tree indexes FALSE 설정 Def. = TRUE

8 _cleanup_rollback_entries[편집]

no. of undo entries to apply per transaction cleanup 2000 설정

Def. = 100

9 _clusterwide_global_transactions[편집]

enable/disable clusterwide global transactions FALSE 설정 Def. = TRUE

10 _complex_view_merging[편집]

enable complex view merging FALSE 설정 Def. = TRUE

11 _datafile_write_errors_crash_inst[편집]

ance datafile write errors always crash instance FALSE 설정 Def. = TRUE

12 _db_mttr_advice[편집]

MTTR advisory OFF 설정 Def. = ON

13 _diag_daemon[편집]

start DIAG daemon FALSE 설정 Def. = TRUE

14 _dump_rcvr_ipc[편집]

if TRUE enables IPC dump at instance eviction time FALSE 설정 Def. = TRUE

15 _enable_minscn_cr[편집]

1. enable/disable minscn optimization for CR

FALSE 설정 Def. = TRUE

16 _gc_maximum_bids[편집]

maximum number of bids which can be prepared 4 설정 Def. = 0

17 _gc_policy_time[편집]

how often to make object policy decisions in minutes 0 설정 Def. = 10

18 _gc_undo_affinity[편집]

if TRUE, enable dynamic undo affinity FALSE 설정 Def. = TRUE

19 _in_memory_undo[편집]

Make in memory undo for top level transactions FALSE 설정 Def. = TRUE

20 _kgl_large_heap_warning_thresh[편집]

old maximum heap size before KGL writes warnings to the alert log 33554432 설정

21 _library_cache_advice[편집]

whether KGL advice should be turned on FALSE 설정 Def. = TRUE

22 _memory_imm_mode_without_a[편집]

utosga Allow immediate mode without sga/memory target FALSE 설정 Def. = TRUE

23 _nlj_batching_enabled[편집]

enable batching of the RHS IO in NLJ 0 설정 Def. = 1

24 _nlj_batching_misses_enabled[편집]

enable exceptions for buffer cache misses 0 설정 Def. = 1

25 _optimizer_adaptive_cursor_sharing[편집]

optimizer adaptive cursor sharing FALSE 설정 Def. = TRUE

26 _optimizer_extended_cursor_sharing[편집]

optimizer extended cursor sharing NONE 설정 Def. = UDO

27 _optimizer_extended_cursor_shar[편집]

ing_rel optimizer extended cursor sharing for relational operators NONE 설정 Def. = SIMPLE

28 _optimizer_reduce_groupby_key[편집]

group-by key reduction FALSE 설정 Def. = TRUE

29 _optimizer_use_feedback[편집]

optimizer use feedback FALSE 설정 Def. = TRUE

30 _PX_use_large_pool[편집]

Use Large Pool as source of PX buffers TRUE 설정 Def. = FALSE

31 _row_cache_cursors[편집]

number of cached cursors for row cache management 1000 설정

Def. = 20

32 _smm_advice_enabled[편집]

if TRUE, enable v$pga_advice FALSE 설정 Def. = TRUE

33 _trace_files_public[편집]

Create publicly accessible trace files TRUE 설정 Def. = FALSE

34 _undo_autotune[편집]

enable auto tuning of undo_retention FALSE설정 Def. = TRUE

35 오라클 히든 파라메터 조회[편집]

--
-- List all hidden database parameters.
--
 
SET PAUSE ON
SET PAUSE 'Press Return to Continue'
SET PAGESIZE 60
SET LINESIZE 300
 
COLUMN ksppinm FORMAT A50
COLUMN ksppstvl FORMAT A50
 
SELECT
  ksppinm,
  ksppstvl
FROM
  x$ksppi a,
  x$ksppsv b
WHERE
  a.indx=b.indx 
AND
  substr(ksppinm,1,1) = '_'
ORDER BY ksppinm
/


-- SYS 로 Login:

select a.ksppinm name, b.ksppstvl value
from 
  x$ksppi a,
  x$ksppsv b
WHERE
  a.indx=b.indx 
and a.ksppinm like '%bloom%';