디비가이

크리에이티브 커먼즈 라이선스

이 저작물은 크리에이티브 커먼즈 코리아 저작자표시-비영리-동일조건변경허락 2.0 대한민국 라이선스에 따라 이용하실 수 있습니다.

10000 control file debug event, name 'control_file'
10001 control file crash event1
10002 control file crash event2
10003 control file crash event3
10004 control file crash event4
10005 trace latch operations for debugging
10006 testing - block recovery forced
10007 log switch debug crash after new log select, thread %s
10008 log switch debug crash after new log header write, thread %s
10009 log switch debug crash after old log header write, thread %s
10010 Begin Transaction
10011 End Transaction
10012 Abort Transaction
10013 Instance Recovery
10014 Roll Back to Save Point
10015 Undo Segment Recovery
10016 Undo Segment extend
10017 Undo Segment Wrap
10018 Data Segment Create
10019 Data Segment Recovery
10020 partial link restored to linked list (KSG)
10021 latch cleanup for state objects (KSS)
10022 trace ktsgsp
10023 Create Save Undo Segment
10024 Write to Save Undo
10025 Extend Save Undo Segment
10026 Apply Save Undo
10027 latch cleanup for enqueue locks (KSQ)
10028 latch cleanup for enqueue resources (KSQ)
10029 session logon (KSU)
10030 session logoff (KSU)
10031 row source debug event (R*)
10032 sort end (SOR*)
10035 parse SQL statement (OPIPRS)
10036 create remote row source (QKANET)
10037 allocate remote row source (QKARWS)
10038 dump row source tree (QBADRV)
10039 type checking (OPITCA)
10040 dirty cache list
10041 dump undo records skipped
10042 trap error during undo application
10044 free list undo operations
10045 "free list update operations - ktsrsp, ktsunl"
10046 enable SQL statement timing
10047 trace switching of sessions
10048 Undo segment shrink
10049 protect library cache memory heaps
10050 sniper trace
10051 trace OPI calls
10052 don't clean up obj$
10053 CBO Enable optimizer trace
10054 trace UNDO handling in MLS
10055 trace UNDO handing
10056 dump analyze stats (kdg)
10057 suppress file names in error messages
10058 use table scan cost in tab$.spare1
10060 CBO Enable predicate dump
10061 disable SMON from cleaning temp segment
10062 disable usage of OS Roles in osds
10063 disable usage of DBA and OPER privileges in osds
10064 "thread enable debug crash level %s, thread %s"
10065 limit library cache dump information for state object dump
10066 simulate failure to verify file
10067 force redo log checksum errors - block number
10068 force redo log checksum errors - file number
10069 Trusted Oracle test event
10070 force datafile checksum errors - block number
10071 force datafile checksum errors - file number
10072 protect latch recovery memory
10073 have PMON dump info before latch cleanup
10074 default trace function mask for kst
10075 CBO Disable outer-join to regular join conversion
10076 CBO Enable cartesian product join costing
10077 CBO Disable view-merging optimization for outer-joins
10078 CBO Disable constant predicate elimination optimization
10080 dump a block on a segment list which cannot be exchanged
10081 segment High Water Mark has been advanced
10082 free list head block is the same as the last block
10083 a brand new block has been requested from space management
10084 free list becomes empty
10085 free lists have been merged
10086 CBO Enable error if kko and qka disagree on oby sort
10087 disable repair of media corrupt data blocks
10088 CBO Disable new NOT IN optimization
10089 CBO Disable index sorting
10090 invoke other events before crash recovery
10091 CBO Disable constant predicate merging
10092 CBO Disable hash join
10093 CBO Enable force hash joins
10094 before resizing a data file
10095 dump debugger commands to trace file
10096 after the cross instance call when resizing a data file
10097 after generating redo when resizing a data file
10098 after the OS has increased the size of a data file
10099 after updating the file header with the new file size
10100 after the OS has decreased the size of a data file
10101 atomic redo write recovery
10102 switch off anti-joins
10103 CBO Disable hash join swapping
10104 dump hash join statistics to trace file
10105 CBO Enable constant pred trans and MPs w WHERE-clause
10106 CBO Disable evaluating correlation pred last for NOT IN
10107 CBO Always use bitmap index
10108 CBO Don't use bitmap index
10109 CBO Disable move of negated predicates
10110 CBO Try index rowid range scans
10111 Bitmap index creation switch
10112 Bitmap index creation switch
10113 Bitmap index creation switch
10114 Bitmap index creation switch
10115 CBO Bitmap optimization use maximal expression
10116 CBO Bitmap optimization switch
10117 CBO Disable new parallel cost model
10118 CBO Enable hash join costing
10119 QKA Disable GBY sort elimination
10120 CBO Disable index fast full scan
10121 CBO Don't sort bitmap chains
10122 CBO disable count(col) => count(*) transformation
10123 QKA Disable Bitmap And-EQuals
10145 test auditing network errors
10146 enable Oracle TRACE collection
10200 block cleanout
10201 consistent read undo application
10202 consistent read block header
10203 consistent read buffer status
10204 signal recursive extend
10205 row cache debugging
10206 transaction table consistent read
10207 consistent read transactions' status report
10208 consistent read loop check
10209 enable simulated error on control file
10210 check data block integrity
10211 check index block integrity
10212 check cluster integrity
10213 crash after control file write
10214 simulate write errors on control file
10215 simulate read errors on control file
10216 dump control file header
10217 debug sequence numbers
10218 dump uba of applied undo
10219 monitor multi-pass row locking
10220 show updates to the transaction table
10221 show changes done with undo
10222 row cache
10223 transaction layer - turn on verification codes
10226 trace CR applications of undo for data operations
10227 verify (multi-piece) row structure
10228 trace application of redo by kcocbk
10230 check redo generation by copying before applying
10231 skip corrupted blocks on _table_scans_
10232 dump corrupted blocks symbolically when kcbgotten
10233 skip corrupted blocks on index operations
10234 trigger event after calling kcrapc to do redo N times
10235 check memory manager internal structures
10236 library cache manager
10237 simulate ^C (for testing purposes)
10238 instantiation manager
10239 multi-instance library cache manager
10240 dump dba's of blocks that we wait for
10241 dump SQL generated for remote execution (OPIX)
10243 simulated error for test %s of K2GTAB latch cleanup
10244 make tranids in error msgs print as 0.0.0 (for testing)
10245 simulate lock conflict error for testing PMON
10246 print trace of PMON actions to trace file
10247 Turn on scgcmn tracing. (VMS ONLY)
10248 turn on tracing for dispatchers
10249 turn on tracing for multi-stated servers
10250 Trace all allocate and free calls to the topmost SGA heap
10251 check consistency of transaction table and undo block
10252 simulate write error to data file header
10253 simulate write error to redo log
10254 trace cross-instance calls
10256 turn off multi-threaded server load balancing
10257 trace multi-threaded server load balancing
10258 force shared servers to be chosen round-robin
10259 get error message text from remote using explicit call
10260 Trace calls to SMPRSET (VMS ONLY)
10261 Limit the size of the PGA heap
10262 Don't check for memory leaks
10263 Don't free empty PGA heap extents
10264 Collect statistics on context area usage (x$ksmcx)
10265 Keep random system generated output out of error messages
10266 Trace OSD stack usage
10267 Inhibit KSEDMP for testing
10268 Don't do forward coalesce when deleting extents
10269 Don't do coalesces of free space in SMON
10270 Debug shared cursors
10271 distributed transaction after COLLECT
10272 distributed transaction before PREPARE
10273 distributed transaction after PREPARE
10274 distributed transaction before COMMIT
10275 distributed transaction after COMMIT
10276 distributed transaction before FORGET
10277 Cursor sharing (or not) related event (used for testing)
10281 maximum time to wait for process creation
10282 Inhibit signalling of other backgrounds when one dies
10286 Simulate control file open error
10287 Simulate archiver error
10288 Do not check block type in ktrget
10289 Do block dumps to trace file in hex rather than fromatted
10290 kdnchk - checkvalid event - not for general purpose use.
10291 die in dtsdrv to test controlfile undo"
10292 dump uet entries on a 1561 from dtsdrv"
10293 dump debugging information when doing block recovery"
10294 enable PERSISTENT DLM operations on non-compliant systems"
10300 disable undo compatibility check at database open
10301 Enable LCK timeout table consistency check"
10320 Enable data layer (kdtgrs) tracing of space management calls"
10352 report direct path statistics
10353 number of slots
10354 turn on direct read path for parallel query
10355 turn on direct read path for scans
10356 turn on hint usage for direct read
10357 turn on debug information for direct path
10374 parallel query server interrupt (validate lock value)
10375 turn on checks for statistics rollups
10376 turn on table queue statistics
10377 turn off load balancing
10379 direct read for rowid range scans (unimplemented)
10380 kxfp latch cleanup testing event
10381 kxfp latch cleanup testing event
10382 parallel query server interrupt (reset)
10383 auto parallelization testing event
10384 parallel dataflow scheduler tracing
10385 parallel table scan range sampling method
10386 parallel SQL hash and range statistics
10387 parallel query server interrupt (normal)
10388 parallel query server interrupt (failure)
10389 parallel query server interrupt (cleanup)
10390 Trace parallel query slave execution
10391 trace rowid range partitioning
10392 parallel query debugging bits
10393 print parallel query statistics
10394 allow parallelization of small tables
10395 adjust sample size for range table queues
10396 circumvent range table queues for queries
10397 suppress verbose parallel coordinator error reporting
10398 enable timeouts in parallel query threads
10399 use different internal maximum buffer size
10400 turn on system state dumps for shutdown debugging
10500 turn on traces for SMON
10510 turn off SMON check to offline pending offline rollbacksegment
10511 turn off SMON check to cleanup undo dictionary
10512 turn off SMON check to shrink rollback segments
10600 check cursor frame allocation
10602 cause an access violation (for testing purposes)
10603 cause an error to occur during truncate (for testing purposes)
10604 trace parallel create index
10605 enable parallel create index by default
10606 trace parallel create index
10607 trace index rowid partition scan
10608 trace create bitmap index
10610 trace create index pseudo optimizer
10666 Do not get database enqueue name
10667 Cause sppst to check for valid process ids
10690 Set shadow process core file dump type (Unix only)
10691 Set background process core file type (Unix only)
10700 Alter access violation exception handler
10701 Dump direct loader index keys
10702 Enable histogram data generation
10703 Simulate process death during enqueue get
10704 Print out information about what enqueues are being obtained
10706 Print out information about instance lock manipulation
10707 Simulate process death for instance registration
10708 Print out Tracing information for skxf multi instance comms
10709 enable parallel instances in create index by default
10710 trace bitmap index access
10711 trace bitmap index merge
10712 trace bitmap index or
10713 trace bitmap index and
10714 trace bitmap index minus
10715 trace bitmap index conversion to rowids
10800 disable Smart Disk scan
10801 enable Smart Disk trace
10802 reserved for Smart Disk
10803 write timing statistics on OPS recovery scan
10804 reserved for ksxb
10805 reserved for row source sort
10900 extent manager fault insertion event #%s
10924 import storage parse error ignore event
10925 trace name context forever
10926 trace name context forever
10927 trace name context forever
10928 trace name context forever
10999 do not get database enqueue name

크리에이티브 커먼즈 라이선스

이 저작물은 크리에이티브 커먼즈 코리아 저작자표시-비영리-동일조건변경허락 2.0 대한민국 라이선스에 따라 이용하실 수 있습니다.

** 9i 부터 block prefetch 기법(?)이 나왔는데 10g 까지는 사용자가 컨트롤 할수 없었다.
만약에 테이블의 클러스터 팩터가 안좋다면은 미리 블록을 읽어도 소용이 없기때문에 block prefetch가 발생할까라는 의문이 들어서 테스트

 

db file scattered read가 나오면 block prefetch가 됨

The event db file scattered read is associated with multiblock physical reads. Therefore,
if it occurs for rowid accesses or index range scans, it means that block prefetching
is being used.

 

--> 결론은 클러스터링 팩터가 안좋아도 block prefetch 하네요.

 

drop table t1 purge;

CREATE TABLE t1 (
  id NUMBER NOT NULL,
  n NUMBER,
  pad VARCHAR2(4000),
  CONSTRAINT t1_pk PRIMARY KEY(id)
)
PCTFREE 99 PCTUSED 1;

drop table t2 purge;

CREATE TABLE t2 (
  id NUMBER NOT NULL,
  t1_id NUMBER NOT NULL,
  n NUMBER,
  pad VARCHAR2(4000),
  CONSTRAINT t2_pk PRIMARY KEY(id)
) 
PCTFREE 99 PCTUSED 1;

INSERT INTO t1 SELECT rownum, rownum, dbms_random.string('p',50) FROM dual CONNECT BY level <= 1000 ORDER BY dbms_random.random;
INSERT INTO t2 SELECT rownum, rownum, rownum, dbms_random.string('p',50) FROM dual CONNECT BY level <= 1000 ORDER BY dbms_random.random;

commit;

--> 데이터 생성시 클러스터링 팩터를 안좋게 하기 위해서 dbms_random.random을 사용.

 

BEGIN
  dbms_stats.gather_table_stats(user,'t1');
  dbms_stats.gather_table_stats(user,'t2');
END;
/

 

06:02:34 SQL> select count(*) from t2;

  COUNT(*)
----------
       1000
      
06:04:00 SQL> select count(*) from t1;

  COUNT(*)
----------
        1000
       

EXPLAIN PLAN FOR
SELECT /*+ leading(t1) use_nl(t2) index(t1) index(t2) */ *
FROM t1, t2
WHERE t1.id = t2.t1_id
AND t1.n = 19;

SELECT * FROM table(dbms_xplan.display);

-------------------------------------------------------------------------------
| Id  | Operation                     | Name     | Rows  | Bytes | Cost (%CPU)|
-------------------------------------------------------------------------------
|   0 | SELECT STATEMENT              |          |    10 |  1180 |    21   (0)|
|   1 |  TABLE ACCESS BY INDEX ROWID  | T2       |    10 |   610 |    10   (0)|
|   2 |   NESTED LOOPS                |          |    10 |  1180 |    21   (0)|
|*  3 |    TABLE ACCESS BY INDEX ROWID| T1       |     1 |    57 |    11   (0)|
|   4 |     INDEX FULL SCAN           | T1_PK    |    10 |       |     1   (0)|
|*  5 |    INDEX RANGE SCAN           | T2_T1_ID |    10 |       |     0   (0)|
-------------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   3 - filter("T1"."N"=19)
   5 - access("T1"."ID"="T2"."T1_ID")
  

테이블 통계정보

TABLE_NAME                    : T1
NUM_ROWS                      : 1000
BLOCKS                        : 1000
SAMPLE_SIZE                   : 1000
LAST_ANAL                     : 2009/04/16 06:44:57

 

TABLE_NAME                    : T2
NUM_ROWS                      : 1000
BLOCKS                        : 1000
SAMPLE_SIZE                   : 1000
LAST_ANAL                     : 2009/04/16 06:44:57
      

인덱스 통계정보  
TABLE_NAME                    : T1
INDEX_NAME                    : T1_PK
BLEVEL                        : 1
LEAF_BLOCKS                   : 2
DISTINCT_KEYS                 : 1000
CLUSTERING_FACTOR             : 1000
SAMPLE_SIZE                   : 1000
LAST_ANAL                     : 2009/04/16 06:44:57

 

TABLE_NAME                    : T2
INDEX_NAME                    : T2_PK
BLEVEL                        : 1
LEAF_BLOCKS                   : 2
DISTINCT_KEYS                 : 1000
CLUSTERING_FACTOR             : 1000
SAMPLE_SIZE                   : 1000
LAST_ANAL                     : 2009/04/16 06:44:57

10046 트레이스 내용

SELECT /*+ leading(t1) use_nl(t2) index(t1) index(t2) */ *
FROM t1, t2
WHERE t1.id = t2.t1_id
AND t1.n = 19

call     count       cpu    elapsed       disk      query    current        rows
------- ------  -------- ---------- ---------- ---------- ----------  ----------
Parse        1      0.04       0.03          0          0          0           0
Execute      1      0.00       0.00          0          0          0           0
Fetch        2      0.26       0.31       2054       2008          0           1
------- ------  -------- ---------- ---------- ---------- ----------  ----------
total        4      0.30       0.35       2054       2008          0           1

Misses in library cache during parse: 1
Optimizer mode: ALL_ROWS
Parsing user id: 28  (LP)

Rows     Row Source Operation
-------  ---------------------------------------------------
      1  TABLE ACCESS BY INDEX ROWID T2 (cr=2008 pr=2054 pw=0 time=87815 us)
   1002   NESTED LOOPS  (cr=1008 pr=1040 pw=0 time=8315357 us)
      1    TABLE ACCESS BY INDEX ROWID T1 (cr=1004 pr=1032 pw=0 time=92635 us)
   1000     INDEX FULL SCAN T1_PK (cr=4 pr=8 pw=0 time=3969 us)(object id 13424)
   1000    INDEX FULL SCAN T2_PK (cr=4 pr=8 pw=0 time=45298 us)(object id 13426)

Rows     Execution Plan
-------  ---------------------------------------------------
      0  SELECT STATEMENT   MODE: ALL_ROWS
      1   TABLE ACCESS   MODE: ANALYZED (BY INDEX ROWID) OF 'T2' (TABLE)
   1002    NESTED LOOPS
      1     TABLE ACCESS   MODE: ANALYZED (BY INDEX ROWID) OF 'T1' (TABLE)
   1000      INDEX   MODE: ANALYZED (FULL SCAN) OF 'T1_PK' (INDEX (UNIQUE))
   1000     INDEX   MODE: ANALYZED (FULL SCAN) OF 'T2_PK' (INDEX (UNIQUE))

Elapsed times include waiting on following events:
  Event waited on                             Times   Max. Wait  Total Waited
  ----------------------------------------   Waited  ----------  ------------
  SQL*Net message to client                       2        0.00          0.00
  db file scattered read                        228        0.03          0.21
  db file sequential read                        49        0.00          0.00
  SQL*Net message from client                     2        0.00          0.00
  db file parallel read                          96        0.00          0.03
********************************************************************************

 

앗.. 그런데 울트라 에디터에서는 컬럼모드로 보면은 실행계획 잘 나온던데.. 붙이면 이상하게 나오네요.. 이거 어떻게 해야지 잘 나오나요?

크리에이티브 커먼즈 라이선스

이 저작물은 크리에이티브 커먼즈 코리아 저작자표시-비영리-동일조건변경허락 2.0 대한민국 라이선스에 따라 이용하실 수 있습니다.

간간이 궁금한점이 있을때 조동욱님에게 멜 보내서 조언을 들었는데 그게 이제 공식적으로 가능해졌당..

정보는 계속 공유되어서 약간의 경험과 감을 빼면은 열심히 하면은 능력이 차이가 점점 좁아지지 않을까 생각이 든다.
하지만 공유가 되어도 좀혀지지 않는 그 무언가가 있지..

열심히 해야 겠구만..

엔지어분들이랑 이야기 하다 보면은 문제가 생겼을 os, 네트워크, 스토리지, DB 엔지어들이 책임을 서로 미룬다고 하는데 심지어 로그까지 지워버려서..

이때 모르면 지는거고 덤태기 쓰는건데..

앞으로는 OS, 네트워크, DB, 개발까지 전부 알아야지 살아남는게 아닌지