case study

Hotsos Symposium 2005 - The Basics of an Effective Test Environment 1 / 72

March 04, 2005 case study.txt

SQL> @hstats tName Null? Type----------------------------------------- -------- ----------------------------PKEY NOT NULL NUMBERSTATUS NUMBERFLAG CHAR(1)

==========================================================================================Table Statistics==========================================================================================TABLE_NAME : TLAST_ANALYZED : 04-MAR-2005 11:53:17DEGREE : 1PARTITIONED : NONUM_ROWS : 100000CHAIN_CNT : 0BLOCKS : 207EMPTY_BLOCKS : 48AVG_SPACE : 934AVG_ROW_LEN : 13MONITORING : NOSAMPLE_SIZE : 100000-----------------==========================================================================================Column Statistics==========================================================================================Name Analyzed Null? NDV Density # Nulls # Buckets Sample Avg Col Len==========================================================================================PKEY 03/04/2005 NOT NULL 100000 .000010 0 1 100000 4STATUS 03/04/2005 3 .333333 0 1 100000 2FLAG 03/04/2005 2 .500000 0 1 100000 1==========================================================================================Index Information==========================================================================================INDEX_NAME : SYS_C002345INDEX_TYPE : NORMLAST_ANALYZED : 04-MAR-2005 11:53:17DEGREE : 1PARTITIONED : NOBLEVEL : 1LEAF_BLOCKS : 187DISTINCT_KEYS : 100000AVG_LEAF_BLOCKS_PER_KEY : 1AVG_DATA_BLOCKS_PER_KEY : 1CLUSTERING_FACTOR : 204BLOCKS_IN_TABLE : 207ROWS_IN_TABLE : 100000



-----------------INDEX_NAME : T_N1INDEX_TYPE : NORMLAST_ANALYZED : 04-MAR-2005 11:53:17DEGREE : 1PARTITIONED : NOBLEVEL : 1LEAF_BLOCKS : 238DISTINCT_KEYS : 3AVG_LEAF_BLOCKS_PER_KEY : 79AVG_DATA_BLOCKS_PER_KEY : 68CLUSTERING_FACTOR : 204BLOCKS_IN_TABLE : 207ROWS_IN_TABLE : 100000-----------------INDEX_NAME : T_N2INDEX_TYPE : NORMLAST_ANALYZED : 04-MAR-2005 11:53:17DEGREE : 1PARTITIONED : NOBLEVEL : 1LEAF_BLOCKS : 293DISTINCT_KEYS : 2AVG_LEAF_BLOCKS_PER_KEY : 146AVG_DATA_BLOCKS_PER_KEY : 204CLUSTERING_FACTOR : 408BLOCKS_IN_TABLE : 207ROWS_IN_TABLE : 100000-----------------INDEX_NAME : T_N3INDEX_TYPE : NORMLAST_ANALYZED : 04-MAR-2005 11:53:17DEGREE : 1PARTITIONED : NOBLEVEL : 1LEAF_BLOCKS : 355DISTINCT_KEYS : 6AVG_LEAF_BLOCKS_PER_KEY : 59AVG_DATA_BLOCKS_PER_KEY : 68CLUSTERING_FACTOR : 410BLOCKS_IN_TABLE : 207ROWS_IN_TABLE : 100000-----------------==========================================================================================Index Columns Information==========================================================================================Index Name Pos# Order Column Name Expression==========================================================================================



SYS_C002345 1 ASC PKEYT_N1 1 ASC STATUST_N2 1 ASC FLAGT_N3 1 ASC STATUS

2 ASC FLAGSQL>SQL>SQL>SQL> @hstats flagsName Null? Type----------------------------------------- -------- ----------------------------FLAG NOT NULL CHAR(1)

==========================================================================================Table Statistics==========================================================================================TABLE_NAME : FLAGSLAST_ANALYZED : 04-MAR-2005 10:58:41DEGREE : 1PARTITIONED : NONUM_ROWS : 5CHAIN_CNT : 0BLOCKS :EMPTY_BLOCKS :AVG_SPACE :AVG_ROW_LEN : 4MONITORING : NOSAMPLE_SIZE : 5-----------------==========================================================================================Column Statistics==========================================================================================Name Analyzed Null? NDV Density # Nulls # Buckets Sample Avg Col Len==========================================================================================FLAG 03/04/2005 NOT NULL 5 .200000 0 1 5 1==========================================================================================Index Information==========================================================================================INDEX_NAME : SYS_IOT_TOP_29235INDEX_TYPE : IOTLAST_ANALYZED : 04-MAR-2005 10:58:41DEGREE : 1PARTITIONED : NO



BLEVEL : 0LEAF_BLOCKS : 1DISTINCT_KEYS : 5AVG_LEAF_BLOCKS_PER_KEY : 1AVG_DATA_BLOCKS_PER_KEY : 1CLUSTERING_FACTOR : 0BLOCKS_IN_TABLE :ROWS_IN_TABLE : 5-----------------==========================================================================================Index Columns Information==========================================================================================Index Name Pos# Order Column Name Expression==========================================================================================SYS_IOT_TOP_29235 1 ASC FLAG

SQL> @hix tIndex Flags Height Column Name------------------------------ ------- ------ ------------------------------SYS_C002345 U 2 PKEYT_N1 2 STATUST_N2 2 FLAGT_N3 2 STATUS. FLAGSQL>SQL> @hix flagsIndex Flags Height Column Name------------------------------ ------- ------ ------------------------------SYS_IOT_TOP_29235 U 1 FLAGSQL>SQL> @hcons tType Constraint # Column Constraint Rule Refers To----------- ----------------------- -- ---------- ---------------------- ---------------Primary Key T.SYS_C002345 1 PKEY

SQL> @hcons flagsType Constraint # Column Constraint Rule Refers To----------- ----------------------- -- ---------- ---------------------- ---------------Primary Key FLAGS.SYS_IOT_TOP_29235 1 FLAG

SQL> get test



1 update t2 set flag='B'3* where status=2

SQL>SQL>SQL> @hdsTableOwner[OP] :TableName : tColumnList : flag, statusWhereClause:PageSize[30] :Table blocks below hwm Table rows

(B) (R)---------------------- ----------------

208 100,000More:

Block selectivity Block count Row selectivity Row countF STATUS (pb = b/B) (b) (pr = r/R) (r)- ---------- ----------------- -------------- ----------------- ----------------A 2 79.81% 166 1.60% 1,600B 2 79.81% 166 78.40% 78,400A 1 10.58% 22 0.20% 200B 1 10.58% 22 9.80% 9,800A 0 8.65% 18 0.20% 200B 0 8.65% 18 9.80% 9,800SQL>SQL>SQL>SQL> select count(*) from t where status = '2' ;

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

800001 row selected.SQL>SQL> select count(*) from t where status = '2' and flag = 'B' ;

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

784001 row selected.SQL>



SQL>SQL> @dodmlEnter .sql file name (without extension): testEnter the workspace name: updateEnter the scenario name: problemDisplay results of SQL (ON/OFF)?: offCapturing statistics information...=================================================================Name of 10046 trace file: hotsos_ora_3364.trc=================================================================Explain Plan for Scenario update:problem

--------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |--------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 33333 | 99999 | 22 || 1 | UPDATE | T | | | ||* 2 | TABLE ACCESS FULL | T | 33333 | 99999 | 22 |--------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

2 - filter("T"."STATUS"=2)Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_1988.trc=================================================================

Actual Plan for Scenario update:problemSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=563 r=651 w=0 time=5998399 us)'STAT #1 id=2 cnt=80000 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=200 w=0 time=480438 us)'SQL>SQL>SQL> @lsscstatList of values (Workspace)------------------------------------------------------------UPDATEWorkspace []: update



List of values (Scenario)------------------------------------------------------------PROBLEMScenario []: problem

Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 10cache buffer handles L 54channel operations parent latch L 4checkpoint queue latch L 6,935child cursor hash table L 15Consistent RBA L 66dml lock allocation L 7FIB s.o chain latch L 4FOB s.o list latch L 4hash table column usage latch L 4lgwr LWN SCN L 66library cache pin allocation L 90list of block allocation L 7messages L 258mostly latch-free SCN L 66multiblock read objects L 48post/wait queue L 38redo writing L 216session allocation L 2session idle bit L 17session timer L 2sim partition latch L 20simulator hash latch L 5,867simulator lru latch L 206SQL memory manager latch L 2SQL memory manager workarea list latch L 134transaction allocation L 1undo global data L 693active txn count during cleanout S 2buffer is not pinned count S 244bytes received via SQL*Net from client S 1,123bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 340calls to kcmgas S 542change write time S 65cleanout - number of ktugct calls S 150cluster key scan block gets S 4



cluster key scans S 2commit cleanouts S 452commit cleanouts successfully completed S 452commit txn count during cleanout S 150consistent changes S 2consistent gets - examination S 155CPU used by this session S 175CPU used when call started S 175CR blocks created S 2data blocks consistent reads - undo S 2records applieddb block changes S 177,204deferred (CURRENT) block cleanout S 2applicationsdirty buffers inspected S 2,309enqueue releases S 213enqueue requests S 215free buffer inspected S 2,819free buffer requested S 2,339hot buffers moved to head of LRU S 139immediate (CURRENT) block cleanout S 450applicationsindex fetch by key S 2index scans kdiixs1 S 11leaf node splits S 150messages sent S 63no work - consistent read gets S 231opened cursors cumulative S 18pinned buffers inspected S 60prefetched blocks S 176prefetched blocks aged out before use S 57recursive calls S 121redo buffer allocation retries S 2redo entries S 88,288redo log space requests S 2redo log space wait time S 41redo ordering marks S 132rollbacks only - consistent read gets S 2session pga memory S 16,336shared hash latch upgrades - no wait S 11SQL*Net roundtrips to/from client S 5switch current to new buffer S 150table scans (long tables) S 1user calls S 8write clones created in foreground S 107



buffer pool L 0cache buffers chains L 480,644cache buffers lru chain L 6,850enqueue hash chains L 444enqueues L 126library cache L 282library cache pin L 178redo allocation L 88,471redo copy L 88,333row cache enqueue latch L 204row cache objects L 219shared pool L 193execute count S 18parse count (hard) S 2parse count (total) S 18redo size S 22,887,828table fetch by rowid S 11table scan blocks gotten S 207table scan rows gotten S 100,000buffer is pinned count S 0consistent gets S 563db block gets S 96,896physical reads S 651physical writes S 0session logical reads S 97,459sorts (disk) S 0sorts (memory) S 0sorts (rows) S 0elapsed time (centiseconds) S 621

Actual Plan for Scenario UPDATE:PROBLEMSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=563 r=651 w=0 time=5998399 us)'STAT #1 id=2 cnt=80000 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=200 w=0 time=480438 us)'SQL>SQL>SQL>SQL> @hopttraceEnter the workspace name: updateEnter the scenario name: problem



Dump file e:\oracle\admin\hotsos\udump\hotsos_ora_1988.trcFri Mar 04 11:01:50 2005ORACLE V9.2.0.6.0 - Production vsnsta=0vsnsql=12 vsnxtr=3Windows 2000 Version 5.1 Service Pack 2, CPU type 586Oracle9i Enterprise Edition Release 9.2.0.6.0 - ProductionWith the Partitioning, OLAP and Oracle Data Mining optionsJServer Release 9.2.0.6.0 - ProductionWindows 2000 Version 5.1 Service Pack 2, CPU type 586Instance name: hotsosRedo thread mounted by this instance: 1Oracle process number: 13Windows thread id: 1988, image: ORACLE.EXE

*** SESSION ID:(7.214) 2005-03-04 11:01:50.148***************************************PARAMETERS USED BY THE OPTIMIZER********************************OPTIMIZER_FEATURES_ENABLE = 9.2.0OPTIMIZER_MODE/GOAL = Choose_OPTIMIZER_PERCENT_PARALLEL = 101HASH_AREA_SIZE = 4194304HASH_JOIN_ENABLED = TRUEHASH_MULTIBLOCK_IO_COUNT = 0SORT_AREA_SIZE = 2097152OPTIMIZER_SEARCH_LIMIT = 5PARTITION_VIEW_ENABLED = FALSE_ALWAYS_STAR_TRANSFORMATION = FALSE_B_TREE_BITMAP_PLANS = TRUESTAR_TRANSFORMATION_ENABLED = FALSE_COMPLEX_VIEW_MERGING = TRUE_PUSH_JOIN_PREDICATE = TRUEPARALLEL_BROADCAST_ENABLED = TRUEOPTIMIZER_MAX_PERMUTATIONS = 2000OPTIMIZER_INDEX_CACHING = 50_SYSTEM_INDEX_CACHING = 0OPTIMIZER_INDEX_COST_ADJ = 50OPTIMIZER_DYNAMIC_SAMPLING = 1_OPTIMIZER_DYN_SMP_BLKS = 32QUERY_REWRITE_ENABLED = TRUEQUERY_REWRITE_INTEGRITY = ENFORCED_INDEX_JOIN_ENABLED = TRUE_SORT_ELIMINATION_COST_RATIO = 0_OR_EXPAND_NVL_PREDICATE = TRUE



_NEW_INITIAL_JOIN_ORDERS = TRUEALWAYS_ANTI_JOIN = CHOOSEALWAYS_SEMI_JOIN = CHOOSE_OPTIMIZER_MODE_FORCE = TRUE_OPTIMIZER_UNDO_CHANGES = FALSE_UNNEST_SUBQUERY = TRUE_PUSH_JOIN_UNION_VIEW = TRUE_FAST_FULL_SCAN_ENABLED = TRUE_OPTIM_ENHANCE_NNULL_DETECTION = TRUE_ORDERED_NESTED_LOOP = TRUE_NESTED_LOOP_FUDGE = 100_NO_OR_EXPANSION = FALSE_QUERY_COST_REWRITE = TRUEQUERY_REWRITE_EXPRESSION = TRUE_IMPROVED_ROW_LENGTH_ENABLED = TRUE_USE_NOSEGMENT_INDEXES = FALSE_ENABLE_TYPE_DEP_SELECTIVITY = TRUE_IMPROVED_OUTERJOIN_CARD = TRUE_OPTIMIZER_ADJUST_FOR_NULLS = TRUE_OPTIMIZER_CHOOSE_PERMUTATION = 0_USE_COLUMN_STATS_FOR_FUNCTION = TRUE_SUBQUERY_PRUNING_ENABLED = TRUE_SUBQUERY_PRUNING_REDUCTION_FACTOR = 50_SUBQUERY_PRUNING_COST_FACTOR = 20_LIKE_WITH_BIND_AS_EQUALITY = FALSE_TABLE_SCAN_COST_PLUS_ONE = TRUE_SORTMERGE_INEQUALITY_JOIN_OFF = FALSE_DEFAULT_NON_EQUALITY_SEL_CHECK = TRUE_ONESIDE_COLSTAT_FOR_EQUIJOINS = TRUE_OPTIMIZER_COST_MODEL = CHOOSE_GSETS_ALWAYS_USE_TEMPTABLES = FALSEDB_FILE_MULTIBLOCK_READ_COUNT = 16_NEW_SORT_COST_ESTIMATE = TRUE_GS_ANTI_SEMI_JOIN_ALLOWED = TRUE_CPU_TO_IO = 0_PRED_MOVE_AROUND = TRUE***************************************BASE STATISTICAL INFORMATION***********************Table stats Table: T Alias: T

TOTAL :: CDN: 100000 NBLKS: 207 AVG_ROW_LEN: 13-- Index stats

INDEX NAME: SYS_C002345 COL#: 1TOTAL :: LVLS: 1 #LB: 187 #DK: 100000 LB/K: 1 DB/K: 1 CLUF: 204

INDEX NAME: T_N1 COL#: 2TOTAL :: LVLS: 1 #LB: 238 #DK: 3 LB/K: 79 DB/K: 68 CLUF: 204

INDEX NAME: T_N2 COL#: 3TOTAL :: LVLS: 1 #LB: 225 #DK: 2 LB/K: 112 DB/K: 204 CLUF: 408



INDEX NAME: T_N3 COL#: 2 3TOTAL :: LVLS: 1 #LB: 273 #DK: 6 LB/K: 45 DB/K: 68 CLUF: 410

_OPTIMIZER_PERCENT_PARALLEL = 0***************************************SINGLE TABLE ACCESS PATHColumn: STATUS Col#: 2 Table: T Alias: T

NDV: 3 NULLS: 0 DENS: 3.3333e-001 LO: 0 HI: 2NO HISTOGRAM: #BKT: 1 #VAL: 2

TABLE: T ORIG CDN: 100000 ROUNDED CDN: 33333 CMPTD CDN: 33333Access path: tsc Resc: 22 Resp: 22Access path: index (equal)

Index: T_N1TABLE: T

RSC_CPU: 0 RSC_IO: 148IX_SEL: 0.0000e+000 TB_SEL: 3.3333e-001Skip scan: ss-sel 0 andv 2ss cost 92index io scan cost 0

Access path: index (index-only)Index: T_N3

TABLE: TRSC_CPU: 0 RSC_IO: 92

IX_SEL: 3.3333e-001 TB_SEL: 3.3333e-001BEST_CST: 22.00 PATH: 2 Degree: 1

***************************************OPTIMIZER STATISTICS AND COMPUTATIONS***************************************GENERAL PLANS***********************Join order[1]: T[T]#0Best so far: TABLE#: 0 CST: 22 CDN: 33333 BYTES: 99999Final - All Rows Plan:

JOIN ORDER: 1CST: 22 CDN: 33333 RSC: 22 RSP: 22 BYTES: 99999IO-RSC: 22 IO-RSP: 22 CPU-RSC: 0 CPU-RSP: 0

QUERYexplain plan set statement_id='update:problem' forupdate t

set flag='B'where status=2

PLANCost of plan: 22Operation...........Object name.....Options.........Id...Pid..UPDATE STATEMENT 0UPDATE T 1TABLE ACCESS T FULL 2 1QUERYalter session set events '10053 trace name context off'



SQL>SQL>SQL>SQL>SQL>SQL> @horatraceEnter the workspace name: updateEnter the scenario name: problemReview tkprof output? (Y/N): YYour trace file (hotsos_ora_3364.trc) has been spooled to your default directory.Tkprof output will be displayed first (if requested).hotsos_ora_3364.trc will be displayed in your editor after any tkprof output.Press Enter to continue. . .TKPROF: Release 9.2.0.6.0 - Production on Fri Mar 4 11:29:18 2005Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.Trace file: hotsos_ora_3364.trcSort options: default. . .. . .update t


call count cpu elapsed disk query current rows------- ------ -------- ---------- ---------- ---------- ---------- ----------Parse 1 0.00 0.00 0 0 0 0Execute 1 1.73 6.00 651 563 96896 80000Fetch 0 0.00 0.00 0 0 0 0------- ------ -------- ---------- ---------- ---------- ---------- ----------total 2 1.73 6.00 651 563 96896 80000Misses in library cache during parse: 1Optimizer goal: CHOOSEParsing user id: 41Rows Row Source Operation------- ---------------------------------------------------

0 UPDATE (cr=563 r=651 w=0 time=5998399 us)80000 TABLE ACCESS FULL T (cr=211 r=200 w=0 time=480438 us)

. . .

. . .



Dump file e:\oracle\admin\hotsos\udump\hotsos_ora_3364.trc. . .. . .PARSING IN CURSOR #1 len=40 dep=0 uid=41 oct=6 lid=41 tim=90089340242 hv=1483413068 ad='2bf70aac'update t


END OF STMTPARSE #1:c=0,e=1509,p=0,cr=0,cu=0,mis=1,r=0,dep=0,og=4,tim=90089340234. . .. . .EXEC #1:c=1734375,e=6000464,p=651,cr=563,cu=96896,mis=0,r=80000,dep=0,og=4,tim=90095354755. . .. . .

SQL>SQL>SQL>SQL>SQL> get test_ans1

1 update t2 set flag='B'3 where status=24* and flag != 'B'

SQL>SQL>SQL> @dodmlEnter .sql file name (without extension): test_ans1Enter the workspace name: updateEnter the scenario name: answer1Display results of SQL (ON/OFF)?: offCapturing statistics information...=================================================================Name of 10046 trace file: hotsos_ora_1256.trc=================================================================Explain Plan for Scenario update:answer1

--------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |--------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 16667 | 50001 | 22 |



| 1 | UPDATE | T | | | ||* 2 | TABLE ACCESS FULL | T | 16667 | 50001 | 22 |--------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

2 - filter("T"."STATUS"=2 AND "T"."FLAG"'B')Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_1292.trc=================================================================

Actual Plan for Scenario update:answer1STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=215 r=717 w=0 time=2217354 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=205 w=0 time=277281 us)'SQL>SQL>SQL> @lsscstatList of values (Workspace)------------------------------------------------------------UPDATEWorkspace [UPDATE]:

List of values (Scenario)------------------------------------------------------------ANSWER1PROBLEMScenario [PROBLEM]: answer1

Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 4channel operations parent latch L 2checkpoint queue latch L 2,357child cursor hash table L 15Consistent RBA L 5dml lock allocation L 3hash table column usage latch L 6



lgwr LWN SCN L 5library cache pin allocation L 42list of block allocation L 6messages L 31mostly latch-free SCN L 5multiblock read objects L 48post/wait queue L 4redo writing L 21session allocation L 2session idle bit L 17sim partition latch L 2simulator hash latch L 464simulator lru latch L 91SQL memory manager latch L 1SQL memory manager workarea list latch L 67undo global data L 10buffer is not pinned count S 210bytes received via SQL*Net from client S 1,142bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 9calls to kcmgas S 178CPU used by this session S 33CPU used when call started S 33db block changes S 16,111dirty buffers inspected S 835enqueue releases S 4enqueue requests S 6free buffer inspected S 898free buffer requested S 981hot buffers moved to head of LRU S 365index scans kdiixs1 S 1messages sent S 6no work - consistent read gets S 209opened cursors cumulative S 6pinned buffers inspected S 36prefetched blocks S 181prefetched blocks aged out before use S 25recursive calls S 8redo entries S 8,011session pga memory S 189,544shared hash latch upgrades - no wait S 1SQL*Net roundtrips to/from client S 5switch current to new buffer S 166table scans (long tables) S 1user calls S 8write clones created in foreground S 12buffer pool L 0



cache buffers chains L 65,004cache buffers lru chain L 2,507enqueue hash chains L 16enqueues L 11library cache L 150library cache pin L 82redo allocation L 8,038redo copy L 8,028row cache enqueue latch L 58row cache objects L 61shared pool L 136execute count S 6parse count (hard) S 2parse count (total) S 6redo size S 1,633,416table fetch by rowid S 1table scan blocks gotten S 207table scan rows gotten S 100,000buffer is pinned count S 0consistent gets S 215db block gets S 14,585physical reads S 717physical writes S 0session logical reads S 14,800sorts (disk) S 0sorts (memory) S 0sorts (rows) S 0elapsed time (centiseconds) S 234

Actual Plan for Scenario UPDATE:ANSWER1STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=215 r=717 w=0 time=2217354 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=205 w=0 time=277281 us)'SQL>SQL>SQL>SQL> @diffList of values (First workspace)------------------------------------------------------------UPDATE



First workspace []: update

List of values (First scenario)------------------------------------------------------------ANSWER1PROBLEMFirst scenario []: problem

List of values (Second workspace)------------------------------------------------------------UPDATESecond workspace []: update

List of values (Second scenario)------------------------------------------------------------ANSWER1PROBLEMSecond scenario []: answer1

Statistic Name UPDATE UPDATEStatistic Type (S=stat, L=Latch) PROBLEM ANSWER1 Difference---------------------------------------- - -------------- -------------- --------------active checkpoint queue latch L 10 4 -6cache buffer handles L 54 0 -54channel operations parent latch L 4 2 -2checkpoint queue latch L 6,935 2,357 -4,578Consistent RBA L 66 5 -61dml lock allocation L 7 3 -4FIB s.o chain latch L 4 0 -4FOB s.o list latch L 4 0 -4hash table column usage latch L 4 6 2lgwr LWN SCN L 66 5 -61library cache pin allocation L 90 42 -48list of block allocation L 7 6 -1messages L 258 31 -227mostly latch-free SCN L 66 5 -61post/wait queue L 38 4 -34redo writing L 216 21 -195session timer L 2 0 -2sim partition latch L 20 2 -18simulator hash latch L 5,867 464 -5,403



simulator lru latch L 206 91 -115SQL memory manager latch L 2 1 -1SQL memory manager workarea list latch L 134 67 -67transaction allocation L 1 0 -1undo global data L 693 10 -683active txn count during cleanout S 2 0 -2buffer is not pinned count S 244 210 -34bytes received via SQL*Net from client S 1,123 1,142 19calls to get snapshot scn: kcmgss S 340 9 -331calls to kcmgas S 542 178 -364change write time S 65 0 -65cleanout - number of ktugct calls S 150 0 -150cluster key scan block gets S 4 0 -4cluster key scans S 2 0 -2commit cleanouts S 452 0 -452commit cleanouts successfully completed S 452 0 -452commit txn count during cleanout S 150 0 -150consistent changes S 2 0 -2consistent gets - examination S 155 0 -155CPU used by this session S 175 33 -142CPU used when call started S 175 33 -142CR blocks created S 2 0 -2data blocks consistent reads - undo S 2 0 -2records applieddb block changes S 177,204 16,111 -161,093deferred (CURRENT) block cleanout S 2 0 -2applicationsdirty buffers inspected S 2,309 835 -1,474enqueue releases S 213 4 -209enqueue requests S 215 6 -209free buffer inspected S 2,819 898 -1,921free buffer requested S 2,339 981 -1,358hot buffers moved to head of LRU S 139 365 226immediate (CURRENT) block cleanout S 450 0 -450applicationsindex fetch by key S 2 0 -2index scans kdiixs1 S 11 1 -10leaf node splits S 150 0 -150messages sent S 63 6 -57no work - consistent read gets S 231 209 -22opened cursors cumulative S 18 6 -12pinned buffers inspected S 60 36 -24prefetched blocks S 176 181 5prefetched blocks aged out before use S 57 25 -32recursive calls S 121 8 -113



redo buffer allocation retries S 2 0 -2redo entries S 88,288 8,011 -80,277redo log space requests S 2 0 -2redo log space wait time S 41 0 -41redo ordering marks S 132 0 -132rollbacks only - consistent read gets S 2 0 -2session pga memory S 16,336 189,544 173,208shared hash latch upgrades - no wait S 11 1 -10switch current to new buffer S 150 166 16write clones created in foreground S 107 12 -95

buffer pool L 0 0 0cache buffers chains L 480,644 65,004 -415,640cache buffers lru chain L 6,850 2,507 -4,343enqueue hash chains L 444 16 -428enqueues L 126 11 -115library cache L 282 150 -132library cache pin L 178 82 -96redo allocation L 88,471 8,038 -80,433redo copy L 88,333 8,028 -80,305row cache enqueue latch L 204 58 -146row cache objects L 219 61 -158shared pool L 193 136 -57

execute count S 18 6 -12parse count (hard) S 2 2 0parse count (total) S 18 6 -12redo size S 22,887,828 1,633,416 -21,254,412table fetch by rowid S 11 1 -10table scan blocks gotten S 207 207 0table scan rows gotten S 100,000 100,000 0

buffer is pinned count S 0 0 0consistent gets S 563 215 -348db block gets S 96,896 14,585 -82,311physical reads S 651 717 66physical writes S 0 0 0session logical reads S 97,459 14,800 -82,659sorts (disk) S 0 0 0sorts (memory) S 0 0 0sorts (rows) S 0 0 0

elapsed time S 621 234 -387



elapsed time (in seconds) S 6.21 2.34 -3.87List of values (Show actual 10046 STAT lines)------------------------------------------------------------YESNOShow actual 10046 STAT lines [YES]:Actual Plan for Scenario UPDATE:PROBLEMSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=563 r=651 w=0 time=5998399 us)'STAT #1 id=2 cnt=80000 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=200 w=0 time=480438 us)'Actual Plan for Scenario UPDATE:ANSWER1STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=215 r=717 w=0 time=2217354 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=205 w=0 time=277281 us)'

List of values (Show EXPLAIN PLAN output)------------------------------------------------------------YESNOShow EXPLAIN PLAN output [YES]:

==========================================================================UPDATE:PROBLEM--------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |--------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 33333 | 99999 | 22 || 1 | UPDATE | T | | | ||* 2 | TABLE ACCESS FULL | T | 33333 | 99999 | 22 |--------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

2 - filter("T"."STATUS"=2)Note: cpu costing is off



==========================================================================UPDATE:ANSWER1--------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |--------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 16667 | 50001 | 22 || 1 | UPDATE | T | | | ||* 2 | TABLE ACCESS FULL | T | 16667 | 50001 | 22 |--------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

2 - filter("T"."STATUS"=2 AND "T"."FLAG"'B')Note: cpu costing is off==========================================================================SQL>SQL> get test_ans2

1 update t2 set flag='B'3 where status=24* and flag in (select flag from flags minus select 'B' from dual )


----------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |----------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 83333 | 488K| 26 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 83333 | 488K| 26 || 3 | VIEW | VW_NSO_1 | 5 | 15 | 25 |



| 4 | MINUS | | | | || 5 | SORT UNIQUE | | 5 | 5 | || 6 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 5 | 5 | 1 || 7 | TABLE ACCESS FULL| DUAL | 8168 | | 11 ||* 8 | INDEX RANGE SCAN | T_N3 | 16667 | 50001 | |----------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

8 - access("T"."STATUS"=2 AND "T"."FLAG"="VW_NSO_1"."$nso_col_1")Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_2552.trc=================================================================

Actual Plan for Scenario update:answer2STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=494 w=0 time=1203620 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=3 w=0 time=40684 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=15222 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=15205 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=15077 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=14973 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=84 us)'STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=2 w=0 time=18340 us)'SQL>SQL>SQL> @lsscstatList of values (Workspace)------------------------------------------------------------UPDATEWorkspace [UPDATE]:

List of values (Scenario)------------------------------------------------------------ANSWER1ANSWER2PROBLEMScenario [ANSWER1]: answer2



Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 4channel operations parent latch L 2checkpoint queue latch L 1,641child cursor hash table L 15Consistent RBA L 4dml lock allocation L 3hash table column usage latch L 10lgwr LWN SCN L 4library cache load lock L 2library cache pin allocation L 58list of block allocation L 6messages L 25mostly latch-free SCN L 4post/wait queue L 2redo writing L 18session allocation L 2session idle bit L 17session timer L 1sim partition latch L 1simulator hash latch L 258simulator lru latch L 62SQL memory manager latch L 1SQL memory manager workarea list latch L 71undo global data L 6buffer is not pinned count S 2bytes received via SQL*Net from client S 1,191bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 8calls to kcmgas S 4consistent gets - examination S 1CPU used by this session S 11CPU used when call started S 11cursor authentications S 1db block changes S 4,421dirty buffers inspected S 538enqueue releases S 2enqueue requests S 4free buffer inspected S 541free buffer requested S 537hot buffers moved to head of LRU S 222index scans kdiixs1 S 9messages sent S 4no work - consistent read gets S 7opened cursors cumulative S 7parse time cpu S 2



parse time elapsed S 13pinned buffers inspected S 3recursive calls S 5recursive cpu usage S 2redo entries S 2,189shared hash latch upgrades - no wait S 10SQL*Net roundtrips to/from client S 5table scans (short tables) S 1user calls S 8workarea executions - optimal S 5write clones created in foreground S 4buffer pool L 0cache buffers chains L 16,101cache buffers lru chain L 1,434enqueue hash chains L 12enqueues L 7library cache L 208library cache pin L 100redo allocation L 2,217redo copy L 2,209row cache enqueue latch L 120row cache objects L 123shared pool L 180execute count S 7parse count (hard) S 2parse count (total) S 7redo size S 638,912table fetch by rowid S 0table scan blocks gotten S 1table scan rows gotten S 1buffer is pinned count S 2consistent gets S 20db block gets S 2,840physical reads S 498physical writes S 0session logical reads S 2,860sorts (disk) S 0sorts (memory) S 5sorts (rows) S 6,405elapsed time (centiseconds) S 151

Actual Plan for Scenario UPDATE:ANSWER2



STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=494 w=0 time=1203620 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=3 w=0 time=40684 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=15222 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=15205 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=15077 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=14973 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=84 us)'STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=2 w=0 time=18340 us)'SQL>SQL>SQL>SQL> @hrank updateScenario ranking for workspace update by elapsed time

Elapsed Time (secs) Scenario Name--------------------- --------------------------------------------------------------------------------

1.510000 ANSWER22.340000 ANSWER16.210000 PROBLEM

SQL>SQL> @diffList of values (First workspace)------------------------------------------------------------UPDATEFirst workspace [UPDATE]:

List of values (First scenario)------------------------------------------------------------ANSWER1ANSWER2PROBLEMFirst scenario [PROBLEM]:

List of values (Second workspace)------------------------------------------------------------UPDATESecond workspace [UPDATE]:



List of values (Second scenario)------------------------------------------------------------ANSWER1ANSWER2PROBLEMSecond scenario [ANSWER1]: answer2

Statistic Name UPDATE UPDATEStatistic Type (S=stat, L=Latch) PROBLEM ANSWER2 Difference---------------------------------------- - -------------- -------------- --------------active checkpoint queue latch L 10 4 -6cache buffer handles L 54 0 -54channel operations parent latch L 4 2 -2checkpoint queue latch L 6,935 1,641 -5,294Consistent RBA L 66 4 -62dml lock allocation L 7 3 -4FIB s.o chain latch L 4 0 -4FOB s.o list latch L 4 0 -4hash table column usage latch L 4 10 6lgwr LWN SCN L 66 4 -62library cache load lock L 0 2 2library cache pin allocation L 90 58 -32list of block allocation L 7 6 -1messages L 258 25 -233mostly latch-free SCN L 66 4 -62multiblock read objects L 48 0 -48post/wait queue L 38 2 -36redo writing L 216 18 -198session timer L 2 1 -1sim partition latch L 20 1 -19simulator hash latch L 5,867 258 -5,609simulator lru latch L 206 62 -144SQL memory manager latch L 2 1 -1SQL memory manager workarea list latch L 134 71 -63transaction allocation L 1 0 -1undo global data L 693 6 -687active txn count during cleanout S 2 0 -2buffer is not pinned count S 244 2 -242bytes received via SQL*Net from client S 1,123 1,191 68calls to get snapshot scn: kcmgss S 340 8 -332calls to kcmgas S 542 4 -538change write time S 65 0 -65cleanout - number of ktugct calls S 150 0 -150cluster key scan block gets S 4 0 -4cluster key scans S 2 0 -2commit cleanouts S 452 0 -452



commit cleanouts successfully completed S 452 0 -452commit txn count during cleanout S 150 0 -150consistent changes S 2 0 -2consistent gets - examination S 155 1 -154CPU used by this session S 175 11 -164CPU used when call started S 175 11 -164CR blocks created S 2 0 -2cursor authentications S 0 1 1data blocks consistent reads - undo S 2 0 -2records applieddb block changes S 177,204 4,421 -172,783deferred (CURRENT) block cleanout S 2 0 -2applicationsdirty buffers inspected S 2,309 538 -1,771enqueue releases S 213 2 -211enqueue requests S 215 4 -211free buffer inspected S 2,819 541 -2,278free buffer requested S 2,339 537 -1,802hot buffers moved to head of LRU S 139 222 83immediate (CURRENT) block cleanout S 450 0 -450applicationsindex fetch by key S 2 0 -2index scans kdiixs1 S 11 9 -2leaf node splits S 150 0 -150messages sent S 63 4 -59no work - consistent read gets S 231 7 -224opened cursors cumulative S 18 7 -11parse time cpu S 0 2 2parse time elapsed S 0 13 13pinned buffers inspected S 60 3 -57prefetched blocks S 176 0 -176prefetched blocks aged out before use S 57 0 -57recursive calls S 121 5 -116recursive cpu usage S 0 2 2redo buffer allocation retries S 2 0 -2redo entries S 88,288 2,189 -86,099redo log space requests S 2 0 -2redo log space wait time S 41 0 -41redo ordering marks S 132 0 -132rollbacks only - consistent read gets S 2 0 -2session pga memory S 16,336 0 -16,336shared hash latch upgrades - no wait S 11 10 -1switch current to new buffer S 150 0 -150table scans (long tables) S 1 0 -1table scans (short tables) S 0 1 1



workarea executions - optimal S 0 5 5write clones created in foreground S 107 4 -103

buffer pool L 0 0 0cache buffers chains L 480,644 16,101 -464,543cache buffers lru chain L 6,850 1,434 -5,416enqueue hash chains L 444 12 -432enqueues L 126 7 -119library cache L 282 208 -74library cache pin L 178 100 -78redo allocation L 88,471 2,217 -86,254redo copy L 88,333 2,209 -86,124row cache enqueue latch L 204 120 -84row cache objects L 219 123 -96shared pool L 193 180 -13

execute count S 18 7 -11parse count (hard) S 2 2 0parse count (total) S 18 7 -11redo size S 22,887,828 638,912 -22,248,916table fetch by rowid S 11 0 -11table scan blocks gotten S 207 1 -206table scan rows gotten S 100,000 1 -99,999

buffer is pinned count S 0 2 2consistent gets S 563 20 -543db block gets S 96,896 2,840 -94,056physical reads S 651 498 -153physical writes S 0 0 0session logical reads S 97,459 2,860 -94,599sorts (disk) S 0 0 0sorts (memory) S 0 5 5sorts (rows) S 0 6,405 6,405


elapsed time (in seconds) S 6.21 1.51 -4.70List of values (Show actual 10046 STAT lines)------------------------------------------------------------YESNO



Show actual 10046 STAT lines [YES]:

Actual Plan for Scenario UPDATE:PROBLEMSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=563 r=651 w=0 time=5998399 us)'STAT #1 id=2 cnt=80000 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=200 w=0 time=480438 us)'Actual Plan for Scenario UPDATE:ANSWER2STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=494 w=0 time=1203620 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=3 w=0 time=40684 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=15222 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=15205 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=15077 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=14973 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=84 us)'STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=2 w=0 time=18340 us)'



2 - filter("T"."STATUS"=2)Note: cpu costing is off



==========================================================================UPDATE:ANSWER2----------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |----------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 83333 | 488K| 26 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 83333 | 488K| 26 || 3 | VIEW | VW_NSO_1 | 5 | 15 | 25 || 4 | MINUS | | | | || 5 | SORT UNIQUE | | 5 | 5 | || 6 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 5 | 5 | 1 || 7 | TABLE ACCESS FULL| DUAL | 8168 | | 11 ||* 8 | INDEX RANGE SCAN | T_N3 | 16667 | 50001 | |----------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

8 - access("T"."STATUS"=2 AND "T"."FLAG"="VW_NSO_1"."$nso_col_1")Note: cpu costing is off==========================================================================SQL>SQL> @diffList of values (First workspace)------------------------------------------------------------UPDATEFirst workspace [UPDATE]:

List of values (First scenario)------------------------------------------------------------ANSWER1ANSWER2PROBLEMFirst scenario [PROBLEM]: answer1

List of values (Second workspace)------------------------------------------------------------UPDATE



Second workspace [UPDATE]:

List of values (Second scenario)------------------------------------------------------------ANSWER1ANSWER2PROBLEMSecond scenario [ANSWER2]:

Statistic Name UPDATE UPDATEStatistic Type (S=stat, L=Latch) ANSWER1 ANSWER2 Difference---------------------------------------- - -------------- -------------- --------------checkpoint queue latch L 2,357 1,641 -716Consistent RBA L 5 4 -1hash table column usage latch L 6 10 4lgwr LWN SCN L 5 4 -1library cache load lock L 0 2 2library cache pin allocation L 42 58 16messages L 31 25 -6mostly latch-free SCN L 5 4 -1multiblock read objects L 48 0 -48post/wait queue L 4 2 -2redo writing L 21 18 -3session timer L 0 1 1sim partition latch L 2 1 -1simulator hash latch L 464 258 -206simulator lru latch L 91 62 -29SQL memory manager workarea list latch L 67 71 4undo global data L 10 6 -4buffer is not pinned count S 210 2 -208bytes received via SQL*Net from client S 1,142 1,191 49calls to get snapshot scn: kcmgss S 9 8 -1calls to kcmgas S 178 4 -174consistent gets - examination S 0 1 1CPU used by this session S 33 11 -22CPU used when call started S 33 11 -22cursor authentications S 0 1 1db block changes S 16,111 4,421 -11,690dirty buffers inspected S 835 538 -297enqueue releases S 4 2 -2enqueue requests S 6 4 -2free buffer inspected S 898 541 -357free buffer requested S 981 537 -444hot buffers moved to head of LRU S 365 222 -143index scans kdiixs1 S 1 9 8



messages sent S 6 4 -2no work - consistent read gets S 209 7 -202opened cursors cumulative S 6 7 1parse time cpu S 0 2 2parse time elapsed S 0 13 13pinned buffers inspected S 36 3 -33prefetched blocks S 181 0 -181prefetched blocks aged out before use S 25 0 -25recursive calls S 8 5 -3recursive cpu usage S 0 2 2redo entries S 8,011 2,189 -5,822session pga memory S 189,544 0 -189,544shared hash latch upgrades - no wait S 1 10 9switch current to new buffer S 166 0 -166table scans (long tables) S 1 0 -1table scans (short tables) S 0 1 1workarea executions - optimal S 0 5 5write clones created in foreground S 12 4 -8

buffer pool L 0 0 0cache buffers chains L 65,004 16,101 -48,903cache buffers lru chain L 2,507 1,434 -1,073enqueue hash chains L 16 12 -4enqueues L 11 7 -4library cache L 150 208 58library cache pin L 82 100 18redo allocation L 8,038 2,217 -5,821redo copy L 8,028 2,209 -5,819row cache enqueue latch L 58 120 62row cache objects L 61 123 62shared pool L 136 180 44

execute count S 6 7 1parse count (hard) S 2 2 0parse count (total) S 6 7 1redo size S 1,633,416 638,912 -994,504table fetch by rowid S 1 0 -1table scan blocks gotten S 207 1 -206table scan rows gotten S 100,000 1 -99,999

buffer is pinned count S 0 2 2consistent gets S 215 20 -195db block gets S 14,585 2,840 -11,745physical reads S 717 498 -219physical writes S 0 0 0



session logical reads S 14,800 2,860 -11,940sorts (disk) S 0 0 0sorts (memory) S 0 5 5sorts (rows) S 0 6,405 6,405


elapsed time (in seconds) S 2.34 1.51 -0.83List of values (Show actual 10046 STAT lines)------------------------------------------------------------YESNOShow actual 10046 STAT lines [YES]:

Actual Plan for Scenario UPDATE:ANSWER1STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=215 r=717 w=0 time=2217354 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=205 w=0 time=277281 us)'Actual Plan for Scenario UPDATE:ANSWER2STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=494 w=0 time=1203620 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=3 w=0 time=40684 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=15222 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=15205 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=15077 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=14973 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=84 us)'STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=2 w=0 time=18340 us)'


==========================================================================UPDATE:ANSWER1



--------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |--------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 16667 | 50001 | 22 || 1 | UPDATE | T | | | ||* 2 | TABLE ACCESS FULL | T | 16667 | 50001 | 22 |--------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

2 - filter("T"."STATUS"=2 AND "T"."FLAG"'B')Note: cpu costing is off==========================================================================UPDATE:ANSWER2----------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |----------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 83333 | 488K| 26 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 83333 | 488K| 26 || 3 | VIEW | VW_NSO_1 | 5 | 15 | 25 || 4 | MINUS | | | | || 5 | SORT UNIQUE | | 5 | 5 | || 6 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 5 | 5 | 1 || 7 | TABLE ACCESS FULL| DUAL | 8168 | | 11 ||* 8 | INDEX RANGE SCAN | T_N3 | 16667 | 50001 | |----------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

8 - access("T"."STATUS"=2 AND "T"."FLAG"="VW_NSO_1"."$nso_col_1")Note: cpu costing is off==========================================================================SQL>SQL>SQL> get test_ans3

1 update t2 set flag='B'3 where status=24* and flag in (select flag from flags where flag != 'B')




---------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |---------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 33333 | 130K| 2 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 33333 | 130K| 2 ||* 3 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 4 | 4 | 1 ||* 4 | INDEX RANGE SCAN | T_N3 | 8333 | 24999 | |---------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

3 - filter("FLAGS"."FLAG"'B')4 - access("T"."STATUS"=2 AND "T"."FLAG"="FLAGS"."FLAG")

Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_1200.trc=================================================================

Actual Plan for Scenario update:answer3STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=12 r=212 w=0 time=666891 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=12 r=2 w=0 time=29875 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=13743 us)'STAT #1 id=4 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11135 us)'SQL>SQL>SQL> @lsscstat



List of values (Workspace)------------------------------------------------------------UPDATEWorkspace [UPDATE]:

List of values (Scenario)------------------------------------------------------------ANSWER1ANSWER2ANSWER3PROBLEMScenario [ANSWER2]: answer3

Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 4checkpoint queue latch L 910child cursor hash table L 14Consistent RBA L 3dml lock allocation L 3hash table column usage latch L 15lgwr LWN SCN L 3library cache pin allocation L 42list of block allocation L 6messages L 22mostly latch-free SCN L 3redo writing L 13session idle bit L 16simulator hash latch L 203simulator lru latch L 29SQL memory manager workarea list latch L 4undo global data L 6buffer is not pinned count S 1bytes received via SQL*Net from client S 1,181bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 3calls to kcmgas S 1consistent gets - examination S 1CPU used by this session S 12CPU used when call started S 12db block changes S 4,421dirty buffers inspected S 2enqueue releases S 2



enqueue requests S 4free buffer inspected S 2free buffer requested S 247hot buffers moved to head of LRU S 303index scans kdiixs1 S 5messages sent S 3no work - consistent read gets S 6opened cursors cumulative S 5redo entries S 2,189shared hash latch upgrades - no wait S 6SQL*Net roundtrips to/from client S 5user calls S 8workarea executions - optimal S 4write clones created in foreground S 1buffer pool L 0cache buffers chains L 13,914cache buffers lru chain L 504enqueue hash chains L 10enqueues L 4library cache L 156library cache pin L 78redo allocation L 2,212redo copy L 2,206row cache enqueue latch L 74row cache objects L 77shared pool L 152execute count S 5parse count (hard) S 2parse count (total) S 5redo size S 638,912table fetch by rowid S 0table scan blocks gotten S 0table scan rows gotten S 0buffer is pinned count S 2consistent gets S 12db block gets S 2,840physical reads S 212physical writes S 0session logical reads S 2,852sorts (disk) S 0sorts (memory) S 2sorts (rows) S 6,400elapsed time (centiseconds) S 102



Actual Plan for Scenario UPDATE:ANSWER3STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=12 r=212 w=0 time=666891 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=12 r=2 w=0 time=29875 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=13743 us)'STAT #1 id=4 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11135 us)'SQL>SQL>SQL>SQL> @hrank updateScenario ranking for workspace update by elapsed time


1.020000 ANSWER31.510000 ANSWER22.340000 ANSWER16.210000 PROBLEM

SQL> @diffList of values (First workspace)------------------------------------------------------------UPDATEFirst workspace [UPDATE]:

List of values (First scenario)------------------------------------------------------------ANSWER1ANSWER2ANSWER3PROBLEMFirst scenario [ANSWER1]: problem




List of values (Second scenario)------------------------------------------------------------ANSWER1ANSWER2ANSWER3PROBLEMSecond scenario [ANSWER2]: answer3

Statistic Name UPDATE UPDATEStatistic Type (S=stat, L=Latch) PROBLEM ANSWER3 Difference---------------------------------------- - -------------- -------------- --------------active checkpoint queue latch L 10 4 -6cache buffer handles L 54 0 -54channel operations parent latch L 4 0 -4checkpoint queue latch L 6,935 910 -6,025child cursor hash table L 15 14 -1Consistent RBA L 66 3 -63dml lock allocation L 7 3 -4FIB s.o chain latch L 4 0 -4FOB s.o list latch L 4 0 -4hash table column usage latch L 4 15 11lgwr LWN SCN L 66 3 -63library cache pin allocation L 90 42 -48list of block allocation L 7 6 -1messages L 258 22 -236mostly latch-free SCN L 66 3 -63multiblock read objects L 48 0 -48post/wait queue L 38 0 -38redo writing L 216 13 -203session allocation L 2 0 -2session idle bit L 17 16 -1session timer L 2 0 -2sim partition latch L 20 0 -20simulator hash latch L 5,867 203 -5,664simulator lru latch L 206 29 -177SQL memory manager latch L 2 0 -2SQL memory manager workarea list latch L 134 4 -130transaction allocation L 1 0 -1undo global data L 693 6 -687active txn count during cleanout S 2 0 -2buffer is not pinned count S 244 1 -243bytes received via SQL*Net from client S 1,123 1,181 58calls to get snapshot scn: kcmgss S 340 3 -337calls to kcmgas S 542 1 -541change write time S 65 0 -65



cleanout - number of ktugct calls S 150 0 -150cluster key scan block gets S 4 0 -4cluster key scans S 2 0 -2commit cleanouts S 452 0 -452commit cleanouts successfully completed S 452 0 -452commit txn count during cleanout S 150 0 -150consistent changes S 2 0 -2consistent gets - examination S 155 1 -154CPU used by this session S 175 12 -163CPU used when call started S 175 12 -163CR blocks created S 2 0 -2data blocks consistent reads - undo S 2 0 -2records applieddb block changes S 177,204 4,421 -172,783deferred (CURRENT) block cleanout S 2 0 -2applicationsdirty buffers inspected S 2,309 2 -2,307enqueue releases S 213 2 -211enqueue requests S 215 4 -211free buffer inspected S 2,819 2 -2,817free buffer requested S 2,339 247 -2,092hot buffers moved to head of LRU S 139 303 164immediate (CURRENT) block cleanout S 450 0 -450applicationsindex fetch by key S 2 0 -2index scans kdiixs1 S 11 5 -6leaf node splits S 150 0 -150messages sent S 63 3 -60no work - consistent read gets S 231 6 -225opened cursors cumulative S 18 5 -13pinned buffers inspected S 60 0 -60prefetched blocks S 176 0 -176prefetched blocks aged out before use S 57 0 -57recursive calls S 121 0 -121redo buffer allocation retries S 2 0 -2redo entries S 88,288 2,189 -86,099redo log space requests S 2 0 -2redo log space wait time S 41 0 -41redo ordering marks S 132 0 -132rollbacks only - consistent read gets S 2 0 -2session pga memory S 16,336 0 -16,336shared hash latch upgrades - no wait S 11 6 -5switch current to new buffer S 150 0 -150table scans (long tables) S 1 0 -1workarea executions - optimal S 0 4 4



write clones created in foreground S 107 1 -106

buffer pool L 0 0 0cache buffers chains L 480,644 13,914 -466,730cache buffers lru chain L 6,850 504 -6,346enqueue hash chains L 444 10 -434enqueues L 126 4 -122library cache L 282 156 -126library cache pin L 178 78 -100redo allocation L 88,471 2,212 -86,259redo copy L 88,333 2,206 -86,127row cache enqueue latch L 204 74 -130row cache objects L 219 77 -142shared pool L 193 152 -41

execute count S 18 5 -13parse count (hard) S 2 2 0parse count (total) S 18 5 -13redo size S 22,887,828 638,912 -22,248,916table fetch by rowid S 11 0 -11table scan blocks gotten S 207 0 -207table scan rows gotten S 100,000 0 -100,000

buffer is pinned count S 0 2 2consistent gets S 563 12 -551db block gets S 96,896 2,840 -94,056physical reads S 651 212 -439physical writes S 0 0 0session logical reads S 97,459 2,852 -94,607sorts (disk) S 0 0 0sorts (memory) S 0 2 2sorts (rows) S 0 6,400 6,400


elapsed time (in seconds) S 6.21 1.02 -5.19List of values (Show actual 10046 STAT lines)------------------------------------------------------------YESNO



Show actual 10046 STAT lines [YES]:

Actual Plan for Scenario UPDATE:PROBLEMSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=563 r=651 w=0 time=5998399 us)'STAT #1 id=2 cnt=80000 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=200 w=0 time=480438 us)'Actual Plan for Scenario UPDATE:ANSWER3STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=12 r=212 w=0 time=666891 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=12 r=2 w=0 time=29875 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=13743 us)'STAT #1 id=4 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11135 us)'



2 - filter("T"."STATUS"=2)Note: cpu costing is off==========================================================================UPDATE:ANSWER3---------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |



---------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 33333 | 130K| 2 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 33333 | 130K| 2 ||* 3 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 4 | 4 | 1 ||* 4 | INDEX RANGE SCAN | T_N3 | 8333 | 24999 | |---------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------


Note: cpu costing is off==========================================================================SQL>SQL>SQL> @diffList of values (First workspace)------------------------------------------------------------UPDATEFirst workspace [UPDATE]:

List of values (First scenario)------------------------------------------------------------ANSWER1ANSWER2ANSWER3PROBLEMFirst scenario [PROBLEM]: answer2


List of values (Second scenario)------------------------------------------------------------ANSWER1



ANSWER2ANSWER3PROBLEMSecond scenario [ANSWER3]:

Statistic Name UPDATE UPDATEStatistic Type (S=stat, L=Latch) ANSWER2 ANSWER3 Difference---------------------------------------- - -------------- -------------- --------------channel operations parent latch L 2 0 -2checkpoint queue latch L 1,641 910 -731child cursor hash table L 15 14 -1Consistent RBA L 4 3 -1hash table column usage latch L 10 15 5lgwr LWN SCN L 4 3 -1library cache load lock L 2 0 -2library cache pin allocation L 58 42 -16messages L 25 22 -3mostly latch-free SCN L 4 3 -1post/wait queue L 2 0 -2redo writing L 18 13 -5session allocation L 2 0 -2session idle bit L 17 16 -1session timer L 1 0 -1sim partition latch L 1 0 -1simulator hash latch L 258 203 -55simulator lru latch L 62 29 -33SQL memory manager latch L 1 0 -1SQL memory manager workarea list latch L 71 4 -67buffer is not pinned count S 2 1 -1bytes received via SQL*Net from client S 1,191 1,181 -10calls to get snapshot scn: kcmgss S 8 3 -5calls to kcmgas S 4 1 -3CPU used by this session S 11 12 1CPU used when call started S 11 12 1cursor authentications S 1 0 -1dirty buffers inspected S 538 2 -536free buffer inspected S 541 2 -539free buffer requested S 537 247 -290hot buffers moved to head of LRU S 222 303 81index scans kdiixs1 S 9 5 -4messages sent S 4 3 -1no work - consistent read gets S 7 6 -1opened cursors cumulative S 7 5 -2parse time cpu S 2 0 -2parse time elapsed S 13 0 -13pinned buffers inspected S 3 0 -3



recursive calls S 5 0 -5recursive cpu usage S 2 0 -2shared hash latch upgrades - no wait S 10 6 -4table scans (short tables) S 1 0 -1workarea executions - optimal S 5 4 -1write clones created in foreground S 4 1 -3

buffer pool L 0 0 0cache buffers chains L 16,101 13,914 -2,187cache buffers lru chain L 1,434 504 -930enqueue hash chains L 12 10 -2enqueues L 7 4 -3library cache L 208 156 -52library cache pin L 100 78 -22redo allocation L 2,217 2,212 -5redo copy L 2,209 2,206 -3row cache enqueue latch L 120 74 -46row cache objects L 123 77 -46shared pool L 180 152 -28

execute count S 7 5 -2parse count (hard) S 2 2 0parse count (total) S 7 5 -2redo size S 638,912 638,912 0table fetch by rowid S 0 0 0table scan blocks gotten S 1 0 -1table scan rows gotten S 1 0 -1

buffer is pinned count S 2 2 0consistent gets S 20 12 -8db block gets S 2,840 2,840 0physical reads S 498 212 -286physical writes S 0 0 0session logical reads S 2,860 2,852 -8sorts (disk) S 0 0 0sorts (memory) S 5 2 -3sorts (rows) S 6,405 6,400 -5


elapsed time (in seconds) S 1.51 1.02 -0.49



List of values (Show actual 10046 STAT lines)------------------------------------------------------------YESNOShow actual 10046 STAT lines [YES]:

Actual Plan for Scenario UPDATE:ANSWER2STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=494 w=0 time=1203620 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=3 w=0 time=40684 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=15222 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=15205 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=15077 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=14973 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=84 us)'STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=2 w=0 time=18340 us)'Actual Plan for Scenario UPDATE:ANSWER3STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=12 r=212 w=0 time=666891 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=12 r=2 w=0 time=29875 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=13743 us)'STAT #1 id=4 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11135 us)'


==========================================================================UPDATE:ANSWER2----------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |----------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 83333 | 488K| 26 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 83333 | 488K| 26 || 3 | VIEW | VW_NSO_1 | 5 | 15 | 25 || 4 | MINUS | | | | || 5 | SORT UNIQUE | | 5 | 5 | |



| 6 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 5 | 5 | 1 || 7 | TABLE ACCESS FULL| DUAL | 8168 | | 11 ||* 8 | INDEX RANGE SCAN | T_N3 | 16667 | 50001 | |----------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

8 - access("T"."STATUS"=2 AND "T"."FLAG"="VW_NSO_1"."$nso_col_1")Note: cpu costing is off==========================================================================UPDATE:ANSWER3---------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |---------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 33333 | 130K| 2 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 33333 | 130K| 2 ||* 3 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 4 | 4 | 1 ||* 4 | INDEX RANGE SCAN | T_N3 | 8333 | 24999 | |---------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------


Note: cpu costing is off==========================================================================SQL>SQL>SQL> analyze table t compute statistics for columns status ;Table analyzed.

SQL>SQL>SQL> get test_ans1

1 update t2 set flag='B'3 where status=2



4* and flag != 'B'SQL>SQL> @dodmlEnter .sql file name (without extension): test_ans1Enter the workspace name: updateEnter the scenario name: answer1_histDisplay results of SQL (ON/OFF)?: offCapturing statistics information...=================================================================Name of 10046 trace file: hotsos_ora_2004.trc=================================================================Explain Plan for Scenario update:answer1_hist

--------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |--------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 40000 | 117K| 22 || 1 | UPDATE | T | | | ||* 2 | TABLE ACCESS FULL | T | 40000 | 117K| 22 |--------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

2 - filter("T"."STATUS"=2 AND "T"."FLAG"'B')Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_1088.trc=================================================================

Actual Plan for Scenario update:answer1_histSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=215 r=364 w=0 time=1577867 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=4 w=0 time=72003 us)'SQL>SQL>SQL> @lsscstatList of values (Workspace)------------------------------------------------------------UPDATEWorkspace [UPDATE]:



List of values (Scenario)------------------------------------------------------------ANSWER1ANSWER1_HISTANSWER2ANSWER3PROBLEMScenario [ANSWER3]: answer1_hist

Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 4channel operations parent latch L 2checkpoint queue latch L 2,101child cursor hash table L 15Consistent RBA L 7dml lock allocation L 3hash table column usage latch L 6lgwr LWN SCN L 7library cache pin allocation L 42list of block allocation L 5messages L 39mostly latch-free SCN L 7multiblock read objects L 2post/wait queue L 4redo writing L 28session allocation L 2session idle bit L 17session timer L 1sim partition latch L 1simulator hash latch L 356simulator lru latch L 58SQL memory manager latch L 1SQL memory manager workarea list latch L 67undo global data L 11buffer is not pinned count S 210bytes received via SQL*Net from client S 1,142bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 9calls to kcmgas S 209change write time S 5CPU used by this session S 23CPU used when call started S 23



db block changes S 16,112dirty buffers inspected S 824enqueue releases S 4enqueue requests S 6free buffer inspected S 985free buffer requested S 658hot buffers moved to head of LRU S 65index scans kdiixs1 S 1messages sent S 5no work - consistent read gets S 209opened cursors cumulative S 6parse time cpu S 1parse time elapsed S 1pinned buffers inspected S 9prefetched blocks S 2recursive calls S 8redo entries S 8,011shared hash latch upgrades - no wait S 1SQL*Net roundtrips to/from client S 5switch current to new buffer S 153table scans (long tables) S 1user calls S 8write clones created in foreground S 56buffer pool L 0cache buffers chains L 64,161cache buffers lru chain L 1,957enqueue hash chains L 20enqueues L 15library cache L 150library cache pin L 82redo allocation L 8,043redo copy L 8,029row cache enqueue latch L 58row cache objects L 62shared pool L 130execute count S 6parse count (hard) S 2parse count (total) S 6redo size S 1,633,476table fetch by rowid S 1table scan blocks gotten S 207table scan rows gotten S 100,000buffer is pinned count S 0consistent gets S 215db block gets S 14,588



physical reads S 364physical writes S 0session logical reads S 14,803sorts (disk) S 0sorts (memory) S 0sorts (rows) S 0elapsed time (centiseconds) S 169

Actual Plan for Scenario UPDATE:ANSWER1_HISTSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=215 r=364 w=0 time=1577867 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=29237 op='TABLE ACCESS FULL T (cr=211 r=4 w=0 time=72003 us)'SQL>SQL>SQL>SQL> get test_ans2

1 update t2 set flag='B'3 where status=24* and flag in (select flag from flags minus select 'B' from dual )

SQL>SQL> @dodmlEnter .sql file name (without extension): test_ans2Enter the workspace name: updateEnter the scenario name: answer2_histDisplay results of SQL (ON/OFF)?: offCapturing statistics information...=================================================================Name of 10046 trace file: hotsos_ora_812.trc=================================================================Explain Plan for Scenario update:answer2_hist

----------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |----------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 200K| 1171K| 26 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 200K| 1171K| 26 || 3 | VIEW | VW_NSO_1 | 5 | 15 | 25 || 4 | MINUS | | | | || 5 | SORT UNIQUE | | 5 | 5 | |



| 6 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 5 | 5 | 1 || 7 | TABLE ACCESS FULL| DUAL | 8168 | | 11 ||* 8 | INDEX RANGE SCAN | T_N3 | 40000 | 117K| |----------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------

8 - access("T"."STATUS"=2 AND "T"."FLAG"="VW_NSO_1"."$nso_col_1")Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_2760.trc=================================================================

Actual Plan for Scenario update:answer2_histSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=411 w=0 time=1185803 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=2 w=0 time=30175 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=13335 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=13318 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=13199 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=13100 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=76 us)'STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11444 us)'SQL>SQL>SQL> @lsscstatList of values (Workspace)------------------------------------------------------------UPDATEWorkspace [UPDATE]:

List of values (Scenario)------------------------------------------------------------ANSWER1ANSWER1_HISTANSWER2ANSWER2_HISTANSWER3PROBLEMScenario [ANSWER1_HIST]: answer2_hist



Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 2checkpoint queue latch L 1,113child cursor hash table L 15Consistent RBA L 4dml lock allocation L 3hash table column usage latch L 10lgwr LWN SCN L 4library cache pin allocation L 46list of block allocation L 6messages L 17mostly latch-free SCN L 4redo writing L 14session idle bit L 16simulator hash latch L 206simulator lru latch L 54SQL memory manager workarea list latch L 4undo global data L 7buffer is not pinned count S 2bytes received via SQL*Net from client S 1,191bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 6calls to kcmgas S 1consistent gets - examination S 1CPU used by this session S 20CPU used when call started S 20db block changes S 4,421dirty buffers inspected S 292enqueue releases S 2enqueue requests S 4free buffer inspected S 296free buffer requested S 446hot buffers moved to head of LRU S 219index scans kdiixs1 S 5messages sent S 2no work - consistent read gets S 7opened cursors cumulative S 5parse time cpu S 2parse time elapsed S 2pinned buffers inspected S 3redo entries S 2,189session pga memory max S 131,072shared hash latch upgrades - no wait S 6SQL*Net roundtrips to/from client S 5table scans (short tables) S 1



user calls S 8workarea executions - optimal S 5write clones created in foreground S 1buffer pool L 0cache buffers chains L 14,833cache buffers lru chain L 972enqueue hash chains L 10enqueues L 4library cache L 173library cache pin L 82redo allocation L 2,215redo copy L 2,207row cache enqueue latch L 100row cache objects L 104shared pool L 152execute count S 5parse count (hard) S 2parse count (total) S 5redo size S 638,912table fetch by rowid S 0table scan blocks gotten S 1table scan rows gotten S 1buffer is pinned count S 2consistent gets S 16db block gets S 2,839physical reads S 411physical writes S 0session logical reads S 2,855sorts (disk) S 0sorts (memory) S 3sorts (rows) S 6,405elapsed time (centiseconds) S 141

Actual Plan for Scenario UPDATE:ANSWER2_HISTSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=15 r=411 w=0 time=1185803 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=15 r=2 w=0 time=30175 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=0 op='VIEW (cr=4 r=1 w=0 time=13335 us)'STAT #1 id=4 cnt=4 pid=3 pos=1 obj=0 op='MINUS (cr=4 r=1 w=0 time=13318 us)'STAT #1 id=5 cnt=5 pid=4 pos=1 obj=0 op='SORT UNIQUE (cr=1 r=1 w=0 time=13199 us)'STAT #1 id=6 cnt=5 pid=5 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=13100 us)'STAT #1 id=7 cnt=1 pid=4 pos=2 obj=222 op='TABLE ACCESS FULL DUAL (cr=3 r=0 w=0 time=76 us)'



STAT #1 id=8 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11444 us)'SQL>SQL>SQL>SQL> get test_ans3

1 update t2 set flag='B'3 where status=24* and flag in (select flag from flags where flag != 'B')

SQL>SQL> @dodmlEnter .sql file name (without extension): test_ans3Enter the workspace name: updateEnter the scenario name: answer3_histDisplay results of SQL (ON/OFF)?: offCapturing statistics information...=================================================================Name of 10046 trace file: hotsos_ora_3228.trc=================================================================Explain Plan for Scenario update:answer3_hist

---------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost |---------------------------------------------------------------------------| 0 | UPDATE STATEMENT | | 80000 | 312K| 2 || 1 | UPDATE | T | | | || 2 | NESTED LOOPS | | 80000 | 312K| 2 ||* 3 | INDEX FULL SCAN | SYS_IOT_TOP_29235 | 4 | 4 | 1 ||* 4 | INDEX RANGE SCAN | T_N3 | 20000 | 60000 | |---------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------


Note: cpu costing is off=================================================================Name of 10053 trace file: hotsos_ora_2200.trc=================================================================

Actual Plan for Scenario update:answer3_hist



STAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=12 r=174 w=0 time=565098 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=12 r=2 w=0 time=25717 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=9258 us)'STAT #1 id=4 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11507 us)'SQL>SQL>SQL> @lsscstatList of values (Workspace)------------------------------------------------------------UPDATEWorkspace [UPDATE]:

List of values (Scenario)------------------------------------------------------------ANSWER1ANSWER1_HISTANSWER2ANSWER2_HISTANSWER3ANSWER3_HISTPROBLEMScenario [ANSWER2_HIST]: answer3_hist

Statistic NameStatistic Type (S=stat, L=Latch) Value---------------------------------------- - --------------active checkpoint queue latch L 2checkpoint queue latch L 694child cursor hash table L 15Consistent RBA L 4dml lock allocation L 3hash table column usage latch L 15lgwr LWN SCN L 4library cache pin allocation L 40list of block allocation L 8messages L 19mostly latch-free SCN L 4redo writing L 14session idle bit L 16simulator hash latch L 177simulator lru latch L 24SQL memory manager workarea list latch L 4



transaction allocation L 2undo global data L 17buffer is not pinned count S 1bytes received via SQL*Net from client S 1,181bytes sent via SQL*Net to client S 709calls to get snapshot scn: kcmgss S 3change write time S 1consistent gets - examination S 1CPU used by this session S 14CPU used when call started S 14db block changes S 4,421dirty buffers inspected S 212enqueue releases S 2enqueue requests S 4free buffer inspected S 216free buffer requested S 208hot buffers moved to head of LRU S 441index scans kdiixs1 S 5messages sent S 2no work - consistent read gets S 6opened cursors cumulative S 5parse time cpu S 1parse time elapsed S 2pinned buffers inspected S 4redo entries S 2,189session pga memory max S 65,536shared hash latch upgrades - no wait S 6SQL*Net roundtrips to/from client S 5user calls S 8workarea executions - optimal S 4buffer pool L 0cache buffers chains L 14,332cache buffers lru chain L 636enqueue hash chains L 16enqueues L 4library cache L 151library cache pin L 76redo allocation L 2,238redo copy L 2,230row cache enqueue latch L 74row cache objects L 78shared pool L 140execute count S 5parse count (hard) S 2parse count (total) S 5redo size S 638,912



table fetch by rowid S 0table scan blocks gotten S 0table scan rows gotten S 0buffer is pinned count S 2consistent gets S 12db block gets S 2,839physical reads S 174physical writes S 0session logical reads S 2,851sorts (disk) S 0sorts (memory) S 2sorts (rows) S 6,400elapsed time (centiseconds) S 68

Actual Plan for Scenario UPDATE:ANSWER3_HISTSTAT #1 id=1 cnt=0 pid=0 pos=1 obj=0 op='UPDATE (cr=12 r=174 w=0 time=565098 us)'STAT #1 id=2 cnt=1600 pid=1 pos=1 obj=0 op='NESTED LOOPS (cr=12 r=2 w=0 time=25717 us)'STAT #1 id=3 cnt=4 pid=2 pos=1 obj=29236 op='INDEX FULL SCAN SYS_IOT_TOP_29235 (cr=1 r=1 w=0 time=9258 us)'STAT #1 id=4 cnt=1600 pid=2 pos=2 obj=29241 op='INDEX RANGE SCAN T_N3 (cr=11 r=1 w=0 time=11507 us)'SQL>SQL>SQL>SQL> @hrank updateScenario ranking for workspace update by elapsed time


0.680000 ANSWER3_HIST1.020000 ANSWER31.410000 ANSWER2_HIST1.510000 ANSWER21.690000 ANSWER1_HIST2.340000 ANSWER16.210000 PROBLEM

SQL>SQL>SQL> @diffList of values (First workspace)------------------------------------------------------------



UPDATEFirst workspace [UPDATE]:

List of values (First scenario)------------------------------------------------------------ANSWER1ANSWER1_HISTANSWER2ANSWER2_HISTANSWER3ANSWER3_HISTPROBLEMFirst scenario [ANSWER2]: answer1


List of values (Second scenario)------------------------------------------------------------ANSWER1ANSWER1_HISTANSWER2ANSWER2_HISTANSWER3ANSWER3_HISTPROBLEMSecond scenario [ANSWER3]: answer1_hist

Statistic Name UPDATE UPDATEStatistic Type (S=stat, L=Latch) ANSWER1 ANSWER1_HIST Difference---------------------------------------- - -------------- -------------- --------------checkpoint queue latch L 2,357 2,101 -256Consistent RBA L 5 7 2lgwr LWN SCN L 5 7 2list of block allocation L 6 5 -1messages L 31 39 8mostly latch-free SCN L 5 7 2multiblock read objects L 48 2 -46



redo writing L 21 28 7session timer L 0 1 1sim partition latch L 2 1 -1simulator hash latch L 464 356 -108simulator l

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