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Jonathan Lewis EOUG Jun 2000 Execution Plans Agenda What are execution plans Where do you find execution plans Key mechanisms of execution Understanding.

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Presentation on theme: "Jonathan Lewis EOUG Jun 2000 Execution Plans Agenda What are execution plans Where do you find execution plans Key mechanisms of execution Understanding."— Presentation transcript:

1 Jonathan Lewis EOUG Jun 2000 Execution Plans Agenda What are execution plans Where do you find execution plans Key mechanisms of execution Understanding a complex plan Conclusion

2 Jonathan Lewis EOUG Jun 2000 Execution Plans What are execution plans Show me all clients accounts which are holding at least one position andhave no unsettled positions

3 Jonathan Lewis EOUG Jun 2000 Execution Plans What are execution plans Select * from accounts a where exists (select null from holdings h1 where h1.account = a.account and av_qty != 0 ) and not exists (select null from holdings h2 where h2.account = a.acount and unset_qty = 0 )

4 Jonathan Lewis EOUG Jun 2000 Execution Plans What are execution plans SELECT STATEMENT FILTER TABLE ACCESS FULL ACCOUNT TABLE ACCESS BY ROWID HOLDING INDEX RANGE SCAN HOLD_IX1 NON-UNIQUE TABLE ACCESS BY ROWID HOLDING INDEX RANGE SCAN HOLD_IX1 NON-UNIQUE

5 Execution Plans Where do plans come from ? selectep1.v1, ep2.v2, ep3.n2 fromep3,ep2,ep1 where( ep3.v1 = 'TV Region1' orep3.v2 = 'Newspaper2' ) andep2.n1 = ep3.n1 andep2.n2 = ep3.n2 andep1.n1 = ep2.n1;

6 Jonathan Lewis EOUG Jun 2000 Execution Plans Autotrace SQL*Plus set autotrace on set autotrace on explain set autotrace traceonly explain set autotrace traceonly statistics

7 Execution Plans Autotrace 0 SELECT STATEMENT Optimizer=FIRST_ROWS (c,c,b) 1 0 HASH JOIN (c,c,b) 2 1 TABLE ACCESS (FULL) OF 'EP1' (c,c,b) 3 1 NESTED LOOPS (c,c,b) 4 3 TABLE ACCESS (BY INDEX ROWID) OF 'EP3' (c,c,b) 5 4 BITMAP CONVERSION (TO ROWIDS) 6 5 BITMAP OR 7 6 BITMAP INDEX (SINGLE VALUE) OF 'EP3_BI1' 8 6 BITMAP INDEX (SINGLE VALUE) OF 'EP3_BI2' 9 3 TABLE ACCESS (BY INDEX ROWID) OF 'EP2' (c,c,b) 10 9 INDEX (UNIQUE SCAN) OF 'EP2_PK' (UNIQUE)

8 Jonathan Lewis EOUG Jun 2000 Execution Plans Explain Plan explain plan set statement_id = userenv(‘sessionid’) for sql_statement; select from plan_table start with connect by order by

9 Execution Plans Explain Plan SELECT STATEMENT (first_rows) (c,c,b) HASH JOIN (c,c,b) TABLE ACCESS (analyzed) EP1 (full) (c,c,b) NESTED LOOPS (c,c,b) TABLE ACCESS (analyzed) EP3 (by index rowid) (c,c,b) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) (c,c,b) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

10 Jonathan Lewis EOUG Jun 2000 Execution Plans tkprof alter session set sql_trace true; tkprof {file stem} {file stem}\ explain=userid/password\ sort=\(options\)

11 Execution Plans tkprof (1) 301HASH JOIN 200 TABLE ACCESS FULL EP1 303 NESTED LOOPS 304 TABLE ACCESS BY INDEX ROWID EP3 304 BITMAP CONVERSION TO ROWIDS 2 BITMAP OR 2 BITMAP INDEX SINGLE VALUE 303 TABLE ACCESS BY INDEX ROWID EP2 606 INDEX UNIQUE SCAN (object id 21464)

12 Execution Plans tkprof (2) 0SELECT STATEMENT GOAL: HINT: FIRST_ROWS 301 HASH JOIN 200 TABLE ACCESS GOAL: ANALYZED (FULL) OF 'EP1' 303 NESTED LOOPS 304 TABLE ACCESS GOAL: ANA (BY IND RID) OF 'EP3' 304 BITMAP CONVERSION (TO ROWIDS) 2 BITMAP OR 2 BITMAP INDEX (SINGLE VALUE) OF 'EP3_BI1' 2 BITMAP INDEX (SINGLE VALUE) OF 'EP3_BI2' 303 TABLE ACCESS GOAL: ANA (BY IND RID) OF 'EP2' 606 INDEX GOAL: ANA (UNIQ SC) OF 'EP2_PK' (UNIQ)

13 Execution Plans Trace file id=1 cnt=301 pid=0 pos=0 obj=0 op='HASH JOIN ' id=2 cnt=200 pid=1 pos=1 obj=21461 op='TABLE ACCESS FULL EP1 ' id=3 cnt=303 pid=1 pos=2 obj=0 op='NESTED LOOPS ' id=4 cnt=304 pid=3 pos=1 obj=21465 op='TABLE ACCESS BY IND RID EP3 ' id=5 cnt=304 pid=4 pos=1 obj=0 op='BITMAP CONVERSION TO ROWIDS ' id=6 cnt=2 pid=5 pos=1 obj=0 op='BITMAP OR ' id=7 cnt=2 pid=6 pos=1 obj=21466 op='BITMAP INDEX SINGLE VALUE ' id=8 cnt=2 pid=6 pos=2 obj=21467 op='BITMAP INDEX SINGLE VALUE ' id=9 cnt=303 pid=3 pos=2 obj=21463 op='TABLE ACCESS BY IND RID EP2 ' id=10 cnt=606 pid=9 pos=1 obj=21464 op='INDEX UNIQUE SCAN '

14 Jonathan Lewis EOUG Jun 2000 Execution Plans Key mechanisms of execution Data access methods Data manipulation methods

15 Jonathan Lewis EOUG Jun 2000 Execution Plans Data access select * from dept where dname = 'SALES'; TABLE ACCESS FULL DEPT

16 Jonathan Lewis EOUG Jun 2000 Execution Plans Data access select empno from emp where mgr = 7698; INDEX RANGE SCAN NON-UNIQUE EMP_FK_MGR The index is (mgr,empno)

17 Jonathan Lewis EOUG Jun 2000 Execution Plans Parent and Child select * from dept where deptno = 10; IdPidPlan 10TABLE ACCESS BY ROWID DEPT 21 INDEX UNIQUE SCAN UNIQUE DPT_PK

18 Jonathan Lewis EOUG Jun 2000 Execution Plans Parent, child, and grandchild select * from emp where deptno = 10; IdPidPlan 10TABLE ACCESS BY ROWID EMP 21 BITMAP CONVERSION TO ROWIDS 32 BITMAP INDEX SINGLE VALUE EMP_FK_DPT

19 Jonathan Lewis EOUG Jun 2000 Execution Plans Parent with two children select* fromemp wherejob='SALESMAN' andsal=1250; IdPidPos Plan 101 TABLE ACCESS BY ROWID EMP 211 AND-EQUAL 321 INDEX RANGE SCAN NON-UNIQUE EMP_JOB 422 INDEX RANGE SCAN NON-UNIQUE EMP_SAL

20 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select max(sal),count(*) from emp; SORT AGGREGATE TABLE ACCESS FULL EMP

21 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select deptno,max(sal) from emp group by deptno; SORT GROUP BY TABLE ACCESS FULL EMP

22 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select deptno,max(sal) from emp group by deptno; SORT GROUP BY (NOSORT) TABLE ACCESS BY ROWID EMP INDEX RANGE SCAN NON-UNIQUE EMP_FK_DP

23 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select max(empno) from emp where mgr = 7698; The index is emp_fk_mgr (mgr,empno) sort (aggregate) first row index (range scan (min/max)) of emp_fk_mgr

24 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select deptno,max(sal) from emp group by deptno having max(sal) > 3000; FILTER SORT GROUP BY TABLE ACCESS FULL EMP

25 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select mgr,count(*) from emp where job = 'SALESMAN' group by mgr order by count(*) desc; SORT ORDER BY SORT GROUP BY TABLE ACCESS BY ROWID EMP INDEX RANGE SCAN NON-UNIQUE EMP_FK_JOB

26 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where job='SALESMAN' or deptno = 10; CONCATENATION TABLE ACCESS BY ROWID EMP BITMAP CONVERSION TO ROWIDS BITMAP INDEX SINGLE VALUE EMP_FK_DPT TABLE ACCESS BY ROWID EMP INDEX RANGE SCAN NON-UNIQUE EMP_FK_JOB

27 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where job='SALESMAN' or deptno = 10; CONCATENATION TABLE ACCESS BY ROWID EMP

28 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where job='SALESMAN' or deptno = 10; CONCATENATION TABLE ACCESS BY ROWID EMP BITMAP CONVERSION TO ROWIDS BITMAP INDEX SINGLE VALUE EMP_FK_DPT TABLE ACCESS BY ROWID EMP

29 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where job='SALESMAN' or deptno = 10; CONCATENATION TABLE ACCESS BY ROWID EMP TABLE ACCESS BY ROWID EMP INDEX RANGE SCAN NON-UNIQUE EMP_FK_JOB

30 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where job='SALESMAN' or deptno = 10; Id Pid Ps Plan CONCATENATION TABLE ACCESS BY ROWID EMP BITMAP CONVERSION TO ROWIDS BITMAP INDEX SINGLE VALUE EMP_FK_DPT TABLE ACCESS BY ROWID EMP INDEX RANGE SCAN NON-UNIQUE EMP_FK_JOB

31 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where job='SALESMAN' or job = 'CLERK' INLIST ITERATOR TABLE ACCESS BY ROWID EMP INDEX RANGE SCAN NON-UNIQUE EMP_FK_JOB

32 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Data handling select * from emp where exists ( select null from projects prj where prj.empno = emp.empno and prj.date_completed is null ) FILTER TABLE ACCESS FULL EMP TABLE ACCESS BY ROWID PROJECTS INDEX RANGE SCAN NON-UNIQUE PRJ_FK_EMP

33 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms: Joins Nested Loops Sort Merge Hash

34 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Nested Loop Nested Loops [The first set of data] [The second set of data]

35 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Nested Loop Nested Loops Table scan FULL the red pack Table scan FULL the blue pack

36 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Nested Loop Nested Loops Table access by rowid DEPT Index unique scan DPT_PK Table access by rowid EMP Index range scan EMP_FK_DPT

37 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Sort Merge Merge Join [The first sorted set of data] [The second sorted set of data]

38 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Sort Merge Merge Join Sort join Table access full DEPT Sort join Table access full EMP

39 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Sort Merge Merge Join Index Range Scan DPT_IDX Sort join Table access full EMP

40 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Hash Hash [The first set of data] [The second set of data]

41 Jonathan Lewis EOUG Jun 2000 Execution Plans Mechanisms:Hash Hash Table access FULL DEPT Table access FULL EMP

42 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Nested Loops [The first set of data] [The second set of data]

43 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Nested Loops Table access by rowid DEPT Index unique scan DPT_PK Table access by rowid EMP Index range scan EMP_FK_DPT

44 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Table access by rowid SALGRADE Index range scan SAL_PK

45 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Nested Loops Table access by rowid DEPT Index unique scan DPT_PK Table access by rowid EMP Index range scan EMP_FK_DPT Table access by rowid SALGRADE Index range scan SAL_PK

46 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Nested Loops Table access by rowid REGION Index unique scan REG_PK Table access by rowid DEPT Index unique scan DPT_FK_REG

47 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Nested Loops Table access by rowid REGION Index unique scan REG_PK Table access by rowid DEPT Index unique scan DPT_FK_REG Table access by rowid EMP Index range scan EMP_FK_DPT Table access by rowid SALGRADE Index range scan SAL_PK

48 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Hash [The first set of data] [The second set of data]

49 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Hash Table scan full Medium_table Table scan full Large_table

50 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Table scan full Small_table

51 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Hash Table scan full Medium_table Table scan full Large_table Table scan full Small_table

52 Jonathan Lewis EOUG Jun 2000 Execution Plans Understanding a complex plan Hash Table scan full Small_table Hash Table scan full Medium_table Table scan full Large_table

53 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

54 Execution Plans Explain Plan - top down SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

55 Execution Plans Explain Plan NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

56 Execution Plans Explain Plan TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value)

57 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

58 Execution Plans Explain Plan - Bottom up SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

59 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

60 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

61 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

62 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

63 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

64 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

65 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

66 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

67 Execution Plans Explain Plan SELECT STATEMENT (first_rows) HASH JOIN TABLE ACCESS (analyzed) EP1 (full) NESTED LOOPS TABLE ACCESS (analyzed) EP3 (by index rowid) BITMAP CONVERSION (to rowids) BITMAP OR BITMAP INDEX EP3_BI1 (single value) BITMAP INDEX EP3_BI2 (single value) TABLE ACCESS (analyzed) EP2 (by index rowid) INDEX (analyzed) UNIQUE EP2_PK (unique scan)

68 Jonathan Lewis EOUG Jun 2000 Execution Plans Conclusion Execution plans are important How much effort do you take Break complex plans down


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