SQL Planmanagement. unter der Lupe. DOAG Konferenz 2012, Nürnberg Jan Krüger TUI Infotec GmbH, Hannover

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1 SQL Planmanagement unter der Lupe DOAG Konferenz 2012, Nürnberg Jan Krüger TUI Infotec GmbH, Hannover

2 TUI InfoTec. Wir schreiben Geschichte. Von der IT-Abteilung des Touristikkonzerns zum international agierenden IT-Dienstleister. < seit Oktober 2011 IT Abteilung innerhalb der TUI Gründung TUI InfoTec Fokus ausschließlich auf das TUI-Geschäft über 30 internationale Konzernkunden Joint Venture Sonata 50,1 % TUI 49,9 % TUI Travel PLC übernimmt die TUI InfoTec von Sonata Software vollständig TUI InfoTec We integrate your business Page Nr.

3 TUI InfoTec. Entwicklungs- und Rechenzentren. Hannover 1 Hannover Mitarbeiter ( Ende 2012) TUI InfoTec We integrate your business Page Nr.

4 TUI InfoTec. Unsere Partner und Provider. Gemeinsam mit unseren strategischen Partnern gewährleisten wir die Umsetzung von innovativen Komplettlösungen für unsere Kunden. TUI InfoTec We integrate your business Page Nr.

5 SQL Plan Management unter der Lupe Was wollen Sie eigentlich hier? Basisarbeit Nichts bleibt ewig Adaptive Cursor Sharing Dem CBO auf die Sprünge helfen

6 Was wollen Sie eigentlich hier?

7 Warum wir Plan Management einsetzen

8 Schwierig, schwierig

9 Oder Bulletpoints? SQL> select count(*) from dba_sql_plan_baselines; 0 SQL> alter session set optimizer_capture_sql_plan_baselines=true; Session altered. SQL> select count(iata_cd) from airport where country='united States'; 1209 SQL> select count(*) from dba_sql_plan_baselines; 0 SQL> select count(iata_cd) from airport where country='united States'; 1209 SQL> select count(*) from dba_sql_plan_baselines; 1

10 Spielen

11 Set!

12 Baukasten???

13 Die Flughäfen der Welt Daten und Abbildung openflights.org

14 Unsere 1 Tabellen Applikation 1,Goroka,Goroka,Papua New Guinea,GKA,AYGA, , ,5282,10,U 2,Madang,Madang,Papua New Guinea,MAG,AYMD, , ,20,10,U 3,Mount Hagen,Mount Hagen,Papua New Guinea,HGU,AYMH, , ,5388,10,U 207,Blida,Blida,Algeria,"",DAAB, , ,535,1,N NAME CITY COUNTRY IATA_CD 1050,Banjul Intl,Banjul,Gambia,BJL,GBYD, ICAO_CD , ,95,0,N 352,Hannover,Hannover,Germany,HAJ,EDDV, , ,183,1,E 3830,Chicago Ohare Intl,Chicago,UnitedStates,ORD,KORD, , ,668,-6,A LATITUDE LONGITUDE ALTITUDE

15 Die Flughäfen der Welt Latitude Gambia Longitude Daten und Abbildung openflights.org

16 Spendieren wir ein paar Indices create index latitude_idx on airport(latitude); create index longitude_idx on airport(longitude); create index country_idx on airport(country); exec dbms_stats.gather_table_stats(null, 'AIRPORT', estimate_percent=>100, cascade=>true, method_opt=>'for ALL COLUMNS SIZE 254');

17 SQL Plan Management unter der Lupe Was wollen Sie eigentlich hier? Basisarbeit Nichts bleibt ewig Adaptive Cursor Sharing Dem CBO auf die Sprünge helfen

18 Die Baseline (dba_sql_plan_baselines) Baseline Accepted = YES Accepted = NO = YES = NO

19 Ein Statement select count(iata_cd) from airport where country= Gambia Id Operation Name E-Rows SELECT STATEMENT 1 SORT AGGREGATE 1 2 TABLE ACCESS BY INDEX ROWID AIRPORT 1 * 3 INDEX RANGE SCAN COUNTRY_IDX Predicate Information (identified by operation id): access("country"='gambia')? CBO COUNT(IATA_CD) EXEC

20 Die Baseline & der Cursorcache Cursorcache Baseline Accepted = YES Accepted = NO = YES = NO

21 Befüllen der Baseline Cursorcache Baseline Accepted = YES = YES Accepted = NO REPRODUCED=YES = NO OPTIMIZER_CAPTURE_SQL_ PLAN_BASELINES=true oder DBMS_SPM. LOAD_PLANS_FROM_CURSOR_CACHE

22 Select * from dba_sql_plan_baselines Signature Sql_handle SQL_58cd c0e Sql_text select count(iata_cd) from airport where country='gambia' Plan_name SQL_PLAN_5jmaj44922b0f45fcffbd Creator SPM_TEST Origin AUTO-CAPTURE Parsing_schema_name SPM_TEST Version Created :45:13, Last_modified Last_executed :45:13, Last_verified, Accepted, Fixed, Reproduced U.a. DBMS_SPM.CONFIGURE ( plan_retention_weeks, 53) Autopurge=YES

23 select * from table(dbms_xplan.display_sql_plan_baseline(null, 'SQL_PLAN_5jmaj44922b0f45fcffbd', 'ADVANCED')) Outline Data from SMB: /*+ BEGIN_OUTLINE_DATA INDEX_RS_ASC(@"SEL$1" "AIRPORT"@"SEL$1" ("AIRPORT"."COUNTRY")) OUTLINE_LEAF(@"SEL$1") ALL_ROWS DB_VERSION(' ') OPTIMIZER_FEATURES_ENABLE(' ') IGNORE_OPTIM_EMBEDDED_HINTS END_OUTLINE_DATA */ Plan hash value: Id Operation Name SELECT STATEMENT 1 SORT AGGREGATE 2 TABLE ACCESS BY INDEX ROWID AIRPORT * 3 INDEX RANGE SCAN COUNTRY_IDX

24 Ausführung nach einem re-parse Cursorcache? Baseline Accepted = YES Accepted = NO = YES = NO

25 SQL Plan Management unter der Lupe Was wollen Sie eigentlich hier? Basisarbeit Nichts bleibt ewig Adaptive Cursor Sharing Dem CBO auf die Sprünge helfen

26 Das Bessere ist der Feind des Guten select count(iata_cd) from airport where country='gambia' Plan hash value: Id Operation Name E-Rows SELECT STATEMENT 1 SORT AGGREGATE 1 2 TABLE ACCESS BY INDEX ROWID AIRPORT 1 * 3 INDEX RANGE SCAN COUNTRY_IDX Predicate Information (identified by operation id): access("country"='gambia')

27 Viel hilft viel! create index country_idx2 on airport(country, iata_cd); exec dbms_stats.gather_schema_stats('spm_test', estimate_percent=>100, method_opt=>'for ALL COLUMNS SIZE 254'); cascade=>true); select count(iata_cd) from airport where country='gambia';

28 Ein neuer Plan Cursorcache? Baseline Accepted = YES Accepted = NO = YES = NO

29 select * from table(dbms_xplan.display_sql_plan_baseline(null, 'SQL_PLAN_5jmaj44922b0f6d136c13', '')) SQL handle: SQL_58cd c0e SQL text: select count(iata_cd) from airport where country='gambia' Plan name: SQL_PLAN_5jmaj44922b0f6d136c13 Plan id: : YES Fixed: NO Accepted: NO Origin: AUTO-CAPTURE Plan hash value: Id Operation Name Rows Bytes Cost (%CPU) Time SELECT STATEMENT (0) 00:00:01 1 SORT AGGREGATE 1 14 * 2 INDEX RANGE SCAN COUNTRY_IDX (0) 00:00: Predicate Information (identified by operation id): access("country"='gambia')

30 Evolution der Pläne Cursorcache Baseline Accepted = YES Accepted = NO = YES = NO

31 Darwinismus in der Datenbank var c clob; exec :c := DBMS_SPM.EVOLVE_SQL_PLAN_BASELINE(); print c verify => YES commit => YES Auch einzelne Pläne anwählbar.

32 Evolve SQL Plan Baseline Report Inputs: SQL_HANDLE =, PLAN_NAME = TIME_LIMIT = DBMS_SPM.AUTO_LIMIT VERIFY = YES COMMIT = YES Plan: SQL_PLAN_5jmaj44922b0f6d136c Plan was verified: Time used,141 seconds. Plan passed performance criterion: 1,5 times better than baseline plan. Plan was changed to an accepted plan. Baseline Plan Test Plan Stats Ratio Execution Status: COMPLETE COMPLETE Rows Processed: 1 1 Elapsed Time(ms):,1,085 1,18 CPU Time(ms): 0 0 Buffer Gets: 3 2 1,5 Physical Read Requests: 0 0 Physical Write Requests: 0 0 Physical Read Bytes: 0 0 Physical Write Bytes: 0 0 Executions: 1 1 Number of plans verified: 1 Number of plans accepted: 1

33 Evolution der Pläne Cursorcache Baseline Accepted = YES Accepted = NO = YES = NO

34 Reparse nach CBO-Kosten Cursorcache? Baseline Accepted = YES Accepted = NO = YES = NO

35 Doch kein schöner Plan - Disabled Cursorcache Baseline Accepted = YES = YES variable n number exec :n :=DBMS_SPM.ALTER_SQL_PLAN_BASELINE Accepted = NO (NULL, 'SQL_PLAN_5jmaj44922b0f6d136c13', 'enabled', 'NO'); = NO Automatischer Aufräumjob!

36 Doch kein schöner Plan - Fixed Cursorcache Baseline Accepted = YES = YES Accepted = NO keine Aufnahme neuer Pläne für dieses SQL = NO variable n number exec :n :=DBMS_SPM.ALTER_SQL_PLAN_BASELINE (NULL, 'SQL_PLAN_...', fixed, YES');

37 drop index country_idx; Cursorcache? Baseline Accepted = YES Accepted = NO = YES = NO

38 drop index country_idx; drop index country_idx2; Cursorcache? (FULL TABLE SCAN) Baseline Accepted = YES Accepted = NO = YES = NO (INDEX RANGE SCAN)

39 Überraschung! (INDEX RANGE SCAN) select * from table(dbms_xplan.display_sql_plan_baseline(null, 'SQL_PLAN_5jmaj44922b0f45fcffbd', '')) Id Operation Name Rows Bytes Cost (%CPU) Time SELECT STATEMENT (0) 00:00:01 1 SORT AGGREGATE 1 14 * 2 TABLE ACCESS FULL AIRPORT (0) 00:00:

40 Die Tücke der Signature Schema SPM_TEST Table AIRPORT Index country_idx Select Schema SPM_TEST Table AIRPORT Select Cursorcache INVALID_UNAUTH! Baseline Accepted = YES Accepted = NO = YES

41 SQL Plan Management unter der Lupe Was wollen Sie eigentlich hier? Basisarbeit Nichts bleibt ewig Adaptive Cursor Sharing Dem CBO auf die Sprünge helfen

42 Breitengrad von -90 bis 90 Latitude Longitude Daten und Abbildung openflights.org

43 Adaptive Cursor Sharing ohne SPM cleanout baseline alter session set optimizer_capture_sql_plan_baselines=false; exec :n := &1;? select count(iata_cd) from airport where latitude > :n; Id Operation Name SELECT STATEMENT 1 SORT AGGREGATE * 2 TABLE ACCESS FULL AIRPORT Id Operation Name SELECT STATEMENT 1 SORT AGGREGATE 2 TABLE ACCESS BY INDEX ROWID AIRPORT * 3 INDEX RANGE SCAN LATITUDE_IDX

44 Adaptive Cursor Sharing ohne SPM cleanout baseline alter session set optimizer_capture_sql_plan_baselines=false; exec :n := &1; select count(iata_cd) from airport where latitude > :n;? N = Count(iata_cd) FULL TABLE SCAN FULL TABLE SCAN 90 0 FULL TABLE SCAN FULL TABLE SCAN 80 1 FULL TABLE SCAN 85 0 FULL TABLE SCAN FULL TABLE SCAN 98 0 INDEX RANGE SCAN LATITUDE_IDX

45 Adaptive Cursor Sharing ohne SPM 2 N = Count(iata_cd) 85 0 INDEX RANGE SCAN LATITUDE_IDX FULL TABLE SCAN FULL TABLE SCAN 80 1 FULL TABLE SCAN 80 1 FULL TABLE SCAN 82 1 INDEX RANGE SCAN LATITUDE_IDX 81 1 FULL TABLE SCAN 82 1 INDEX RANGE SCAN LATITUDE_IDX 81 1 FULL TABLE SCAN 82 1 INDEX RANGE SCAN LATITUDE_IDX

46 Adaptive Cursor Sharing mit SPM alter session set optimizer_capture_sql_plan_baselines=true; exec :n := &1; select count(iata_cd) from airport where latitude > :n; N = Count(iata_cd) FULL TABLE SCAN FULL TABLE SCAN 90 0 FULL TABLE SCAN FULL TABLE SCAN 80 1 FULL TABLE SCAN 92 0 FULL TABLE SCAN FULL TABLE SCAN 98 0 FULL TABLE SCAN

47 Alles stabil mit SPM und ACS Cursorcache (FULL TABLE SCAN) Baseline Accepted = YES Accepted = NO = YES = NO

48 Es hätte auch anders kommen können Cursorcache (INDEX RANGE SCAN) Baseline Accepted = YES Accepted = NO = YES = NO EVOLVE verify= YES geht manchmal schief

49 EVOLVE verify= NO Cursorcache? N > Baseline Accepted = YES Accepted = NO = YES = NO Hint BIND_AWARE bzw. NO_BIND_AWARE nicht Teil der Baseline

50 SQL Plan Management unter der Lupe Was wollen Sie eigentlich hier? Basisarbeit Nichts bleibt ewig Adaptive Cursor Sharing Dem CBO auf die Sprünge helfen

51 Einen schlechten Plan patchen Cursorcache Baseline Accepted = YES Accepted = NO = YES = NO SQL> SQL>alter DBMS_SPM.ALTER_SQL_PLAN_BASELINE session set optimizer index_cost_adj=1; SQL>alter (NULL, session <plan_name>, set enabled, NO ) optimizer_capture_sql_plan_baselines=true; SQL>select DBMS_SPM.EVOLVE_SQL_PLAN_BASELINE... from ; SQL>/ (2 (plan_name=>.. ) x ausführen!)

52 Einen schlechten Plan hinten Cursorcache Baseline Accepted = YES = YES Accepted = NO select /*+ LEADING( ) INDEX( ) */ from ; = NO DBMS_SPM. LOAD_PLANS_FROM_CURSOR_CACHE (sql_id=>'7vw4wyf41cd3a', sql_handle=>'sql_7a94c5d1c909a52b');

53 Einen schlechten Plan hinten Cursorcache Baseline Accepted = YES Accepted = NO = YES ALTER_SQL_PLAN_BASELINE = NO DBMS_SPM. LOAD_PLANS_FROM_CURSOR_CACHE (sql_id=>'7vw4wyf41cd3a', sql_handle=>'sql_7a94c5d1c909a52b');

54 Was noch zu erwähnen wäre exec DBMS_SPM.CREATE_STGTAB_BASELINE ('BASETAB', JKUSER', 'USERS'); var n number; exec :n := DBMS_SPM.PACK_STGTAB_BASELINE ('BASETAB', 'JKUSER'); var n number; exec :n := DBMS_SPM.UNPACK_STGTAB_BASELINE ('BASETAB', 'JKUSER');

55 Hau wech! set serveroutput on variable n number; declare bl dba_sql_plan_baselines%rowtype; i number := 0; begin for bl in (select plan_name from dba_sql_plan_baselines) loop i := i + DBMS_SPM.DROP_SQL_PLAN_BASELINE(NULL, bl.plan_name); end loop; :n := i; end; / print :n;

56 Fazit Empfehlenswertes Feature, aber kein Allheilmittel! Immer besser, man weiß, was man tut! Plan Evolution mit Change-Control und verify=no. Dedizierter Backout einfach und schnell.

57 Fragen

58 Set!