1. prligence Empowering Intelligence Partitioning Demystified Arup Nanda Proligence, Inc. Norwalk, CT

2. prligence Empowering Intelligence What’s It Divide and Conquer The Best Thing Since Sliced Bread

3. prligence Empowering Intelligence Partition Views View Created as SELECT some fields FROM Table1 UNION ALL SELECT same fields FROM Table2 Table A Table B View

4. prligence Empowering Intelligence Problem While INSERTING Table A Table B Row1 View

5. prligence Empowering Intelligence Real Partitions Came Out with Oracle 8.0 Range Partitioned Only Partition Key Column –VALUES LESS THAN (CONSTANT) Partition A Partition B Main Table

6. prligence Empowering Intelligence Hash Partitions Where Range is Not Practical Performance Partition1 Partition2 Row1 Hash Func

7. prligence Empowering Intelligence Composite Partitioning Partitions are subdivided Range-Hash Range-List Partition1 Partition2 Subpart1 Subpart2 Subpart1 Subpart2

8. prligence Empowering Intelligence List Partitioning Similar to Range but Values are Discrete PARTITION BY LIST (STATE_CODE) ( PARTITION P1 VALUES (‘CT’,’NY’), PARTITION P2 VALUES (‘NJ’), PARTITION PM VALUES (DEFAULT) ) Multi-column not supported

9. prligence Empowering Intelligence Local Index Partitioning Schemes of Index and Table are Same Easy to Administer REBUILD part by part Table Index

10. prligence Empowering Intelligence Global Indexes Indexes That Span Across All Rows of All Partitions Typically Used to Enforce Primary Keys Index

11. prligence Empowering Intelligence Equi-Partitioning If a Table and another Table are partitioned in exactly same way with the same Partitioning Key E.g. SALES on ORDER_DATE ORDERS on ORDER_DATE TableB TableA

12. prligence Empowering Intelligence SALES

13. prligence Empowering Intelligence QTR1QTR2QTR3DEFAULT SALES PARTITIONS

14. prligence Empowering Intelligence DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 SALES PARTITIONS SUBPARTITIONS

15. prligence Empowering Intelligence DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 TAB ANALYZE

16. prligence Empowering Intelligence DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 TAB DEFAULT CUST3 CUST2 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1

17. prligence Empowering Intelligence DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 DEFAULT CUST3 CUST2 CUST1 TAB IND TABLE INDEX replace

18. prligence Empowering Intelligence DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 TAB DEFAULT CUST3 CUST2 DEFAULT CUST3 CUST2 DEFAULT CUST3 CUST2 DEFAULT QTR1QTR2QTR3DEFAULT CUST3 CUST2 IND DEFAULT CUST3 CUST2 DEFAULT CUST3 CUST2 DEFAULT CUST3 CUST2 CUST1 TABLE INDEX CUST1

19. prligence Empowering Intelligence Subpartitioning Select from a partition by SELECT … FROM TAB1 PARTITION (P1); Select from a subpartition by SELECT … FROM TAB1 SUBPARTITION (SP1); Works for Insert/Update/Delete, SQL*Loader INTO TABLE TAB1 SUBPARTITION (SP1) And Export, too TABLE=MYTAB1:SP1

20. prligence Empowering Intelligence Subpartitioning … DBA_SEGMENTS SELECT * FROM DBA_SEGMENTS WHERE TABLE_NAME = ‘TAB1’ AND PARTITION_NAME = ‘SP1’ / SEGMENT_TYPE

21. prligence Empowering Intelligence Subpartitions Subpartition Templates PARTITION BY RANGE (COL1) SUBPARTITION BY HASH (COL2) SUBAPARTITION TEMPLATE ( SUBPARTITION SP1 TABLESPACE T1, SUBPARTITION SP2 TABLESPACE T2 ) ( PARTITION P1 VALUES LESS THAN (101), PARTITION P2 VALUES LESS THAN (201), … P1_SP1, P1_SP2, P2_SP1, P2_SP2 Can’t Specify Storage (8i) Can specify Storage (9i) DBA_SUBPARTITION_TEMPLATES

22. prligence Empowering Intelligence Partition Pruning Partition Based on Date – 1 partition per quarter SELECT … FROM SALES WHERE ORDER_DATE = ‘1/1/2003’ Will search only the 2003 Q1 partion ptest1 ins_ptest1; ptest2

23. prligence Empowering Intelligence Plan_Table Revisited Relvant Columns PARTITION_START PARTITION_STOP PARTITION_ID The step id that decided the partition start and stop FILTER_PREDICATES The exact condition used to evaluate partitions

24. prligence Empowering Intelligence Dbms_xplan dbms_xplan.display( ‘plan_table’, /* plan table name */ NULL, /* statement id */ ‘BASIC’, /* format */ ‘TYPICAL’,‘ALL’,‘SERIAL’) select * from table ( )

25. prligence Empowering Intelligence Partition Wise Joins Equi-partioned tables SALES partitioned on SALES_DATE REVENUE partitioned on BOOKED_DATE SELECT … FROM SALES S, REVENUE R WHERE S.SALES_DATE = R.BOOKED_DATE REVENUESALES Partition1 Partition2 Partition3 Partition1 Partition2 Partition3 Ptest3a ptest3b

26. prligence Empowering Intelligence Partitionwise Join Hash Partitioned Tables Elimination will occur in Equality only, not in range. Ptest3ha ptest3hb

27. prligence Empowering Intelligence Character Values in Range CREATE TABLE EMPLOYEE (…………) PARTITION BY RANGE (LAST_NAME) ( PARTITION P1 VALUES LESS THAN (‘D%’), PARTITION P2 VALUES LESS THAN (‘M%’), PARTITION P3 VALUES LESS THAN (‘T%’), PARTITION PM VALUES LESS THAN (MAXVALUE) ) ptest4a, ptest4b, ins_ptest4

28. prligence Empowering Intelligence Multi-column Keys Col1 col2 --- ---- ----- 50 50 rec1 150 150 rec2 50 150 rec3 150 50 rec4 101 50 rec5 101 101 rec6 101 150 rec7 201 50 rec8 201 101 rec9 201 201 rec10 p1 p2 partition by range (col1, col2) (partition p1 values less than (101, 101), partition p2 values less than (201, 201), partition pm values less than (maxvalue, maxvalue)) ptab1 p2 pm

29. prligence Empowering Intelligence Multi-Column Decision Consider 1st Column Consider 1st Column < Boundary Value < Boundary Value = Boundary Value = Boundary Value 1st Partition Consider 2nd Column Consider 2nd Column < Boundary Value < Boundary Value 2nd Partition 3rd Partition Y N Y N Y

30. prligence Empowering Intelligence Converting to Partitioning Oracle Recommended (MetaLink Note 1070693.6) Create the partitoned table and Insert Create Table As Select (CTAS) Create Small Tables and Exchange Partitions PROBLEM : Space Requirement and Time

31. prligence Empowering Intelligence Alternatives Oracle 9i Online Redefinition –Small Downtime –Space Needed –Oracle 9i

32. prligence Empowering Intelligence Split-Split Method Create partitioned table exactly same as source table with one partition with MAXVALUE Exchange source table with this partition Split this partition at the lowest boundary Split the maximum partition at the next boundary Repeat till all partitions are created

33. prligence Empowering Intelligence Example Table NOPART COL1 NUMBER COL2 VARCHAR2(10) COL3 CHAR(2) Index IN_NOPART (COL2) Constraint CK_NOPART (COL3 IS NOT NULL) Partitioned BY RANGE (COL1) P1 LESS THAN (101) P2 LESS THAN (201) P3 LESS THAN (301) P4 LESS THAN (401) PM … (MAXVALUE) Table PART Table, Index, Constraint Name Change

34. prligence Empowering Intelligence Summary Create table part … Exchange partition pMAX with table NOPART Split partition pMAX repeatedly Drop original table nopart Rename part to no part Rename index to in_nopart Rename constraint to ck_nopart

35. prligence Empowering Intelligence Pros & Cons Space Needs – Less Redo Log Generation – Minimized Time – Less Concurrency – Higher Time – Still High Concurency – Still Low

36. prligence Empowering Intelligence Exchanging Partitions Main Table Partition p1 Subpartition sp1 Subpartition sp2 Subpartition sp3 ), … Source Table partition p1 partition p2 partition p3

37. prligence Empowering Intelligence Subpartition Statistics DBMS_STATS.GATHER_TABLE_STATS –tabname => ‘MYTABLE’ –partname => ‘P1’ – granularity => DEFAULT GLOBAL PARTITION SUBPARTITION ALL Spart1.sql

38. prligence Empowering Intelligence Statistics Collection GranularityTable Global Partition Global Partition Stats Subpart Stats GLOBALYESNO PARTITIONNOYES NO DEFAULTYES NO SUBPARTITIONNO YES ALLYES

39. prligence Empowering Intelligence Parallel Index Rebuilding –One Query Server per Partition –Slows down processing –Can’t exploit the Parallel Processing Capabilities q1q2 QC q3q4

40. prligence Empowering Intelligence Parallel Index Rebuilding DBMS_PCLXUTIL.BUILD_PART_INDEX jobs_per_batchNUMBER DEFAULT 1 procs_per_job NUMBER DEFAULT 1 tab_name VARCHAR2 idx_name VARCHAR2 force_opt BOOLEAN DEFAULT FALSE

41. prligence Empowering Intelligence The Rule Based Optimizer Invokes CBO Makes Up Statistics Don’t Use Partitioning if RBO is Used

42. prligence Empowering Intelligence Coalesce –vs- Merge Coalesce – Hash Partitions Merge – Range and List coalesce merge

43. prligence Empowering Intelligence A Real Life Case Sales Datawarehouse Several Customers Several Quarters Data Coming from Customers Irregular Frequency Data Comes Often Late

44. prligence Empowering Intelligence Datawarehouse Cust1 Cust2 Cust3 Cust4 Cust10 Cust9 Cust8 Cust7 Cust11? Cust5Cust6 DB3 DB6 DB4DB5 DB1DB2

45. prligence Empowering Intelligence Detail Table Detail Table Summary Table Summary Table Detail Table Detail Table CUST2 Problem of Irregular Data

46. prligence Empowering Intelligence CUST1 Summary tables Summary tables DETAIL TABLES CUST2 CUST1 aggregation

47. prligence Empowering Intelligence Problems Data Coming from Customers Irregularly Need to Refresh the Summary Tables when New Data Arrives Quarters are Added Continuosly Archival Requirements Vary Across Customers Quick Retrieval of Archival Needed

48. prligence Empowering Intelligence Problems contd. Summary on Summary Tables as Materialized Views Needed to be Refreshed whenever New Data Arrived Or When Data is Purged/Reinstated Customers Added and Deleted Frequently

49. prligence Empowering Intelligence Objective To Minimize Downtime for Refreshes –Incrementally Refresh –Partitioning Techniques To Add Customers Easily To Add Quarters Easily To Archive Off and Purge Easily and Atomically To Restore Archives Quickly

50. prligence Empowering Intelligence Design Varying Dimensions – –Customer –Quarter Composite Partitioning –Range (for Quarters) –List (for Customers) Local Indexes

51. prligence Empowering Intelligence Design contd… Mat Views Created As Tables First Query Rewrite and Stale Tolerated Same Partitioning as Parent Tables –Partition-Wise Joins –Partition Pruning –Partition Independence

52. prligence Empowering Intelligence cust1 Summary Table Summary Table DW View Owned by Cust Schema Temporary Table Index of Temporary Table Massaging Analyzing Filter: Where SALES_DATE is in that quarter INDEX TABLE For Customer cust1 and Quarter Q1

53. prligence Empowering Intelligence cust DW View Old Sub Partition INDEX TABLE

54. prligence Empowering Intelligence Design Each Subpartition – of Index or Table is kept in seprate tablespaces named in the format S _ _Y Q E.g. S1_CUST1_Y02Q2

55. prligence Empowering Intelligence subpartitions partitions PARENT MV1 MV2 TableSpace1TableSpace2

56. prligence Empowering Intelligence Design … MV_* Subpartitions are on the same tablespace as the parents. Subparts of MV_S1_0? are in the same TS as S1 Subparts of MV_S2_0? in S2

57. prligence Empowering Intelligence Qtr1 Qtr2Qtr3 DEF Cust1 Cust2 Cust3 DEF

58. prligence Empowering Intelligence Qtr1 Qtr2Qtr3 DEF Cust1 Cust2 Cust3 DEF

59. prligence Empowering Intelligence Qtr1 Qtr2Qtr3 DEF Cust1 Cust2 Cust3 DEF Cust4

60. prligence Empowering Intelligence Qtr1 Qtr2Qtr3 DEF Cust1 Cust2 Cust3 DEF

61. prligence Empowering Intelligence Qtr1 Qtr2Qtr3Qtr4 Cust1 Cust2 Cust3 DEF

62. prligence Empowering Intelligence Objectives Revisited To Minimize Downtime for Refreshes –Incrementally Refresh –Partitioning Techniques To Add Customers Easily To Add Quarters Easily To Archive Off and Purge Easily and Atomically To Restore Archives Quickly

63. prligence Empowering Intelligence www.proligence.com