Stack It And Unpack It

Stack It & Pack It Partitioning And Compression For Warehouses / VLDB Jeff Moss

Agenda ,[object Object],[object Object],[object Object],[object Object]

My Background ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

What Is Data Segment Compression ? ,[object Object],[object Object],[object Object],[object Object],[object Object]

Where Can Data Segment Compression Be Used ? ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

How Does Segment Compression Work ? Database Block Symbol Table Row Data Area Block Common Header (20 bytes) Transaction Header (24 bytes fixed + 24 bytes per ITL) Data Header (14 bytes) Compressed Data Header (16 bytes - variable ) Tail (4 bytes) 100 Call to discuss bill amount TEL NO YES 3 TEL 4 NO 5 YES 2 Call to discuss bill amount 1 100 1 2 3 4 5 101 Call to discuss new product MAIL NO N/A 8 MAIL 9 N/A 7 Call to discuss new product 6 101 6 7 8 4 9 102 Call to discuss new product TEL YES N/A 10 7 3 5 9 10 102 ID DESCRIPTION CONTACT TYPE OUTCOME FOLLOWUP Table Directory (8 bytes) Row Directory (2 bytes per row )

What Affects Compression ? ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Compression v Block Size ,[object Object],[object Object]

Compression v ITL ,[object Object],[object Object]

Compression v Number Of Columns ,[object Object],[object Object],[object Object]

Compression v PCTFREE ,[object Object],[object Object]

Compression v NDV ,[object Object],[object Object]

Compression v Column Length ,[object Object],[object Object],[object Object]

Compression v Ordering ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Uniformly distributed Colocated 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 1 1 1 2 2 2 2 3 3 3 3 4 4 4 4 5 5 5 5

Get Max Compression Order Package ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Running mgmt_p_get_max_compress_order... ---------------------------------------------------------------------------------------------------- Table : BIG_TABLE Sample Size : 10000 Unique Run ID: 25012006232119 ORDER BY Prefix: ---------------------------------------------------------------------------------------------------- Creating MASTER Table : TEMP_MASTER_25012006232119 Creating COLUMN Table 1: COL1 Creating COLUMN Table 2: COL2 Creating COLUMN Table 3: COL3 ---------------------------------------------------------------------------------------------------- The output below lists each column in the table and the number of blocks/rows and space used when the table data is ordered by only that column, or in the case where a prefix has been specified, where the table data is ordered by the prefix and then that column. From this one can determine if there is a specific ORDER BY which can be applied to to the data in order to maximise compression within the table whilst, in the case of a a prefix being present, ordering data as efficiently as possible for the most common access path(s). ---------------------------------------------------------------------------------------------------- NAME COLUMN BLOCKS ROWS SPACE_GB ============================== ============================== ============ ============ ======== TEMP_COL_001_25012006232119 COL1 290 10000 .0022 TEMP_COL_002_25012006232119 COL2 345 10000 .0026 TEMP_COL_003_25012006232119 COL3 555 10000 .0042

Pros & Cons ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Data Warehousing Specifics ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],1 - Table Compression in Oracle 9iR2: A Performance Analysis

Things To Watch Out For ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

A Funny Thing… ,[object Object],[object Object],Thanks to Julian Dyke for the block dumping information – http://www.juliandyke.com

What Is Partitioning ? ,[object Object],[object Object],[object Object],[object Object],[object Object]

Partition To Tablespace Mapping ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],P_JAN_2005 P_FEB_2005 P_MAR_2005 P_APR_2005 P_MAY_2005 P_JUN_2005 P_JUL_2005 P_AUG_2005 P_SEP_2005 P_OCT_2005 P_NOV_2005 P_DEC_2005 T_Q1_2005 T_Q2_2005 T_Q3_2005 T_Q4_2005 T_Q1_2006 P_JAN_2006 P_FEB_2006 P_MAR_2006 T_Q3_2005 Read / Write Read Only

Read Only Tablespaces ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Partition Tablespace

Why Partition ? - Performance ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],SELECT SUM(sales) FROM part_tab WHERE sales_date BETWEEN ‘01-JAN-2005’ AND ’30-JUN-2005’ Sales Fact Table * Oracle 10gR2 Data Warehousing Manual JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Why Partition ? - Manageability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Why Partition ? - Scalability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Why Partition ? - Availability ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],P_JAN_2005 P_FEB_2005 P_MAR_2005 P_APR_2005 P_MAY_2005 P_JUN_2005 P_JUL_2005 P_AUG_2005 P_SEP_2005 P_OCT_2005 P_NOV_2005 P_DEC_2005 T_Q1_2005 T_Q2_2005 T_Q3_2005 T_Q4_2005 T_Q1_2006 P_JAN_2006 P_FEB_2006 P_MAR_2006 T_Q3_2005 Read / Write Read Only

Fact Table Partitioning Transaction Date Load Date ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],07-JAN-2005 Customer 1 09-JAN-2005 15-JAN-2005 Customer 2 17-JAN-2005 January Partition February Partition 22-JAN-2005 Customer 3 01-FEB-2005 02-FEB-2005 Customer 4 05-FEB-2005 26-FEB-2005 Customer 5 28-FEB-2005 March Partition 06-MAR-2005 Customer 2 07-MAR-2005 12-MAR-2005 Customer 3 15-MAR-2005 Tran Date Customer Load Date April Partition 21-JAN-2005 Customer 7 04-APR-2005 09-APR-2005 Customer 9 10-APR-2005 07-JAN-2005 Customer 1 09-JAN-2005 15-JAN-2005 Customer 2 17-JAN-2005 21-JAN-2005 Customer 7 04-APR-2005 22-JAN-2005 Customer 3 01-FEB-2005 January Partition February Partition 02-FEB-2005 Customer 4 05-FEB-2005 26-FEB-2005 Customer 5 28-FEB-2005 March Partition 06-MAR-2005 Customer 2 07-MAR-2005 12-MAR-2005 Customer 3 15-MAR-2005 Tran Date Customer Load Date April Partition 09-APR-2005 Customer 9 10-APR-2005

Watch out for… ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],Jonathan Lewis: Cost-Based Oracle Fundamentals, Chapter 2

Partitioning Feature: Characteristic Reason Matrix    Partition Truncation     Exchange Partition    Archiving    Pruning (Partition Elimination)   Partition wise joins  Parallel DML     Local Indexes    Read Only Partitions Availability Scalability Manageability Performance Characteristic: Feature:

References: Papers ,[object Object],[object Object],[object Object],[object Object]

References: Online Presentation / Code ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Stack It And Unpack It

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