IBM DB2 9.7 for Linux, UNIX, and Windows Storage Optimization

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1 IBM DB2 9.7 for Linux, UNIX, and Windows Storage Optimization Compression options with SAP Applications regarding > Space Savings > Performance Benefits > Resource Impact Thomas Rech, Hans-Jürgen Moldowan, Andreas Christian, Waldemar Gaida IBM SAP DB2 Center of Excellence Thomas Rech, IBM Hans-Juergen Moldowan, IBM IBM Corporation

2 Important Disclaimer THE INFORMATION CONTAINED IN THIS PRESENTATION IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY. WHILE EFFORTS WERE MADE TO VERIFY THE COMPLETENESS AND ACCURACY OF THE INFORMATION CONTAINED IN THIS PRESENTATION, IT IS PROVIDED AS IS, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED. IN ADDITION, THIS INFORMATION IS BASED ON IBM S CURRENT PRODUCT PLANS AND STRATEGY, WHICH ARE SUBJECT TO CHANGE BY IBM WITHOUT NOTICE. IBM SHALL NOT BE RESPONSIBLE FOR ANY DAMAGES ARISING OUT OF THE USE OF, OR OTHERWISE RELATED TO, THIS PRESENTATION OR ANY OTHER DOCUMENTATION. NOTHING CONTAINED IN THIS PRESENTATION IS INTENDED TO, OR SHALL HAVE THE EFFECT OF: CREATING ANY WARRANTY OR REPRESENTATION FROM IBM (OR ITS AFFILIATES OR ITS OR THEIR SUPPLIERS AND/OR LICENSORS); OR ALTERING THE TERMS AND CONDITIONS OF THE APPLICABLE LICENSE AGREEMENT GOVERNING THE USE OF IBM SOFTWARE IBM Corporation

3 Trademarks IBM, the IBM logo, ibm.com, AIX and DB2 are trademarks of International Business Machines Corp., registered in many jurisdictions worldwide. Other product and service names might be trademarks of IBM or other companies. A current list of IBM trademarks is available on the Web at Linux is a registered trademark of Linus Torvalds in the United States, other countries, or both. Windows is a trademark of Microsoft Corporation in the United States, other countries, or both. UNIX is a registered trademark of The Open Group in the United States and other countries. SAP, SAP NetWeaver, SAP Business Information Warehouse, SAP BW, SAP NetWeaver BW and other SAP products and services mentioned herein are trademarks or registered trademarks of SAP AG in Germany and in several other countries. Other company, product and service names may be trademarks or service marks of others IBM Corporation

4 Agenda Options for Storage Savings with IBM DB2 for UNIX, Linux, and Windows Overview of storage savings with DB2 compression Test results with Index compression Additional Options for Storage Efficiency IBM Corporation

5 What customers want to know about DB2 9.7 Storage Optimization What is the recommended approach to deploy DB2 compression? How much storage can be actually saved with the different types of SAP applications? How do the different types of DB2 compression affect system performance? How does DB2 compression affect utilization of hardware resources like CPU, memory, and IO? IBM Corporation

6 DB2 9.7 Storage Optimization Options DB2 with SAP offers several techniques to compress data Value Compression (not discussed here) Backup Compression (not discussed here) Row Compression Deferred Table Creation Index Compression New with DB2 9.7 Temporary Table Compression LOB Inlining + Row Compression New with DB2 9.7 New with DB IBM Corporation

7 DB2 Row Compression Uncompressed table RCLNT GL_SIRID RLDNR RRCTY RVERS RYEAR RTCUR RUNIT DRCRK POPER DOCCT DOCNR DOCLN RBUKRS RPRCTR RHOART BWART A DEM S 1 A A DEM S 1 A A DEM S 1 A A DEM S 1 A A DEM S 1 A BLART Compression dictionary x 01C 8A,0,0,1995,DEM,,S,1,A F 67t 1000, x 01C 21 1 F 67t x 01C 21 2 F 67t x 01C 21 3 F 67t x 01C 22 1 F 67t x 01C 22 2 F 67t 0 Common sequences of consecutive bytes in rows are replaced with symbols. Compressed table IBM Corporation

8 Compressing Tables Enable Row Compression Create a new table with the COMPRESS YES option Alter an existing table with the COMPRESS YES option Compressing Data Table Reorganization (offline) Dictionary creation with DB2 INSPECT (online) DB2 Automatic Dictionary Creation (ADC) Tools R3load with COMPRESS (optionally with sampling): During SAP Installation / Migration. Refer to html?Open DB6CONV table move (online / offline): SAP note Report /ISIS/ZCOMP: SAP note SAP DBA Cockpit IBM Corporation

9 Enabling Compression Online with DB6CONV Integrated into SAP GUI Batch support via SAP scheduling IBM Corporation

10 Enabling DB2 Row Compression Tables for Table Compression Dependency between number of compressed tables and corresponding storage savings. Storage Savings (%) Compression Rule of thumb for selection of tables for compression: Select all tables which are larger than 1 of the total DB size and exclude SAP Tableclusters from the list Tableclusters typically do not compress very well as they are already compressed by SAP. Largest N Tables compressed IBM Corporation

11 Space Savings with DB2 Row Compression The table shows compression results Overall database size DB2 vs. Other: SAPBI Source (GB) DB2 Compressed (GB) Compression Ratio (%) Comment 2305, ,00 41, , ,00 30,97 931,00 589,00 36, , ,00 19,22 739,00 594,00 19, ,00 715,00 44,27 SAP ERP Source (GB) DB2 Compressed (GB) Compression Ratio (%) 3686, ,80 52, , ,52 47,52 129,00 81,00 37, ,00 690,00 50, ,00 474,00 63,98 * 971,00 432,00 55,51 * 1171,00 670,00 42, , ,00 45,63 660,00 373,00 43,48 652,00 377,00 42,18 195,00 78,00 60,00 * Percent value indicates the percentage of saved space. Both, the DB2 and the source database have been fully reorganized. Comparisons with not fully reorganized databases are marked with * IBM Corporation

12 DB2 Index Compression Introduced with DB2 9.7 Comprises 3 different techniques to compress Indexes Variable slot directory RID list compression Prefix Compression DB2 automatically selects a combination of the best compression algorithms for each index IBM Corporation

13 DB2 Index Compression Variable Slot Directory Slot Directory Page Header AAA,1,ZX 001, 002, 004 Saved Space AAA,1,ZY 005,007,008,009,010,012,013 BBB,1,ZY 021, 022, 023 BBB,1,ZZY 014,017 In uncompressed indexes, the slot directory is pre-allocated with a fixed size With index compression, the slot directory has a variable size IBM Corporation

DB2 Index Compression RID List Compression Compression Examples: 022 = 021+1 023 = 021+1+1 017 =

With RID list compression, instead of storing each RID explicitly, only the first RID of a key

14 DB2 Index Compression RID List Compression Compression Examples: 022 = = = In non-unique indexes, key values may have multiple record identifiers (RIDs). With RID list compression, instead of storing each RID explicitly, only the first RID of a key value is stored. All subsequent RIDs are referenced by a delta offset to its predecessor IBM Corporation

15 DB2 Index Compression Prefix Compression Compression Index key values are stored in sorted order within index pages. It is very likely that adjacent key values have a common prefix. Instead of repeating these prefixes multiple times, in compressed indexes these repeating patterns are stored only once inside the index page IBM Corporation

16 Compressing Indexes Enable Index Compression: When a table on DB2 9.7 is created with the COMPRESS YES option, all its indexes will also be created with the compression option. Create an index on DB2 9.7 with the COMPRESS YES option For existing Indexes, compression can be enabled with the ALTER INDEX <SAP-SCHEMA>.<INDEX-NAME> COMPRESS YES statement Compression-enabled existing Indexes are compressed by either Reorganizing them Dropping and re-creating them IBM Corporation

17 DB2 Index Compression Compression Results Test Scenario SAP ECC 6.0 IDES SAP NetWeaver 7.1 for banking services from SAP SAP NetWeaver BW 7.0 DB size uncompressed 159 GB 103 GB 1640 GB DB size compressed 108 GB 41 GB 890 GB Compression rate data 29% 69% 49% Compression rate index 43% 37% 33% Storage savings with row compression only 18% 50% 34% Storage savings with data and index compression. 31,7% 59,9% 45,7% Additional savings with Index Compression 13,7% 9,9% 11,7% IBM Corporation

18 SAP Banking Performance Test Results 1,08 9,00 1,06 8,84 8,92 1,07 8,90 8,80 Performance Factor 1,04 1,02 1,00 8,42 1,00 1,03 8,70 8,60 8,50 8,40 Throughput (DS/sec) Dialog Processing Batch Processing 8,30 0,98 8,20 0,96 No Compression Data Compression 8,10 Data+Index Compression IBM Corporation

19 SAP BW 7.0 Query Results Runtime of Queries Time (Seconds) Query A Query B Query C Query D DB2 9.7 cold DB2 9.7 warm DB2 9.7 Data Compression cold DB2 9.7 Data Compression warm DB2 9.7 Data + Index Compression cold DB2 9.7 Data + Index Compression warm DB2 DPF with 4 logical partitions, 320 MB bufferpool and 2 CPU IBM Corporation

20 DB2 Index Compression Performance Results Test Scenario with Performance and Resiurce Usage SAP NetWeaver 7.1 for banking services from SAP - Dialog SAP NetWeaver 7.1 for banking services from SAP - Batch SAP NetWeaver BW Query Performance with data compression + 4% +2,5% +9,2% Performance with data + index compression + 6% +6% +7,8% USR + SYS CPU with data + index compression +3% +3% +5% IO WAIT CPU with data + index compression -2% -4,5% -8% IBM Corporation

21 Temporary Table Compression Dictionary based approach, similar to row compression Is automatically enabled with the DB2 Storage Optimization Feature license No need for user intervention DB2 automatically decides whether it makes sense to compress temporary tables Monitoring via db2pd db2pd -db hjm -temptable System Temp Table Stats: Number of System Temp Tables : 1 Comp Eligible Sys Temps : 1 Compressed Sys Temps : 1 Total Sys Temp Bytes Stored : Total Sys Temp Bytes Saved : Total Sys Temp Compressed Rows : Total Sys Temp Table Rows: : IBM Corporation

22 DB2 for SAP - Virtual tables Empty tables are created as view and materialized only when needed. INSERT, UPDATE, DELETE MERGE LOCK TABLE CREATE TRIGGER ALTER TABLE VOLATILE ALTER TABLE ADD column ALTER TABLE ALTER column SQL0150, SQL0156 Create Table: CREATE TABLE + CREATE INDEX + CREATE PRIMARY KEY + Recreate depending objects CREATE INDEX ALTER TABLE ADD PRIMARY KEY DROP TABLE ALTER TABLE DROP PRIMARY KEY SQL0150, SQL0156 Change View Definition: DROP VIEW + CREATE VIEW with modified view text TRUNCATE TABLE SQL3193 Ignore error DROP TABLE SQL0159 DROP VIEW CREATE VIEW "TDATASET" AS SELECT * FROM ( VALUES ( CAST ( NULL AS VARCHAR(9)), CAST ( NULL AS VARCHAR(39)), CAST ( NULL AS VARCHAR(90) ), CAST ( NULL AS VARCHAR(24)), CAST ( NULL AS VARCHAR(24)), CAST ( NULL AS VARCHAR(3)), CAST ( NULL AS VARCHAR(396)), CAST ( NULL AS VARCHAR(3)), CAST ( NULL AS VARCHAR(3)), CAST ( NULL AS VARCHAR(36) ), CAST ( NULL AS VARCHAR(24) ), CAST ( NULL AS VARCHAR(18) ), CAST ( NULL AS VARCHAR(36)), CAST ( NULL AS VARCHAR(24)), CAST ( NULL AS VARCHAR(18) ) ) ) AS " TDATASET " ( "MANDT", "FIELD", "CATT", "ID_DATAGRP", "SET_NR", "SPRSL", "VALUE", "NAME_CHANGE", "INACTIVE", "LUSER", "LDATE", "LTIME", "FUSER ", "FDATE", "FTIME" ) WHERE 1 = 2 --DDL_TABLE CREATE TABLE "TDATASET" ("MANDT" S APDB6VARCHAR(000003) DEFAULT '000' NOT NULL, "FIELD" SAPDB6VARCHAR(000013) DEFAU LT ' ' NOT NULL, "CATT" SAPDB6VARCHAR(000030) DEFAULT ' ' NOT NULL, "ID_DATAGRP". More information: da0bb5abf IBM Corporation

23 DB2 for SAP - Virtual tables Up to 65% of all tables of a SAP applications can be empty The deferred table feature is transparent for SAP applications and tools IBM Corporation

24 DB2 for SAP - Virtual tables Enablement also during Migration unsing the DEF_CRT' Option with R3load. Empty tables consume system resources, for example for Automatic Runstats, Automatic Reorg, and Monitoring jobs IBM Corporation

25 DB2 for SAP LOB Inlining Large Objects (LOBs) are stored in a different location than their base table. Link via a LOB descriptor DB2 9.7 introduced the functionality to inline smaller LOBs as part of a table, with the following advantages DB2 ROW compression applicable on inlined LOBs Inlined LOBs are buffered in DB2 bufferpools Reduced space allocation SAP support for DB2 9.7 and Kernel >= 7.00 based systems with a recent version of the DBSL. New data types are introduced for LCHR and LRAW fields For existing installations that were upgraded to DB2 9.7, one needs to copy tables (e.g. via DB6CONV) to translate to new data types and to enable Inlining More Information: Enabling DB2 for LUW 97's LOB Inlining in an SAP Environment f e-2c10-49b4-978fa1771ed IBM Corporation

26 Summary DB2 with row compression is signifcantly smaller than other database plattforms. For SAP ERP it typically saves between 40+% For SAP BW it saves between 20% and 40% DB2 index compression provides additional overall space savings between ~10% and 20% DB2 row compression improves performance: 2,5% to 4% with OLTP workload up to 30% with SAP BW queries DB2 compression increases CPU utilization (+3% to +6%) but reduces I/O wait time (-2% to -8%) DB2 compression drastically reduces both read and write I/O IBM Corporation

Deep Dive Into Storage Optimization When And How To Use Adaptive Compression. Thomas Fanghaenel IBM Bill Minor IBM

Deep Dive Into Storage Optimization When And How To Use Adaptive Compression Thomas Fanghaenel IBM Bill Minor IBM Agenda Recap: Compression in DB2 9 for Linux, Unix and Windows New in DB2 10 for Linux,