Dr. Stephan Bühne Senior Principal Technical Consultant SAP Solution Center Walldorf
O2O-Transition Oracle Transition Project New tool set for rapid transitions and reorganisations of very large databases
Available Migration methods SAP R3/LOAD SAP R3 IMIG HP/ Oracle Transition Project
Challenges for migrations Common database sizes > 1TB SAP method R3Load 400 GB/24h R3Load requires downtime of 60 h for 1 TB IMIG needs additional HW on source very consultant intensiv Reduces downtime only for large tables Minimizing downtime is essential Faster method is needed to speed up migrations
R3Load Advantages: Heterogenous DB migrations possible Long time established Disadvantages Source system must be prepared manually Very Slow process (17 GB/h up to 50 GB/h) Additional space on file system needed Creation on target size with insert operation Index creation slow
Architecture of R3Load method Source System (can be any database) R3Load Approx. 17 GB/h (calculated on overall Database size) Flat Files R3Load Target System (can be any database) (Volume: 30% Database size)
Transition Project Challenges Developing a fast and reliable method to perform an Oracle => Oracle Transition Should be finished within one normal weekend, even for very large databases Migration speed of > 200GB DB-size / hour => 4TB system is managable in one weekend Highly automated to reduce consulting effort Match the special requirements of SAP systems
Technologies O2O Method is using standard oracle methods: Oracle CTAS (Create Table As Select) Oracle Export/Import Oracle PL/SQL (on NON-HP platforms) On HP systems a HP program (TblCopy) is used for SAP Cluster/Pool Tables An automated scheduling program is used to control the transition progress
Architecture O2O Source system Oracle >= 8.1.7 PL/SQL Package (Script generator) > 200 GB/h (calculated on overall Database size) Target system Oracle >= 9.2 Large tables (> 2GB) Transferred directly over network Index Creation parallized Export Import For tables < 2GB 1 10% database size
O2O-Preparation PL/SQL Package Loaded into source DB Create subdirectories for package output Oracle 9i: Create directory command Oracle 8i: init.ora parameter UTL_FILE_DIR
Package execution PL/SQL Package (Script generator) Exec... SQL-Scripts Shell-Scripts UNDO-Scripts
O2O-Features Makes file system layout optimization more easy: Create optimal file system layout on the new IO subsystem and adjust number of datafiles and subdirectory structure of the database accordingly. Tablespaces are transformed automatically to LMTS. ASSM feature can be included also. BW-Systems are handled automatically. No limitation on numbers of partitions on tables
Package Output: Preparation of Target System sapdata1 system_1 btabd_1 File-System sapdata2 batbi_1 btabd_2 sapdata# roll_1 temp_2
O2O Database layout sapdata1 system_1 btabd_1 optimization Key values: # of sapdatas Data file size sapdata5 sapdata25 batbi_11 btabd_22 batbi_21 btabd_45 sapdata1 Included scripts for: creating the subdirectories create database create tablespaces create users/roles system_1 btabd_1 btabd_5... batbi_1 btabi_3
O2O: Database Space Fragmentation in Tablespace defragmentation Dictionary managed TBS are transferred to LMTS TBS TBS size is reduced Full database reorganisation is included
O2O-Features SAP Cluster and Pool tables are recognized automatically and will be handled in a special way (PL/SQL or TblCopy) Export dumps are limited to 2 GB or 2000 tables Parallization of index creation is computed automatically Table size is calculated either on statistical data or on DBA_SEGMENTS
O2O Optimization Based on the table size, the best transition method is choosen for a particular table. The threshold is defined by a package parameter. Large tables will be transferred directly either by CTAS, PL/SQL or TblCopy Small tables will be included in export/ import scripts The index creation on the target is optimized by using parallel query The transition process is controled and scheduled by a transistion control center software
O2O: Transition process Source Large Tables Scheduler Target CTAS, PL/SQL, TblCopy Small Tables export import transition control center Index Creation
O2O-Transition: Transition challenges Transition speed is influenced by the key parameters: IO-subsystem performance on the target IO-subsystem performance on the source Available CPU and memory on the target Size-pattern of the database Network
O2O-Transition: Size pattern of tables Size Size Duration of the Copy Process Parallization Parallization
O2O-Transition: Number of Indexes Multiple Tables + Indexes Single Table + Indexes Duration Parallization Duration
O2O: Check transition Source success Scheduler Target Comparison on object level between source and target system Control of transition process
O2O: Importing Statistics Source Scheduler Target Export statistics for User Import statistics for User Control of transition process
SAP specific tasks Once the transistion is completed, SAP specific tasks must be performed These tasks are the same, as in a R3- Load migration Once these tasks are completed, the system is fully supported by SAP
Transition FINISHED
O2O Benefits High performance data transfer between oracle databases Upgrades old systems to state of the art technology 5-6 times faster than traditional methods Reduces time efforts and project risks More than 200 GB/h transfer speed possible Method of choice for transition of large systems Even very large databases can be handled within a normal weekend Systems are fully supported by SAP after end of transition
References Hella database reorganisation on AIX with 1.2 TB Burda True64/ HP-UX Transition 17 SAP systems including BW Etinera BW-Migration 900 GB
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