How to Migrate your Database to Oracle Exadata. Noam Cohen, Oracle DB Consultant, E&M Computing

Transcription

1 How to Migrate your Database to Oracle Exadata Noam Cohen, Oracle DB Consultant, E&M Computing

2 Who am I Working with Oracle Since 2000 Versions g Consulting on all areas from Infrastructure to Application Development And now Exadata [email protected]

3 Agenda Migration Considerations Migration Strategy Physical Logical

4 Agenda Migration Considerations Migration Strategy Physical Logical

5 Migration Considerations Oracle Exadata Synergy between Hardware and Software: Smart Scans Storage Indexes Hybrid Columnar Compression Smart Flash Cache over Flash PCI High Speed InfiniBand Backbone

6 Migration Considerations So how do you migrate to Exadata Machine? Same as you d migrate to a traditional Oracle machine. Minimal downtime is a major consideration. BUT Never compromise Best Practice Configurations

7 Migration Considerations Best Practice Considerations: Hybrid Columnar Compression. Smart Scan VS. Index Scan. ORDER BY tables for better usage of Storage Indexes. ASM Diskgroups 4MB AU Size. Large Extents (8MB) for Large Segments.

8 Migration Methods Methods Overview Physical Migration Data remains in datafiles (block-for-block) Most methods are whole database migration Generally more restrictive Logical Migration Data unloaded from source, loaded into Exadata database w/ SQL Easier to migrate subset Easier to implement structural best practices Generally less restrictive

9 Migration Methods Generally speaking: Data Warehouse Typical Strategy: Change Structure (remove indexes, reorder tables etc.) Change Storage (new compression, optimize extent sizing) Change Platform (Big to Little Endian). OLTP Typical Strategy: Structure intact Migration method: 1 st : Physical 2 nd : Logical Migration method: 1 st : Logical 2 nd : Physical

10 Agenda Migration Considerations Migration Strategy Physical Logical

11 Physical Migration Data remains in datafiles(block-for-block) Database extent sizes remain the same Most methods whole database migration (except TTS) Inherit legacy database configuration indexes, MVs, no compression Stricter requirements Platform and version changes restricted

12 Physical Migration Best practice challenged Suboptimal sizing Migrate unnecessary objects Objects can be recreated post migration, but Why not use logical method in the first place?

13 Physical Migration Methods at a Glance: ASM Rebalance to Exadata Storage Connect Exadata storage to existing database nodes ADD grid disks to existing ASM disk groups, DROP legacy storage from existing ASM disk groups Partition roll-in, roll-out to Exadata Storage Connect Exadata storage to existing database nodes Only load into newly created partitions on Exadata storage Drop old partitions from traditional storage Data Guard Physical Standby Create Physical Standby on Sun Oracle Database Machine Data Guard switchover

14 Physical Migration Methods at a Glance: Data Guard Physical Standby Create Physical Standby on Sun Oracle Database Machine Data Guard switchover Optionally Upgrade to 11.2 (Note# ) Transportable Database (Note: ) RMAN CONVERT DATABASE ON TARGET to generate scripts. Transfer datafiles to Exadata Storage and Run scripts. Transportable Tablespace(TTS) Build empty 11.2 Exadata database TTS export source system metadata Transfer files to Exadata (CONVERT if source system big endian) TTS import metadata into Exadata database

15 Physical Migration Method When to Use ASM rebalance Add Exadata storage to existing 11.2 Linux x86-64 database that uses ASM w/ 4MB AU Partition roll-in/out Add Exadata storage to existing 11.2 Linux x86-64 database Data Guard Physical Standby Transportable database Linux source on 11.2, archiving and LOGGING Little endian source on 11.2 Transportable tablespaces Big endian source >= 10.1 Little endian source>=10.1, <11.2

16 Agenda Migration Considerations Migration Strategy Physical Logical

17 Logical Migration Data unloaded from source, loaded into Exadata database w/ SQL Move only the user data Best practices can be added 4MB ASM AU size set for new disk groups Large extents (8MB) for large database segments Table compression, if desired Partitioning (added or changed), if desired

18 Logical Migration Methods at a Glance: Data Guard Logical Standby Create logical standby on 11.2 Sun Oracle Database Machine Change table storage characteristics, as desired (Note: ) Data Pump Unload/Load Data Guard switchover Optionally combine with Database Upgrade (Note # ) GoldenGate/ Streams Create and upgrade replica on Sun Oracle Database Machine Stop apply Implement best practices on replica (e.g. unload, recreate, reload) Start apply to catch up Disconnect users from primary, reconnect to Sun Oracle Database Machine Data Pump Create Exadata database Import user data into Exadata using Data Pump Network mode -Direct import from source via dblink File mode-export to dump file(s), transfer file(s), Import

19 Logical Migration Methods at a Glance: Data Pump Create Exadata database Import user data into Exadata using Data Pump Network mode -Direct import from source via dblink File mode-export to dump file(s), transfer file(s), Import CTAS / IAS Create Exadata database CTAS or IAS From external tables in DBFS staging area From dblink to source database

20 Logical Migration Method Data Guard Logical Standby Oracle GoldenGate/ Streams Data Pump CTAS / IAS When to Use Rolling database upgrade requirement Table storage characteristics will be changed Minimal downtime requirement Different source platform Data type restriction with other methods Initial bulk load

21 Migration Methods In practice: Current DWsusually not on Linux x86-64 and not running 11g, so most physical methods eliminated Most DWsreplaced by Exadata are running either Oracle on big-endian UNIX, or competitor (e.g. DB2,Netezza,Teradata) Customers only want tables with user data in order to implement new database configuration determined during testing

22 Migration Methods Most common methods used thus far: Combination for staged migration CTAS/IAS or Data Pump for the initial bulk load into Exadata while source remains in use Perform daily loads (external tables) into both source and Exadata Initially users serviced by source database Move users over to Exadata Stop daily load into source

23 Questions? Noam Cohen