1. © 2008 Quest Software, Inc. ALL RIGHTS RESERVED. Managing Database Change with Data Modeling Bert Scalzo, PhD Bert.Scalzo@Quest.com

2. 2 Bert Scalzo … Database Expert & Product Architect for Quest Software Oracle Background: Worked with Oracle databases for over two decades (starting with version 4) Work history includes time at both “Oracle Education” and “Oracle Consulting” Academic Background: Several Oracle Masters certifications BS, MS and PhD in Computer Science MBA (general business) Several insurance industry designations Key Interests: Data Modeling Database Benchmarking Database Tuning & Optimization "Star Schema" Data Warehouses Oracle on Linux – and specifically: RAC on Linux Articles for: Oracle’s Technology Network (OTN) Oracle Magazine, Oracle Informant PC Week (eWeek) Articles for: Dell Power Solutions Magazine The Linux Journal www.linux.com www.orafaq.com

3. 3 Books by Bert … Coming in 2009 … 2 nd Edition Coming Soon Out Now …

4. Agenda Define Database Change Management Examine Common DBA Options for Managing Database Structural Changes Examine the World of Modeling Why Data Modeling Often Makes Sense as the Change Management Methodology Examples using Toad Data Modeler

5. Presentation Objectives To demonstrate: Why a change management system is essential That database structural changes can be accomplished in many ways How data modeling tools can be an essential part of database change management The advantages of data modeling in change management

6. What is Database Change Management? …Ensuring that the source and target databases are in sync after changes to the environment: Development database Test database(s) Production database Distributed databases Replicated databases Task is harder than you may think!

7. Common Database Change Management Tasks Create/Drop tables Add/Drop table columns Resize table columns Add/Drop index columns Reorder index columns Add/Drop column constraints Modify column constraint logic Add/Drop table & index partitions Add/Drop object grants and roles Resize or Relocate database objects

8. Change Management Can Be Tedious… Some database sync tasks require lots extra, indirect work (depending on the Oracle server version) –Drop table columns –Resize (i.e. shorten) table columns –And a few others … Therefore, the DBA must –Be aware of all these scenarios –Write extended alteration scripts –E.G. copy table, copy data, rename, grants

9. Common Change Management Options Direct to Database One Way DDL Scripts One Way DDL Scripts + Version Control Two Way DDL Scripts Two Way DDL Scripts + Version Control DB Schema Managers

10. #1: Direct to Database Pros: Method of least resistance (i.e. easy) Manually alter the database directly Often use highly visual tools like TOAD DBA and OEM Requires no extra tools (no extra $ or learn curve) Cons: The database is the Master Totally ad-hoc database mods can be problematic Extended alters require lots manual DBA time History of structural changes is lost

11. #2: One Way DDL Scripts Pros: An Old Timer’s favorite Manually edit a Master DDL script Requires no extra tools (no extra $ or learn curve) Cons: The DDL Script is the Master Can forget & thus loose ad-hoc database mods Extended alters require lots manual DBA time History of structural changes is lost

12. #3: One Way DDL Scripts + Version Control Pros: Manually edit a version of Master DDL script Requires source control tool (free on UNIX) Addresses history shortcoming of prior method Cons: The DDL Script is the Master Can forget & thus loose ad-hoc database mods Extended alters require lots manual DBA time

13. #4: Two Way DDL Scripts Pros: Manually create DDL script based upon compare Requires DDL extract tool (can be SQL script) Cons: The DDL Script is the Master Can miss & over-ride ad-hoc database mods Extended alters require lots manual DBA time History of structural changes is lost

14. #5: Two Way DDL Scripts + Version Control Pros: Manually create DDL script based upon compare Requires DDL extract tool (can be scripts) Requires diff & source control tools (free on UNIX) Addresses history shortcoming of prior method Cons: The DDL Script is the Master Can miss & override ad-hoc database mods Extended alters require lots manual DBA time

15. #6: DB Schema Managers Pros: Automatically create DDL script or directly apply selected changes (i.e. sync) based upon compare Requires DB comp & sync tool, but then no other tools Addresses history shortcoming of prior methods Extended alters as easy as any other modification Cons: Disconnect between data models and database

20. Data Modeling as a Change Management Methodology Works off the meta-data documenting the business requirements (i.e. the true source code so to speak) Requires using just one tool – the data modeling tool Eliminates having multiple steps and branch points Sometimes picture of what’s changed is more readily apparent and understandable than the alternatives By very nature, keeps database & its requirements in sync!

21. The World of Modeling … Identify all data & relationships - E/R (Entity/Rel’ship) diagrams - DB independent view Business Rules? Conceptual Data Modeling (CDM – E/R) Physical Data Modeling (PDM) Business Process Modeling (BPM) Object-Oriented Modeling (OOM - UML) DB-specific model Reverse engineer existing DB Create/Update DB from model Data Warehouse Modeling DBA DB Developer DB Architect Bus. Analyst Data Architect Data Analyst System Architect System Analyst App Developer End-user IT Partner/Liaison Business Analyst Support for all UML diagrams - Analyze requirements - Design application Reverse/forward engineer code Improve process efficiency Define/document Bus. Processes - create correct and complete application requirements

22. #6: Data Modeling Tools Toad Data Modeler Pros: Automatically create DDL script or directly apply selected changes (i.e. sync) based upon compare Requires DB compare & sync tool, but then no other tools Addresses history shortcoming of prior methods Extended alters as easy as any other modification No disconnect between data models and database

23. Handle Like Programming Code

24. Compare & Sync Combinations Can compare & sync –Logical to Logical –Logical to Physical –Physical to Logical –Physical to Physical –Script to Physical –Database to Physical –Database to Database –Version to Version

25. MOVIES Data Model

26. Here we go … “Best laid plans of mice and men” Real life is not as rigid or structured as we plan Thus even when adopting a data modeling change management approach, two way compare/sync will still be critical (need to catch exceptions to method) In following demo: –Will change some live database objects using Toad (e.g. alter table, create table, drop table) –Will change some source code or data modeling items (e.g. alter entity, create entity, drop entity) –See how modeling tool can find and fix these!

35. Parting Thoughts Data modeling can be an invaluable method for managing and addressing change in your DB environments There are many other issues data modeling can address: –Modeling accurate business requirements –Transforming logical into physical models –Breaking data models into sub-models –Round-trip Engineering: Conceptual -> Physical Model compare and sync Physical Model -> Database compare and sync –Repository-based collaborative modeling –Horizontal and Vertical Partitioning –Data Warehousing (Star Schema design) –Object-Relational Mapping

36. Presenter: Bert Scalzo: Bert.Scalzo@Quest.comBert.Scalzo@Quest.com Questions and Answers … Thank You