The document discusses techniques for evolutionary database development in an agile team. It recommends that the database administrator (DBA) work closely with other roles to iteratively refactor the database schema through small, frequent changes. It also emphasizes automated testing and deployment of database changes to safely evolve the database design over time.

1. Evolutionary Database Development

2. Software Development Process is Changing © ThoughtWorks 2009 Fix / Integrate $ Test Code Design Specifications Use Cases / Functional Specs Requirements Gathering Project Plan/Estimation $ $ $ $ Level Stories Vision & High- Iteration Release

6. Refactoring “ A disciplined way to make change to your source code to improve its design, making it easier to work with” Martin Folwer

11. A Story

13. Refactoring database schema Introduce transition period for SAFTY

14. Never get rid of old schema immediately Data sync in real time

15. What we did in this project Legacy DB NEW DB FlatFile Triger SystemNameID Newvalue OldValue columnName Read Data Near real Time Read Data systemName SystemNameID(PK) SystemLogin … systemName_log SystemNameID(PK) OperDatetime Account AccountID(PK) AccountName SystemNameID Isdelete

17. The process of database refactoring

20. Put test scripts into CI Put verification scripts into CI Run verification scripts in production often, be aware of production data

23. Delcare row_num number:=0; Begin for c_CN in (select MessId,C1,C2 from contactInfo a left join CI_Mig_log b on a.Messid=b.messid where flag=0) update contactNote set contactNote=c_CN.c1, contactId=c_CN.c2 where Messid=c_CN.Messid update CI_MIG_log f set f.flag=1 where messid=c_Cn.MessId row_num:=row_num+1; if mod(row_num,1000)=0 then commit; end if; End loop; Cancel it if there is no enough resource for migration Migration ContactInfo Messid(pk) C1 C2 … ContactNote ContactNoteId(pk) ContactNote ContactId MessId CI_Mig_log MessID(PK) Flag

25. Put them under configuration management control CREATE TABLE money ( eek NUMBER ); //Test for… DB DDL Insert into AA(mydata) Values(11); Meta Data Delete from .. DML Create index optimization Merge into Data Migration Tests Installation scripts

26. Configuration of DB project Database project under version control Tiny db backup Deltascripts of dbdeploy For defining db objects which depends on schema For data onetime migration For data sync For checking dirty data Tool exclusively for database project other scripts…

27. Database Deployment An automated process is needed to make the process of upgrading out-of-date databases

29. Management DB deploymnet DB Deploy - http://dbdeploy.com/

34. Batch file: libraryantant.exe –buildfile:evovle.build –D:rebuildDB -logfile:build.txt Shared to devs Do what we want by just One Command

36. Q&A