Programming 1 Object oriented databases By Claudia Buder

2 Content About OODB Transparent persistence  Lack of impedance mismatch  How to access data Database application Navigation with an object database ODB using architectures When an ODBMS should be used

3 About object oriented databases Integration of database capabilities with object programming language capabilities makes database objects appear as programming language objects Most used query language OQL Uses also OOA and OOD

4 Transparent persistence

5 Lack of impedance mismatch

6 Data access: e.g. Java import org.odmg.*; import java.util.Collection; Implementation impl = new com.vendor.odmg.Implementation(); Database db = impl.newDatabase(); Transaction txn = impl.newTransaction(); try { db.open("addressDB", Database.OPEN_READ_WRITE); txn.begin(); // perform query OQLQuery query = new OQLQuery( "select x from Person x where x.name = \"Doug Barry\""); Collection result = (Collection) query.execute(); Iterator iter = result.iterator(); // iterate over the results while ( iter.hasNext() ) { Person person = (Person) iter.next(); // do some addition processing on the person (now shown) // now traverse to the address object and update its value person.address.street = " th Avenue South"; } txn.commit(); db.close(); } //exception handling would go here...

7 Database application Data collection applications Information analysis applications Applications handling BLOBs

8 Navigation with an object database

9 ODB using architectures Stand-alone architecture Architecture with existing data sources

10 When an ODBMS should be used Business need High performance Complex data Reduction of development and maintenance costs

11 Resources architecture.com/object-oriented- databases/ architecture.com/object-oriented- databases/ database.html database.html oduct/rtrmgmt/cw2k4mw/mwfm201/mwfmt op/33oql.html oduct/rtrmgmt/cw2k4mw/mwfm201/mwfmt op/33oql.html

12 Thanks for your attention ! Questions ???