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Object oriented databases. By Claudia Buder. 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. About object oriented databases.
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Object oriented databases By Claudia Buder Programming
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
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
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 = "13504 4th Avenue South"; } txn.commit(); db.close(); } //exception handling would go here ...
Database application • Data collection applications • Information analysis applications • Applications handling BLOBs
ODB using architectures • Stand-alone architecture • Architecture with existing data sources
When an ODBMS should be used • Business need • High performance • Complex data • Reduction of development and maintenance costs
Resources • http://www.service-architecture.com/object-oriented-databases/ • http://www.sei.cmu.edu/str/descriptions/oodatabase.html • http://www.cisco.com/univercd/cc/td/doc/product/rtrmgmt/cw2k4mw/mwfm201/mwfmtop/33oql.html
Thanks for your attention ! Questions ???