3 - Developing and running java in the database

Abstract

This chapter deals in developing and running java in databases. It discusses the most-used techniques for putting Java sources and/or classes in the database. It explores the purpose of exposing/mapping Java procedures, functions, their parameters, and return values to SQL, and it also illustrates the various mechanisms for invoking Java in the database. This chapter also explains the various techniques for creating or loading Java in the database, how to remove Java from the database, setting or querying environment variables or system properties, and the Java compiler within the database. Both PL/SQL and Java have the same invalidation model. When an object is changed, its dependents are marked as invalid, thus leaving them in a state where a subsequent attempt to run them will cause revalidation. It also has the same automatic recompilation model. If an object is invalid when invoked, an automatic attempt is made to revalidate. Finally the chapter concludes by discussing the various steps for developing, deploying, and running Java in the database.