The Java Pool

Since Oracle 8i, it has been possible to write procedures, functions and other code which gets stored inside the database in the Java programming language. It has since turned out that you would be certifiably insane to do so but nevertheless, the capability remains. (Java is better utilised "in the middle tier" -that is, in an application server, rather than in the backend database itself). If you run Java code in the database itself, it needs its own unique area of memory in which to execute -and that area of memory is called the Java Pool. It can be enormous (in the gigabyte range, for example) -but if you don't run Java in the database at all (all your code is, say, PL/SQL), then it can be zero in size.