In this article, we will look into creating our own Aggregate Function in Oracle.
User-defined aggregates are a feature of the Extensibility Framework.It is possbile to make user define Aggregate function because of Oracle's Data Cartridge model which takes advantage of object types and other extensibility features. Inorder to create user-defined aggregate function, we need to implement a set of routines collectively referred to as the ODCIAggregate routines. It is of four types which are