Glossary
atomically null object
An object whose value is NULL
is called atomically null. An atomically null object is different from an object that has null values for all its attributes.
character large object (CLOB)
The large object (LOB) data type whose value is composed of character data corresponding to the database character set.
column object
An object that is stored as a column of a relational database table (as opposed to an object table). A column object can also be an attribute of another object. A column object is also known as a stored inline object or an embedded object.
dynamic method dispatch
A method call that is dispatched at run-time to the nearest method implementation when there are multiple implementations of the same method using overriding.
literal invocation
An invocation where all arguments are literals or invocations of literal methods. Arguments cannot be variables.
multilevel collection type
Collection types whose elements are collection types, either directly or indirectly.
multiset operators
An operator that combines elements of two nested tables into a single nested table.
object identifier
Identifier for a row object which can be either system-generated (default) or based on a primary key using the CREATE
TABLE
statement.
object type
The type of the object instance. It is similar to a record that has methods. Object types are user-defined.
polymorphism
Allows handling data types and methods generically using the same interface. In polymorphic overriding, subtypes redefine a method they have inherited. In polymorphic overloading, there may be several versions of the same method, with different parameters.
REF
An Oracle built-in data type that encapsulates references to row objects of a specified object type.
specializing
Adding new attributes or methods to a subtype that the parent supertype does not have, or changing the implementation of a method or methods.
stored procedure
A PL/SQL block that is stored in the database and can be executed from an application.
substitutability
A supertype is substitutable if one of its subtypes can substitute or stand in for it in a variable or column whose declared type is the supertype.