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.

Binary Large Object (BLOB)

A large object data type whose value consists of raw binary data.

character large object (CLOB)

The large object (LOB) data type whose value is composed of character data corresponding to the database character set.

is character set determined by NLS parameters?

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.

embedded object attribute

An attribute of a column 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.

index-organized table IOT

A table organized by its index.

leaf-level scalar object

An object that is not a collection and is not composed of other types.

leaf-level scalar attribute

An attribute of a leaf-level scalar object.

literal invocation

An invocation where all arguments are literals or invocations of literal methods. Arguments cannot be variables.

materialized view

A view that contains both the query and its results.

multilevel collection type

Ccollection 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.

nested table

An unordered set of data elements of the same data type.

normalize

The process of removing redundancy in data by separating the data into multiple tables.

object column

A column of user-defined types or abstract data types (ADT)s .

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 instance

An instance of an object type. Also referred to as an object.

object table

A table in which each row represents an object. See row object.

object type

The type of the object instance. It is similar to a record that has methods. Object types are user-defined.

outer table

A table that contains a nested table.

pinning

Fetching.

PL/SQL

The Oracle procedural language extension to SQL.

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.

primary key

The column or set of columns specified in the PRIMARY KEY constraint of a table.

REF

An Oracle built-in data type that encapsulates references to row objects of a specified object type.

row object

An object that is stored in a complete row in an object table.

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.

type evolution

The modification of a subtype of a type, typically using an ALTER statement.

VARRAY

An ordered set of data elements, that are of the same data type or a subtype of the declared data type.