Appendix: Terminology

String Literal: A string literal is a set of characters enclosed in single quotation marks (''); it’s interpreted as is, not treated as a keyword or command.

Wildcard characters: They are used to present one or more alphanumeric characters, The wildcard characters available for pattern search in Oracle 12c are the percent sign "%" and underscore symbol "_".

Escape Character: It indicates when wildcard symbols should be used as literals rather than translated as wildcard characters. "\"

Database Object is defined, and self-contained structure in Oracle 12C. For exmaple: Table, View, Constriant. It can be anything with a name and a defined structure.

SCHEMA indicates who own the table. if the person creating the table is also the person who owns the table, the SCHEMA can be omitted, the current username is assumed by default.

Substitution Variable in the SQL command instructs Oracle to substitute a value in place of the variable at the time the command is actually executed. "&"

PseudoColumns: data associated with table data, much like column, but not physical column stored in the database.

ROWID: the physical address of a table row.

Cardinality: to describe the level of distinct values in a table column. If a column contains many distinct values, it is described as having high cardinality.