PLSQL - Identifiers

PL/SQL identifiers are

• constants
• variables
• exceptions
• procedures
• cursors
• reserved words. 

Identifiers consist of a letter optionally followed by more letters, numerals, dollar signs, underscores, and number signs and should not exceed 30 characters. 

• By default, identifiers are not case-sensitive.
• So you can use number or NUMBER to represent a numeric value.
• You cannot use a reserved keyword as an identifier.

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