This manual documents the Enterprise Control Language (ECL). ECL has been designed specifically for working with huge sets of data. This book is designed to be both a learning tool and a reference work and is divided into the following sections: ECL Basics Addresses the fundamental concepts of ECL. Expressions and Operators Defines available operators and their expression evaluation precedence. Value Types Introduces data types and type casting. Record Structures and Files Introduces the RECORD structure, DATASET, and INDEX. Alien Data Types Defines the TYPE structure and the functions it may use. Natural Language Parsing Support Defines the patterns and functions the PARSE function may use. Reserved Keywords Defines special-use ECL keywords not elsewhere defined. Special Structures Defines the TRANSFORM, MACRO, and other structures and their use. Built-In Functions and Actions Defines the functions and actions available as part of the language. Workflow Services Defines the job execution/process control aspects of ECL. Templates Defines the ECL Template commands. External Services Defines the SERVICE structure and its use.