q For Mortals Version 3: An Introduction to q Programming

Q for Mortals Version 3 is a thorough presentation of the q programming language and an introduction to the kdb+ database. It is a complete rewrite of the original Q for Mortals that is current with q3.3. The presentation is derived from classes taught by the author at international financial institutions over the last decade. It is a series of tutorials based on q snippets intended to be entered interactively into the q console by the reader. The text takes its subject seriously but not itself. Technical explanations are augmented by mathematical observations, references to general programming concepts and other programming languages, and bad jokes. Coding style recommendations and advice to avoid gotchas appear liberally throughout. Examples are as simple as they can be but no simpler. Chapter 1, Q Shock and Awe, provides a piquant panorama of the power of q and its dazzling zen-like nature. Chapter 2 describes the base data types of q. Chapter 3 discusses lists, the fundamental data structure of q Chapter 4 presents the basic operators. Chapter 5 introduces dictionaries, which associate keys and values. Chapter 6 presents an in-depth description of functions and q's constructs for functional programming. Chapter 7 demonstrates transforming data from one type to another. Chapter 8 introduces tables and keyed tables, the fundamental data structures for kdb. Chapter 9 describes q-sql and all the methods to manipulate tables. Chapter 10 presents ways to control execution of q programs. Chapter 11 covers file and interprocess communication I/O Chapter 12 describes workspace organization and management. Chapter 13 discusses system commands and command line parameters. Chapter 14 serves as an introduction to the kdb+ database. Chapter A has a complete rundown of the built-in functions. Chapter B lists common error messages. A cross-referenced index closes the book.