Skip to Main Content
Using SQLite
book

Using SQLite

by Jay A. Kreibich
August 2010
Intermediate to advanced content levelIntermediate to advanced
526 pages
23h 39m
English
O'Reilly Media, Inc.
Content preview from Using SQLite

Introduction to Modules

Virtual tables are typically used to link the SQLite database engine to an alternate data source. There are two general categories of virtual tables: internal and external. There aren’t any implementation differences between the categories, they just provide a rough way to define a module’s functionality.

Internal Modules

Internal modules are self-contained within the database. That is, the virtual table acts as a fancy front-end to more traditional database tables that are created and maintained by the virtual table module. These back-end tables are sometimes known as shadow tables. Most importantly, all the data used by the module is still stored within the database file. These types of modules typically provide a specialized type of indexing or lookup feature that is not well suited to the native database indexes. Internal virtual tables may require multiple shadow tables to efficiently operate.

The two largest modules included in the SQLite distribution (FTS3 and R*Trees) are both internal style modules. Both of these modules create and configure several standard tables to store and index the data they’ve been asked to maintain.

Generally, internal modules are used to improve or extend the data manipulation facilities of a database. In most cases, an internal virtual table isn’t doing anything an SQL developer couldn’t do on their own, the module is just making it easier or faster (or both). Internal modules often play the role of an abstract “smart view” ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Learning SQL, 3rd Edition

Learning SQL, 3rd Edition

Alan Beaulieu
High Performance MySQL, 4th Edition

High Performance MySQL, 4th Edition

Silvia Botros, Jeremy Tinley

Publisher Resources

ISBN: 9781449394592Errata PageSupplemental Content