Book excerpt: The Berkeley DB Book is intended to be a practical guide to the intricacies of Berkeley DB; an in-depth analysis of the complex design issues which are often covered in terse footnotes in the dense Berkeley DB reference manual. It explains the technology at a higher level and also covers the internals with generous code and design examples. Berkeley DB is becoming the database of choice for appliance makers and for in memory cache of large scale applications like search engines and high traffic web sites.