This is the first in a series of posts about Redis, a key-value
database and open source project created by Salvatore
Sanfilippo. Most web applications are built on a relational
database, and the key-value database (if used at all) is a
volatile cache. My goal is to show that Redis is a suitable
replacement for a relational database and an exciting and
powerful new technology on which to build web applications. I’ll
start with setup and basic commands; continue with lists, sets,
and some fancier stuff like key expiration; and finish with a
simple Ruby application that will demonstrate the covered
topics. Redis is the coolest bit of software I’ve seen in ages
and I hope this series helps to spread the word and get more
people to try it. What Is Redis? Redis is a key-value database.
Unlike a relational database, which is comprised of tables
containing columns of data definitions and rows of data, a key-
value database stores values, each of which is referenced by a
unique key. To get a value out of the database,