NoSQL

Redis is an open-source, in-memory key-value data store. Depending on the needs of your application, there may be cases where you’ve set a key but you know you will want to delete it later on after a certain amount of time has passed. This tutorial explains how to set keys to expire, check how long a key has until it will expire, and cancel a key’s expiration setting.

Sets in Redis are collections of strings stored at a given key. When held in a set, an individual record value is referred to as a member. Unlike lists, sets are unordered and do not allow repeated values. This tutorial explains how to create sets, retrieve and remove members, and compare the members of different sets.

Redis allows you to plan a sequence of commands and run them one after another, a procedure known as a transaction. It’s impossible for clients to run commands while a transaction block is being executed, ensuring that the transaction is treated as a single isolated operation. This tutorial goes over how to how to execute and cancel transactions, and also includes some information on pitfalls commonly associated with transactions.

In Redis, sorted sets are a data type similar to sets in that both are non repeating groups of strings. The difference is that each member of a sorted set is associated with a score, allowing them to be sorted or ranked from the smallest score to the greatest. This tutorial explains how to create sorted sets, retrieve and remove their members, and create new sorted sets from existing ones.