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Introduction to Redis
Redis is one of most known and used NoSQL databases among developers. Being open sourced it is equipped with over 20000 stars in GitHub and it’s found here. Redis is written in C and is mainly supported for Linux and related operating systems, but there are few ways to run Redis on Windows.
Let’s look at what Redis is used for and why Redis is different from other NoSQL databases.
NoSQL Databases and Redis
Well contrary to popular belief, NoSQL actually mean ‘Not only SQL’.
Most of these databases doesn’t exactly define database structure like tables nor support queries such as SQL SELECT. NoSQL allows less restrictions on schema as data is mostly stored in JSON objects.
As shown in above table we can see that NoSQL databases can also be classified too. Each of these categories are for different use cases.
Here Redis is key-value database as shown. Each value in the store is mapped by a key. These values can vary from each other and doesn’t follow any particular structure. However no value can be retrieved unless key is known.
From Redis creators…
Redis is an open source (BSD licensed), in-memory data structure store, used as a database, cache and message broker. It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs and geospatial indexes with radius queries. Redis has built-in replication, Lua scripting, LRU eviction, transactions and different levels of on-disk persistence, and provides high availability via Redis Sentinel and automatic partitioning with Redis Cluster.
As mentioned Redis is in-memory store where the data is isn’t written to disk but kept in volatile RAM. This in-memory feature makes extremely fast access to data and therefore Redis is frequently used as cache and as secondary database to support primary database. However some persistence…
