We have implemented Redis in our infrastructure. Salvatore Sanfilippo, the creator of memcached, created Redis. Redis is a singular key/value data structure server and an in-memory data structure server. It is a high-performance, open-source, in-memory data structure server that is often used as a distributed key/value storage engine. Because of its speed, scalability, and low latency, Redis is frequently used as a data store alternative.
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Redis is an in-memory database with a variety of useful features. It’s commonly used for caching, storing session information, and providing fast access to frequently used data. With its high performance and built-in support for various data structures, Redis has become a standard choice for many application developers. Redis is capable of storing data as individual bytes or larger strings. You can also use it to store lists of unique identifiers or even complex records with fields separated by commas. In this article, we’ll explain everything you need to know about Redis technology and how you can use it in your own applications.
Redis (short for Relational Database) is an in-memory database that can be used as a data store, cache, or message broker. It’s written in C, runs as a standalone process on a single computer, and is capable of storing data as individual bytes or larger strings. You can also use it to store lists of unique identifiers or even complex records with fields separated by commas. Redis is often compared to an RDBMS like MySQL or PostgreSQL because it provides a way to store and access data in a database-like fashion. However, there are a few key differences between an RDBMS and Redis that make them suitable for different use cases.
Let’s assume that you’ve already downloaded and installed Redis on your computer. If not, you can follow these instructions: First, you need to download the correct version for your system. In this example, we’ll be using the 64-bit version for Windows: https://redis.io/download Now, you can install the downloaded file with the help of the “Add New Software” wizard: In the “Add New Software” wizard, you need to select “Install from a list or specific location” and then click the “Next” button. Next, you need to select “Install software from the Open Source Software Interchange” and then click the “Next” button again. At the “Select the software to install” screen, you need to select “Redis-64” and then click the “Next” button to install the software. When the installation is complete, you can click the “Finish” button.
Before we get into the specifics of working with Redis data types, you need to understand how Redis stores and retrieves data. As we mentioned earlier, Redis can store data as individual bytes or larger strings. Unlike traditional relational databases, Redis doesn’t need to parse data or create column fields in order to store it in the database. This means that certain data types won’t work in Redis – for example, dates can’t be stored as individual bytes. Redis supports a variety of data types, including strings, hashes, lists, sets, and sorted sets. Let’s take a look at each of these data types in more detail. String - Used for storing text data. Redis supports standard Base64 encoded strings if you prefer to store encrypted data. Hash - Used for storing key-value pairs of data (similar to a dictionary or map data structure). Each key maps to a single value, and data types can include strings, numbers, or other hashes. List - Used to store ordered data such as a list of log entries, blog posts, or to-do items. Each item can be accessed and removed by its position in the list. Lists can be nested – you can create a “list of lists” structure in Redis to store multiple lists. Set - Used to store unique data without any order or structure. There can only be one instance of each item in a set. Sorted Set - Used to store unique data with a sorted order. You can add items to the set, query for items based on their position in the set, or search for items based on a specific search term.
We mentioned earlier that you can store unstructured data in Redis as a string – either a single string or a “string list”. Let’s look at a few examples of how you can work with strings in Redis: - You can store a single string in Redis by calling the SET command followed by the key name and value. For example: SET myKey someValue - You can store a list of strings by calling the HMSET command followed by the key name and one or more values. For example: HMSET myKey one two three four - You can store a single string or a list of strings in a sorted set by calling the SADD command followed by the key name and value. For example: SADD myKey one two three four
Lists are useful for storing ordered data such as log entries, blog posts, to-do items, or any other records that can be accessed and removed by their position in the list. Let’s take a look at how you can work with lists in Redis: - You can store a list by calling the LPUSH command followed by the key name and a value. For example: LPUSH myList one two three four - You can retrieve a specific item from the list by calling the LRANGE command followed by the key name and an item number. For example: LRANGE myList 0 2 - You can remove an item from the list by calling the LRANGE command followed by the key name and an item number. For example: LRANGE myList 0 2 - You can retrieve a range of items from the list by calling the LTRIM command followed by the key name and an item number range. For example: LTRIM myList 0 2 4
Sets are useful for storing unique data without any order or structure. Let’s take a look at how you can work with sets in Redis: - You can store data in a set by calling the SADD command followed by the key name and a value. For example: SADD mySet one two three four - You can remove a specific item from the set by calling the SPOP command followed by the key name. For example: SPOP mySet - You can retrieve a range of items from the set by calling the SRANDOM command followed by the key name and a range (inclusive). For example: SRANDOM mySet 0 2 - You can retrieve a range of items from the set by calling the SSCAN command followed by the key name and a range (inclusive). For example: SSCAN mySet 0 2
Now that you know what Redis is and how it works, you’re ready to start using it in your own applications. In this article, we learned that Redis can store data as individual bytes or larger strings. We also learned about the various data types that Redis supports, including lists, sets, strings, and hashes. We also explored how to work with each of these data types in Redis.
