What data types can be stored in Redis?

What data types can be stored in Redis?

Redis supports 5 types of data types.

• Strings. Redis string is a sequence of bytes.
• Hashes. A Redis hash is a collection of key value pairs.
• Lists. Redis Lists are simply lists of strings, sorted by insertion order.
• Sets. Redis Sets are an unordered collection of strings.
• Sorted Sets.

Where Redis data is stored?

-memory
All Redis data resides in-memory, in contrast to databases that store data on disk or SSDs. By eliminating the need to access disks, in-memory data stores such as Redis avoid seek time delays and can access data in microseconds.

What is Redis datatype?

Strings are the most basic kind of Redis value. Redis Strings are binary safe, this means that a Redis string can contain any kind of data, for instance a JPEG image or a serialized Ruby object. Append to strings with the APPEND command. Use Strings as a random access vectors with GETRANGE and SETRANGE.

What is a Redis command?

redis-cli is the Redis command line interface, a simple program that allows to send commands to Redis, and read the replies sent by the server, directly from the terminal.

Why is Redis so fast?

The reasons for the high performance of redis are as follows: Memory storage: redis uses memory (in memory) storage, without disk IO overhead. Single thread implementation: redis uses a single thread to process requests, avoiding the cost of thread switching and lock resource contention between multiple threads.

What kind of data structure does Redis use?

In Redis, the key part of the key-value pair is a string as well. Databases using this type of data structure are often referred to as string-to-string key-value stores. With all the data in a single object, string operations in Redis are extremely fast.

Why is Redis not a plain key value store?

Redis is not a plain key-value store, it is actually a data structures server, supporting different kinds of values. What this means is that, while in traditional key-value stores you associated string keys to string values, in Redis the value is not limited to a simple string, but can also hold more complex data structures.

How is a Redis set different from a list?

A Redis set is an unordered collection of unique strings. As sets are not ordered, you cannot remove items from the front or end of the index as with lists. However, the strings are unique, and there is no possibility that multiple instances of the same item appear within a set.

What are the names of the Redis CLI commands?

redis – cli: runs a command line interface utility to interact with Redis. redis – benchmark: checks Redis performance. redis – check – aof and redis – check – dump: used for the rare cases when there are corrupted data files. We are going to be using the redis – server and redis – cli executable frequently.