What are Redis databases and what are the benefits?

The vast majority of a modern IT infrastructure is based on efficient hardware and optimal data storage - information needs to be quickly available in a format understandable to external programs. Redis serves this purpose as an In-Memory Database (IMDB), which differs in many ways from traditional formats like MySQL and its variants MariaDB, as well as processing via MySQLi as a PHP plugin and InnoDB or MyISAM as storage subsystem (Engine). Redis - the acronym stands for Remote Dictionary Server - is not only a "Not only SQL" (NoSQL) database with a non-relational approach instead of fixed tables, but it also avoids file-based storage, opting instead to store data directly in the main memory (RAM).

What sets Redis apart from relational databases?

Relational databases like MySQL or MariaDB use a tabular structure, particularly dividing information based on their position - column and row - and hierarchically organising them. In NoSQL databases like Redis, however, the connections are made "horizontally" between individual entries. This does not mean an independent, isolated arrangement of individual data pairs - instead, Redis and other representatives like Apache Cassandra, CouchDB, or MongoDB form a flexible structure where individual entries can be linked to numerous other data records.

Both approaches offer specific advantages and disadvantages to consider when choosing a system. A problem with relational databases is the steadily decreasing efficiency with increasing size or workload, which requires higher computing power due to indexing all documents as demand grows. The primary issue with NoSQL databases like Redis, on the other hand, lies in the low guarantee of continuous and error-free data consistency that applications must consider. Accessing individual data records outside of a parent unit can lead to significant errors in the worst case, the origin of which is difficult to determine.

What are the advantages of Redis?

One key advantage of NoSQL databases lies in their high performance and flexible application. Especially in the development of autonomous and self-learning IT structures, they offer the ability to optimally distribute resources. The features of Redis include some characteristics that are almost indispensable in today's growing data processing:

• Distribution of load across different nodes and servers
• Fast, direct access with low latency to individual information
• Building structured yet flexible databases with autonomous networking
• Data abstraction through hash values for mapping
• Easy programming of complex tasks without data conversion
• Support for numerous programming languages such as Perl, Java, Python, JS, C, PHP, or Ruby
• Possibility to combine replication architecture with numerous clusters
• Licensing under Open Source
• Many open-source extensions available through versioning systems like Git

Due to its benefits, major internet services like Twitter rely on the high performance and flexibility of Redis. For hosting, in addition to dedicated servers and VPS hosting, numerous cloud servers such as Amazon Web Services and Microsoft Azure are also available.

What are the disadvantages of Redis databases?

Redis databases use a distributed structure, which is also found in modern IoT solutions and is based, among other things, on the publication and querying of events. However, this also means a certain limitation in terms of integrity security and control over compliance. Additionally, the NoSQL approach presents certain technical disadvantages:

• No data integrity monitoring
• Very high demands on memory
• Accessing data only possible through their key
• Limited support for complex data sets
• Temporary storage poses the risk of data loss in case of hardware failure
• So far, no support for clustering data across multiple Dedicated Servers or VPS hosting

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