Key-value applications make use of associative arrays that assign each key a unique value in a given collection. The relationship between the two is known as key-value pair. The key can be a URI, a filename or a hash. The value can be any type of data such as images, user documents or various other files. There are several good advantages to writing key-value applications, as you’ll in this article, below.
The first advantage of these applications is that they are very fast in comparison with relational databases. This speed is in fact a result of their simplicity. Since the key-value database stores a data record by using solely a primary key, you can directly access this data record. The fact that these applications don’t rely on serializing data to pass it on to the client, and to deserialize it and decode it makes them extremely fast. Besides, this direct access requires less processing power. This means that you can obtain awesome results in terms of speed without having to upgrade your machines to integrate more powerful processors.
Another good advantage of writing key–value applications is that they are highly scalable. A NoSQL key-value database can scale over multiple machines or devices without the need for a major redesign. This opens a wide array of opportunities, hence the tremendous popularity of this type of application. Even in case you only need vertical scaling you’ll enjoy excellent stability. Sometimes, you may be able to manage huge databases, in the terabyte range, without any problems. This also leads to a very important financial advantage of this type of application. Using the same infrastructure can result in important savings for most companies, with important benefits for the end-consumers. Sometimes, such small details can make a huge difference.
The relatively small investment of time and effort is another good reason why these applications seem to have a brilliant future. More and more companies understand that the faster they can create a product, the cheaper they can sell it while also keeping a nice profitability rate. Since the time required to develop new applications is shorter and the working teams involve less individuals, the productivity of these companies increases. A high productivity has a direct influence on the price of the products.
Last but not least, the schema-free integration makes this solution one of the best in its class. The biggest problem of SQLite is that it only works properly for websites getting less than 100k hits a day. Above this value, most of these websites will start to encounter problems. There will be some, though, that will be just fine in the 200k hits per day range. However, embedded key-value stores are capable of much better performance.
These are a few of the main advantages of this type of application. At the same time, the drawback appears to be a lack in search, due to the fact that you’ll only be able to query for items by their keys. However, there are some reliable workarounds to this issue.