An introduction to CouchDB

“Apache CouchDB has started. Time to relax.” This is how users of the CouchDB database management system are greeted each time they launch the program. For many system developers easy management of a database is a top priority. “Couch”is intended to be easy to operate and comprehend for database laypersons who have little to no interest in technology. A number of intuitive, graspable elements and user-friendly operations make for a very unique open-source software, one in which the approaches of document-oriented databases are connected with relational databases. What Apache CouchDB can achieve, how and where it is used, and what advantages “Couch” can offer companies, we’ll explore in the following sections.

Databases are a very important part of running a business and are frequently used by software developers. Customer data, product data, shipping, and payment data, and hundreds of other data sets form the “nervous system” of most companies. But the way the data is stored fundamentally depends on the database model that is used. The traditional model for relational databases sorts datasets, for example, according to mutual relations. Non-relational models, which are also referred to as NoSQL databases, use other methods. One form of a non-relational database is, for example, the document-oriented database, such as the Apache CouchDB solution.

CouchDB is a databank management system that takes advantage of the best aspects of document-oriented databases in order to achieve the performance of relational databases. Responsible for Couch’s development is the Apache Software Foundation, which began working on the free software Apache CouchDB in 2005 and has since consistently continued to develop it.

CouchDB is compatible with the well-established operating systems Linux, Unix, macOS, and Windows and was developed in the Erlang programming language. The standard script language for access to Couch data sets is JavaScript.

Document-based databases such as CouchDB store data sets not in the form of tables and lines, but rather as independent, self-contained documents. This could be compared to invoices, for example.

An invoice is a standalone document that combines all relevant information into a complete data set – biller, invoice number, recipient, price, items sold, biller, and recipient address are essential information for this distinctive dataset. In a relational database, this information is divided across many different lines, which allows CouchDB to gather all this information in a single document. The data must, therefore, not be structured beforehand. The structure is the result of the document itself. That’s why CouchDB can be understood as a schema-free databank management system.

The document-oriented approach simplifies the development process considerably. Furthermore, it enables those data sets to be collected as bundles that, though they are semantically similar (for example, have the same file format), differentiate themselves in terms of syntax (with respect to composition and internal structure).

An advantage of CouchDB is the quality of synchronization of several databases, as efficient synchronization is important for distributing data in a CouchDB cluster. In this way, the resulting data redundancies relieve the entire system. Consequently, database requests can be responded to by different CouchDB authorities. Geographically distributed, giant database networks are easily achievable.

When synchronizing the database for different users at different locations, Apache CouchDB relies on an incremental strategy which has the crucial benefit of preventing poor or discontinued network connections from negatively affecting the synchronization process. If there are connection problems, the database solution continues where it left off before the connection was disrupted. With respect to these instances, the developers have emphasized that the system doesn’t ignore these types of eventualities and assumed that such errors can happen in everyday life.

Furthermore, CouchDB uses the beginner-friendly JSON format (short for Javascript Object Notation) for the transfer and storage of its data sets. This format owes its existence to its schema-free structure, which – unlike with relational models – allows for unstructured information to be stored.

Users can also count on the simple operation of CouchDB, as it relies on current and well-known web technologies such as REST, JSON, and JavaScript. There is nothing to prevent diverse usage that ranges from large server clusters to mobile end devices.

The developers themselves emphasize that they do not want to and are not able to supplant relational databases. Instead, they would like to position CouchDB alongside these and offer users a simple alternative. A document-oriented database is not recommendable or sufficient for every company.

For example, one must be clear about whether relational database systems are more practical and user-friendly for those who want to regularly edit their data sets in the form of invoices or other more complex requests. The reason for this is that they themselves would have to install the appropriate features in CouchDB, which would involve high costs and would require the appropriate expertise.

As we’ve already indicated, CouchDB is a good alternative in the web application development sector with many easy-to-operate features. In this regard, the developers emphasize that other database systems are often adapted for the web, while CouchDB was specifically made for it. For example, the database solution is used with many websites and Facebook applications. Furthermore, it was used in the past by Ubuntu – probably the most popular Linux distribution – in order to synchronize bookmarks and addresses – another example of so-called “real-world data.”

CouchDB is compatible with all major operating systems and can be downloaded from the developers’ website. The procedure during installation varies according to the system – under Linux/Ubuntu, the necessary steps look like the following:

First, update your Ubuntu installation’s package management and add the PPA repository:

Next, update the package management again:

Then install CouchDB with the following terminal command:

After a successful installation, start Apache CouchDB and open Futon – CouchDB’s web interface. Now, you can begin to create and maintain your data sets.