Unreasonable Effectiveness of SQL

In the years since Don Chamberlin and Ramond Boyce published SEQUEL: A Structured English Query Language relational model and SQL have been extended and adapted to a significant number of technologies: OLTP, OLAP, object databases, object-relational databases, and even NoSQL. SQL has inspired query language design for non-relational databases: SQL for object databases, SQL for object-relational, SQL for XML, SQL for spatial, SQL for search, SQL for JSON, SQL for timeseries, SQL for streams and so on. As Don said recently, SQL was based on the foundation of relational algebra with the goal to make it easier by providing an English like query language with the following goals:

While the big data tried to compliment and replace relational systems for data warehousing, they tried to speak the same language: SQL.

Source: blog.couchbase.com