SQL
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F. Boyce after learning about the relational model from Ted Codd in the early 1970s. This version, initially called "SEQUEL" ("Structured English Query Language"), was designed to manipulate and retrieve data stored in IBM's original quasi-relational database management system, System R, which a group at IBM San Jose Research Laboratory had developed during the 1970s.
Data analysis expressions
DAX was developed by the SQL Server Analysis Services team at Microsoft as part of Project Gemini and released in 2009 with the first version of the PowerPivot for Excel 2010 Add-in. Both DAX and MDX can be used to query PowerPivot and Tabular models, however only MDX may be used to query multidimensional SSAS models (cubes) in versions of SSAS up to SQL Server 2012 RTM. Future versions of SSAS (both multidimensional & tabular models) will support DAX natively.
2016 marks a significant improvement with the rapid adoption of Microsoft Power BI and SQL Server 2016. Power BI is a subscription-based self-service analytic tool and Power BI Desktop is a desktop analytic and report authoring application. SQL Server 2016 includes a new release of SQL Analysis Services Tabular with many improvements over previous versions. Enhancements to the DAX language in 2016 include support for calculated tables, automatic date table generation, variables and a total of 248 functions.