1. Structured Query Language (SQL) :
SQL is a domain-specific language used in programming and designed for managing data held in a relational database management system also known as RDBMS. It is also useful in handling structured data, i.e., data incorporating relations among entities and variables. SQL is a standard language for storing, manipulating and retrieving data in databases.
2. Hive Query Language (HiveQL) :
HiveQL is a query language for Hive to analyze and process structured data in a Meta-store. It is very much similar to SQL and highly scalable. It reuses familiar concepts from the relational database world, such as tables, rows, columns and schema, to ease learning. Hive supports four file formats those are TEXT FILE, SEQUENCE FILE, ORC and RC FILE (Record Columnar File).
Difference between SQL and HiveQL :
| On the basis of | SQL | HiveQL |
|---|---|---|
| Update-commands in table structure | UPDATE, DELETE INSERT, | UPDATE, DELETE INSERT, |
| Manages | Relational data | Data Structures |
| Transaction | Supported | Limited Support Supported |
| Indexes | Supported | Supported |
| Data Types | It contain a total of five data types i.e., Integral, floating-point, fixed-point, text and binary strings, temporal | It contains a total of 9 data types i.e., Boolean, integral, floating-point, fixed-point, text and binary strings, temporal, array, map, struct. |
| Functions | Hundreds of built-in functions | Hundreds of built-in functions |
| Mapreduce | Not Supported | Supported |
| Multitable inserts in table | Not supported | Supported |
| Create tabl…as Select | Not supported | Supported |
| Select command | Supported | Supported with SORT BY clause for partial ordering and LIMIT to restrict number of rows returned |
| Joins | Supported | Inner joins, outer joins, semi join, map joins, cross joins |
| Subqueries | Supported | Only Used in FROM, WHERE, or HAVING clauses |
| Views | Can be Updated | Read-only i.e. cannot be updated |
