How do I index a database column

Question

Hopefully, I can get answers for each database server.

For an outline of how indexing works check out: How does database indexing work?

Answer 1

An index is not always needed for all the databases. For eg: Kognitio aka WX2 engine doesn't offer a syntax for indexing as the database engine takes care of it implicitly. Data goes on via round-robin partitioning and Kognitio WX2 gets data on and off disk in the simplest possible way.