O'Reilly logo

Getting Started with Greenplum for Big Data Analytics by Sunila Gollapudi

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

In-database analytics options (Greenplum-specific)

This section covers advanced SQL techniques for in-database analytics within Greenplum.

The following techniques will be discussed in detail:

  • Windows functions
  • User-defined functions and aggregates

Window functions

Window functions are a new class of functions introduced in Greenplum. The WINDOW clause is used to define a window that can be used in the OVER() expression of a window function such as rank or avg. For information on OLAP extensions and window functions refer to the Greenplum Database Reference guide. Window functions allow application developers to more easily compose complex OLAP queries using standard SQL commands. For example:

  • Moving averages or sums can be calculated over various intervals. ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required