Introduction

YQL is an SQL-based language of universal declarative queries against data storage and processing systems, as well as an infrastructure to run such queries.

YQL benefits include:

  • a powerful graph execution engine that can build MapReduce pipelines with hundreds of nodes and adapt during computation;
  • ability to build complex data processing pipelines using SQL by storing subqueries in variables as chains of dependent queries and transactions;
  • predictable parallel execution of queries of any complexity;
  • efficient implementation of joins, subqueries, and window functions with no restrictions on their topology or nesting;
  • extensive function library;
  • support for custom functions in C++, Python, and JavaScript;
  • automatic execution of small parts of queries on prepared compute instances, bypassing MapReduce operations to reduce latency.

How to try

YQL provides a functional web interface in which, among other things, you can:

  • write query code;
  • start and stop execution of requests;
  • view the result of query execution;
  • view the query history.