CBO in Hive is powered by Apache Calcite (http://calcite.apache.org/), which is an open source, enterprise-grade cost-based logical optimizer and query execution framework. Hive CBO generates efficient execution plans by examining the query cost, which is collected by ANALYZE statements or the metastore itself, ultimately cutting down on query execution time and reducing resource utilization. To use CBO, set the following properties:

> SET hive.cbo.enable=true; -- default true after v0.14.0
> SET hive.compute.query.using.stats=true; -- default false
> SET hive.stats.fetch.column.stats=true; -- default false
> SET hive.stats.fetch.partition.stats=true; -- default true