10.6. Query Performance Analysis

Presto provides several commands and utilities to help with performance analysis of your queries:

• The standard EXPLAIN command displays both logical and distributed query plans.
• The EXPLAIN ANALYZE command provides detailed execution-time metrics such as a number of input and output rows at each stage and aggregated CPU time.
• The Web Interface offers both a cluster-wide overview of all queries as well as a detailed view for each query. It includes the overall query metrics, stage-level progress and the task-level details. The Live Plan view displays the graphical representation of a distributed query plan with the execution metrics updated while a query is running.

The collected information can help with identifying the slow parts of a query and the means to address the performance challenges (for example, manually reordering joins).