Explain Plan (Single-Stage)

How to inspect Pinot's execution plan for a query.

Use EXPLAIN PLAN FOR when you want to understand how Pinot will execute a query before or while tuning it.

What it tells you

Explain plan output helps you see:

• which operators Pinot will run

• whether an index is being used

• where filters, projections, and aggregations happen

• how a query is shaped in single-stage or multi-stage execution

EXPLAIN PLAN FOR
SELECT city, COUNT(*)
FROM stores
GROUP BY city;

Single-stage and multi-stage

Single-stage explain plans are best for understanding the operator flow behind straightforward queries.

Multi-stage explain plans are better when you need to inspect joins, subqueries, or the distributed execution shape.

How to use it

Start with explain plan when a query is:

• slower than expected

• not using the index you expected

• returning a shape that is hard to reason about

Then pair the plan with query options or index guidance if you need a fix.

What this page covered

This page covered what explain plan shows, when to use it, and how the single-stage and multi-stage engines differ.

Next step

If you need a deeper execution-shape discussion, read SQL syntax and then revisit query options or quotas if the issue is runtime control rather than syntax.

Related pages

• Query options

• Querying Pinot

• SQL syntax