# Single-stage query engine (v1)

The Pinot single-stage query engine (also known as v1 query engine) uses a scatter-gather query engine model, shown in the following diagram. In certain cases, for example, if you need to query using JOINs on large data sets, the [multi-stage query engine (v2)](https://docs.pinot.apache.org/release-1.2.0/reference/multi-stage-engine) may be a more performant option.

<figure><img src="https://content.gitbook.com/content/OJJ0Nzm428Z8ZYkcArkz/blobs/P4mWTtdYarEuTx7FU4H0/Multi-Stage-Pinot-Query-Engine-v1.png" alt=""><figcaption><p>Single-stage query engine (v1)</p></figcaption></figure>