Glossary / Query Plan

Query Plan

Practical PostgreSQL glossary entry with a clear definition, example, and benchmarking context.

What Is Query Plan?

A query plan outlines how PostgreSQL will execute a SQL statement, including which indexes and join types to use. It’s generated by the optimizer and crucial for performance analysis.

Why It Matters for PostgreSQL Performance

In PostgreSQL performance work, Query Plan affects throughput, latency, or operational reliability depending on workload and configuration.

Practical Benchmarking Context

When benchmarking with pgbench, track how Query Plan changes behavior across scale factor, client concurrency, and storage conditions.

Use this term together with workload shape, concurrency level, and scale factor when interpreting pgbench outputs. Isolated values can be misleading without full run context.

Example

Tool: EXPLAIN shows the query plan tree.

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