Glossary / Dead Tuple

Dead Tuple

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

What Is Dead Tuple?

Dead tuples are outdated row versions left after DELETEs or UPDATEs. Autovacuum removes them to free space and maintain performance.

Why It Matters for PostgreSQL Performance

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

Practical Benchmarking Context

When benchmarking with pgbench, track how Dead Tuple 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: VACUUM or pg_stat_user_tables to track dead rows.

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