server_version_num

Definition PG 18 manual

Reports the version number of the server as an integer. It is determined by the value of PG_VERSION_NUM when building the server.

How it works

Reports the running server binary’s version as an integer. It is internal/read-only and is determined by the binary, not by initdb or database creation.

For the measured PG9.0–19 Beta 3 releases, the integer encodes the major version and minor update so software can make numeric feature/version comparisons without parsing vendor text from server_version.

Use it for compatibility gating only when server-side feature discovery is unavailable. Extensions and clients must still account for vendor backports that do not change the upstream version number.

Operational considerations

Comparing the integer as a string.

Trying to change it with configuration or by recreating a database.

Assuming the number captures vendor backports and downstream patches.

Using a client-library version as a substitute for the connected server version.

Workload guidance

OLAP: Verify coordinator, workers, replicas, and extension builds against the actual server version before enabling version-specific SQL or planner features.

OLTP: Not tunable. Record it from every server after upgrade and use numeric comparisons in deployment checks; changing it means running a different PostgreSQL binary.

SMALL: Use the value for simple compatibility checks, but prefer probing the required feature. Do not attempt to alter it through configuration or initdb.