Type: enum
Default: auto
Context: superuser
Restart: false
Values: [auto, regress, on, off]
Since: 14

Enables in-core computation of a query identifier. Query identifiers can be displayed in the pg_stat_activity view, using EXPLAIN, or emitted in the log if configured via the log_line_prefix parameter. The pgstatstatements extension also requires a query identifier to be computed. Note that an external module can alternatively be used if the in-core query identifier computation method is not acceptable. In this case, in-core computation must be always disabled. Valid values are off (always disabled), on (always enabled), auto, which lets modules such as pgstatstatements automatically enable it, and regress which has the same effect as auto, except that the query identifier is not shown in the EXPLAIN output in order to facilitate automated regression testing. The default is auto.

To ensure that only one query identifier is calculated and displayed, extensions that calculate query identifiers should throw an error if a query identifier has already been computed.