Metrics collection for PostgreSQL extensions. Provides counters, gauges, and histograms with JSONB labels, stored in dynamic shared memory. The metrics are stored in a dshash.

Load pmetrics before dependent extensions in shared_preload_libraries.

Dependent extensions should check pmetrics_is_initialized() in their shmem_startup hook.

Check pmetrics_stmts or the simpler pmetrics_txn for usage examples.

Functions

Counters: pmetrics_increment_counter(), pmetrics_increment_counter_by().

Gauges: pmetrics_set_gauge(), pmetrics_add_to_gauge().

Histograms: pmetrics_record_to_histogram().

Utilities: pmetrics_is_initialized(), pmetrics_is_enabled(), pmetrics_get_dsa(), pmetrics_clear_metrics(), pmetrics_delete_metric().