Metrics Reference Guide
Workflow Overview
View metrics via pg_stat_insights or specialised views such as pg_stat_insights_plan, pg_stat_insights_io, and pg_stat_insights_waits. Combine identifiers with execution/caching metrics for a holistic profile of each statement.
Sample metric projection
SELECT queryid,
calls,
total_exec_time,
shared_blks_hit,
shared_blks_read,
wal_bytes,
parallel_workers_launched,
jit_generation_time
FROM pg_stat_insights
ORDER BY total_exec_time DESC
LIMIT 20;Identity & Classification
userid, dbid, queryid
Identifiers for role, database, and fingerprint. Join with pg_roles and pg_database for human-readable names.
query
Normalized text of the statement. Use alongside queryid to fetch the canonical SQL.
calls, rows
Execution count and rows returned. Combine to compute throughput and efficiency.
Execution & Timing
total_exec_time, mean_exec_time, min/max/stddev_exec_time
Aggregate, average, and variability of execution time. Use stddev to detect jitter.
total_plan_time, mean_plan_time
Time spent planning statements (requires track_planning).
blk_read_time, blk_write_time
Block-level read/write timings (requires track_io_timing).
Cache, IO & WAL
shared_blks_hit / read / dirtied / written
Shared buffer interaction. Combine to compute cache hit ratio and flush pressure.
temp_blks_read / written
Temporary file usage signalling sorts or hash spills.
wal_bytes, wal_fpi_bytes, wal_records
WAL generation cost. Useful for analysing write amplification.
Advanced (Parallel & JIT)
parallel_workers_planned / launched / rejected
Parallel executor information for speedup analysis.
jit_functions, jit_generation_time, jit_emission_time…
LLVM compilation metrics indicating JIT overhead (track_planning required).
plans_since_last_reset, plans_with_leader_participation
Planner statistics for monitoring resets and leader activity.
Reset & Retention
Metrics accumulate until reset. Schedule resets post-maintenance or collect deltas into historical tables for trend analysis.
Reset command
SELECT pg_stat_insights_reset();Resets also clear derived views such as pg_stat_insights_plan. Capture baselines prior to reset if you rely on historical comparisons.