Metrics reference

Reference documentation for all metrics collected by PostgresAI monitoring.

Metric sources

PostgresAI monitoring collects metrics from multiple PostgreSQL sources:

Source	Description	Dashboard usage
pg_stat_statements	Query-level performance metrics	02, 03
pg_stat_activity	Session and wait event data	01, 04
pg_stat_user_tables	Table-level statistics	07, 08, 09
pg_stat_user_indexes	Index usage statistics	10, 11
pg_stat_replication	Replication metrics	06
pg_stat_bgwriter	Background writer stats	01
pg_stat_database	Database-level aggregates	01

Metric naming convention

All metrics follow the pattern:

pg_{source}_{metric_name}

Examples:

• pg_stat_statements_calls_total — Total query calls
• pg_stat_activity_count — Active session count
• pg_stat_user_tables_seq_scan_total — Sequential scans

Collection intervals

Metric type	Default interval	Configurable
Session metrics	10s	Yes
Query metrics	60s	Yes
Table/index metrics	60s	Yes
Replication metrics	10s	Yes

Metric categories

pg_stat_statements metrics

Query performance metrics including:

• Execution counts and timing
• Row counts
• Buffer usage
• Planning time

Wait event metrics

Active session history data:

• Wait event types and categories
• Session state distribution
• Lock wait analysis

Table metrics

Table-level statistics:

• Sequential vs index scans
• Dead tuple counts
• HOT update ratios
• Table sizes

Index metrics

Index usage and health:

• Scan counts
• Tuple reads
• Index sizes
• Bloat estimates

System metrics

PostgreSQL system-level metrics:

• Connection counts
• Transaction rates
• Checkpoint activity
• Buffer cache statistics

Prometheus/VictoriaMetrics queries

All metrics are stored in VictoriaMetrics (Prometheus-compatible). Example queries:

Rate calculations

# Queries per second
rate(pg_stat_statements_calls_total[5m])

# Transactions per second
rate(pg_stat_database_xact_commit_total[5m])

Aggregations

# Total active sessions across all databases
sum(pg_stat_activity_count{state="active"})

# Average query time by database
avg by (datname) (pg_stat_statements_mean_exec_time_seconds)

Related documentation

• Dashboard overview — How metrics are visualized
• Getting started — Installation and setup