Add 'postgres_table_tuples_total' based on pg_class.reltuples.

internal/collector/postgres_tables.go

@@ -12,15 +12,16 @@ import (
 
 const (
 	userTablesQuery = "SELECT current_database() AS database, s1.schemaname AS schema, s1.relname AS table, " +
-		"seq_scan, seq_tup_read, idx_scan, idx_tup_fetch, n_tup_ins, n_tup_upd, n_tup_del, n_tup_hot_upd, n_live_tup, n_dead_tup, " +
-		"n_mod_since_analyze," +
-		"extract('epoch' from age(now(), greatest(last_vacuum, last_autovacuum))) as last_vacuum_seconds, " +
-		"extract('epoch' from age(now(), greatest(last_analyze, last_autoanalyze))) as last_analyze_seconds, " +
-		"extract('epoch' from greatest(last_vacuum, last_autovacuum)) as last_vacuum_time," +
-		"extract('epoch' from greatest(last_analyze, last_autoanalyze)) as last_analyze_time," +
+		"seq_scan, seq_tup_read, idx_scan, idx_tup_fetch, n_tup_ins, n_tup_upd, n_tup_del, n_tup_hot_upd, " +
+		"n_live_tup, n_dead_tup, n_mod_since_analyze, " +
+		"extract('epoch' from age(now(), greatest(last_vacuum, last_autovacuum))) AS last_vacuum_seconds, " +
+		"extract('epoch' from age(now(), greatest(last_analyze, last_autoanalyze))) AS last_analyze_seconds, " +
+		"extract('epoch' from greatest(last_vacuum, last_autovacuum)) AS last_vacuum_time," +
+		"extract('epoch' from greatest(last_analyze, last_autoanalyze)) AS last_analyze_time," +
 		"vacuum_count, autovacuum_count, analyze_count, autoanalyze_count, heap_blks_read, heap_blks_hit, idx_blks_read, " +
-		"idx_blks_hit, toast_blks_read, toast_blks_hit, tidx_blks_read, tidx_blks_hit, pg_table_size(s1.relid) AS size_bytes " +
-		"FROM pg_stat_user_tables s1 JOIN pg_statio_user_tables s2 USING (schemaname, relname) " +
+		"idx_blks_hit, toast_blks_read, toast_blks_hit, tidx_blks_read, tidx_blks_hit, " +
+		"pg_table_size(s1.relid) AS size_bytes, reltuples " +
+		"FROM pg_stat_user_tables s1 JOIN pg_statio_user_tables s2 USING (schemaname, relname) JOIN pg_class c ON s1.relid = c.oid " +
 		"WHERE NOT EXISTS (SELECT 1 FROM pg_locks WHERE relation = s1.relid AND mode = 'AccessExclusiveLock' AND granted)"
 )
 
@@ -44,6 +45,7 @@ type postgresTablesCollector struct {
 	maintenance          typedDesc
 	io                   typedDesc
 	sizes                typedDesc
+	reltuples            typedDesc
 	labelNames           []string
 }
 
@@ -164,6 +166,12 @@ func NewPostgresTablesCollector(constLabels labels, settings model.CollectorSett
 			labels, constLabels,
 			settings.Filters,
 		),
+		reltuples: newBuiltinTypedDesc(
+			descOpts{"postgres", "table", "tuples_total", "Number of rows in the table based on pg_class.reltuples value.", 0},
+			prometheus.GaugeValue,
+			labels, constLabels,
+			settings.Filters,
+		),
 	}, nil
 }
 
@@ -278,6 +286,7 @@ func (c *postgresTablesCollector) Update(config Config, ch chan<- prometheus.Met
 			}
 
 			ch <- c.sizes.newConstMetric(stat.sizebytes, stat.database, stat.schema, stat.table)
+			ch <- c.reltuples.newConstMetric(stat.reltuples, stat.database, stat.schema, stat.table)
 		}
 	}
 
@@ -317,6 +326,7 @@ type postgresTableStat struct {
 	tidxread        float64
 	tidxhit         float64
 	sizebytes       float64
+	reltuples       float64
 }
 
 // parsePostgresTableStats parses PGResult and returns structs with stats values.
@@ -422,6 +432,8 @@ func parsePostgresTableStats(r *model.PGResult, labelNames []string) map[string]
 				s.tidxhit = v
 			case "size_bytes":
 				s.sizebytes = v
+			case "reltuples":
+				s.reltuples = v
 			default:
 				continue
 			}

internal/collector/postgres_tables_test.go

@@ -28,6 +28,7 @@ func TestPostgresTablesCollector_Update(t *testing.T) {
 			"postgres_table_last_analyze_time",
 			"postgres_table_maintenance_total",
 			"postgres_table_size_bytes",
+			"postgres_table_tuples_total",
 		},
 		optional: []string{
 			"postgres_table_io_blocks_total",
@@ -49,7 +50,7 @@ func Test_parsePostgresTableStats(t *testing.T) {
 			name: "normal output",
 			res: &model.PGResult{
 				Nrows: 1,
-				Ncols: 30,
+				Ncols: 32,
 				Colnames: []pgproto3.FieldDescription{
 					{Name: []byte("database")}, {Name: []byte("schema")}, {Name: []byte("table")},
 					{Name: []byte("seq_scan")}, {Name: []byte("seq_tup_read")}, {Name: []byte("idx_scan")}, {Name: []byte("idx_tup_fetch")},
@@ -59,6 +60,7 @@ func Test_parsePostgresTableStats(t *testing.T) {
 					{Name: []byte("vacuum_count")}, {Name: []byte("autovacuum_count")}, {Name: []byte("analyze_count")}, {Name: []byte("autoanalyze_count")},
 					{Name: []byte("heap_blks_read")}, {Name: []byte("heap_blks_hit")}, {Name: []byte("idx_blks_read")}, {Name: []byte("idx_blks_hit")},
 					{Name: []byte("toast_blks_read")}, {Name: []byte("toast_blks_hit")}, {Name: []byte("tidx_blks_read")}, {Name: []byte("tidx_blks_hit")},
+					{Name: []byte("size_bytes")}, {Name: []byte("reltuples")},
 				},
 				Rows: [][]sql.NullString{
 					{
@@ -70,6 +72,7 @@ func Test_parsePostgresTableStats(t *testing.T) {
 						{String: "910", Valid: true}, {String: "920", Valid: true}, {String: "930", Valid: true}, {String: "940", Valid: true},
 						{String: "4528", Valid: true}, {String: "5845", Valid: true}, {String: "458", Valid: true}, {String: "698", Valid: true},
 						{String: "125", Valid: true}, {String: "825", Valid: true}, {String: "699", Valid: true}, {String: "375", Valid: true},
+						{String: "458523", Valid: true}, {String: "50000", Valid: true},
 					},
 				},
 			},
@@ -80,6 +83,7 @@ func Test_parsePostgresTableStats(t *testing.T) {
 					inserted: 300, updated: 400, deleted: 500, hotUpdated: 150, live: 600, dead: 100, modified: 500,
 					lastvacuumAge: 700, lastanalyzeAge: 800, lastvacuumTime: 12345678, lastanalyzeTime: 87654321, vacuum: 910, autovacuum: 920, analyze: 930, autoanalyze: 940,
 					heapread: 4528, heaphit: 5845, idxread: 458, idxhit: 698, toastread: 125, toasthit: 825, tidxread: 699, tidxhit: 375,
+					sizebytes: 458523, reltuples: 50000,
 				},
 			},
 		},