Merge pull request #71 from luizm/feat/add-slow-queries-suport-pg-13

feat: add support pg13

Author: brunomanzo

gauges/slow_queries.go

@@ -1,20 +1,15 @@
 package gauges
 
 import (
+	"fmt"
 	"strings"
 	"time"
 
+	"github.com/ContaAzul/postgresql_exporter/postgres"
 	"github.com/apex/log"
 	"github.com/prometheus/client_golang/prometheus"
 )
 
-const slowQueriesQuery = `
-	SELECT total_time, query
-	FROM pg_stat_statements
-	WHERE dbid = (SELECT datid FROM pg_stat_database WHERE datname = current_database())
-	ORDER BY total_time desc limit 10
-`
-
 type slowQuery struct {
 	Query string  `db:"query"`
 	Time  float64 `db:"total_time"`
@@ -42,7 +37,17 @@ func (g *Gauges) SlowestQueries() *prometheus.GaugeVec {
 	go func() {
 		for {
 			var queries []slowQuery
-			if err := g.query(slowQueriesQuery, &queries, emptyParams); err == nil {
+			if err := g.query(
+				fmt.Sprintf(`
+					SELECT %[1]s as total_time, query
+					FROM pg_stat_statements
+					WHERE dbid = (SELECT datid FROM pg_stat_database WHERE datname = current_database())
+					ORDER BY %[1]s desc limit 10`,
+					postgres.Version(g.version()).PgStatStatementsTotalTimeColumn(),
+				),
+				&queries,
+				emptyParams,
+			); err == nil {
 				for _, query := range queries {
 					gauge.With(prometheus.Labels{
 						"query": strings.Join(strings.Fields(query.Query), " "),

postgres/version.go

@@ -13,6 +13,11 @@ func (v Version) IsEqualOrGreaterThan10() bool {
 	return v >= 100000
 }
 
+// IsEqualOrGreaterThan13 returns whether this version is greater than 13.0
+func (v Version) IsEqualOrGreaterThan13() bool {
+	return v >= 130000
+}
+
 // IsWalReplayPausedFunctionName returns the name of the function to verify whether the replication
 // log is paused according to the postgres version
 func (v Version) IsWalReplayPausedFunctionName() string {
@@ -49,11 +54,19 @@ func (v Version) LastWalReplayedLsnFunctionName() string {
 	return "pg_last_xlog_replay_location"
 }
 
-// CurrentWalLsnFunctionName returns the name of the function that gets current 
+// CurrentWalLsnFunctionName returns the name of the function that gets current
 // write-ahead log write location according to the postgres version
 func (v Version) CurrentWalLsnFunctionName() string {
 	if v.IsEqualOrGreaterThan10() {
 		return "pg_current_wal_lsn"
 	}
 	return "pg_current_xlog_location"
 }
+
+// PgStatStatementsTotalTimeColumn returns the name of the column that contains the total time spent executing the statement.
+func (v Version) PgStatStatementsTotalTimeColumn() string {
+	if v.IsEqualOrGreaterThan13() {
+		return "total_exec_time"
+	}
+	return "total_time"
+}

postgres/version_test.go

@@ -50,3 +50,26 @@ func TestIsEqualOrGreaterThan10(t *testing.T) {
 		})
 	}
 }
+
+func TestIsEqualOrGreaterThan13(t *testing.T) {
+	tt := []struct {
+		version  int
+		expected bool
+	}{
+		{90407, false},
+		{90600, false},
+		{90606, false},
+		{100000, false},
+		{100004, false},
+		{110000, false},
+		{110004, false},
+		{130000, true},
+	}
+
+	for _, tc := range tt {
+		testName := fmt.Sprintf("expecting IsEqualOrGreaterThan13(\"%v\") to be %v", tc.version, tc.expected)
+		t.Run(testName, func(t *testing.T) {
+			assert.Equal(t, Version(tc.version).IsEqualOrGreaterThan13(), tc.expected)
+		})
+	}
+}