Use ReadOnly transaction when managing replication slots.

postgresql/helpers.go

@@ -1,6 +1,7 @@
 package postgresql
 
 import (
+	"context"
 	"database/sql"
 	"fmt"
 	"log"
@@ -368,10 +369,10 @@ func setToPgIdentSimpleList(idents *schema.Set) string {
 	return strings.Join(quotedIdents, ",")
 }
 
-// startTransaction starts a new DB transaction on the specified database.
+// startTransactionWithOpts starts a new DB transaction on the specified database.
 // If the database is specified and different from the one configured in the provider,
-// it will create a new connection pool if needed.
-func startTransaction(client *Client, database string) (*sql.Tx, error) {
+// it will create a new connection pool if needed
+func startTransactionWithOpts(client *Client, database string, opts *sql.TxOptions) (*sql.Tx, error) {
 	if database != "" && database != client.databaseName {
 		client = client.config.NewClient(database)
 	}
@@ -380,14 +381,22 @@ func startTransaction(client *Client, database string) (*sql.Tx, error) {
 		return nil, err
 	}
 
-	txn, err := db.Begin()
+	txn, err := db.BeginTx(context.Background(), opts)
 	if err != nil {
 		return nil, fmt.Errorf("could not start transaction: %w", err)
 	}
 
 	return txn, nil
 }
 
+func startTransaction(client *Client, database string) (*sql.Tx, error) {
+	return startTransactionWithOpts(client, database, nil)
+}
+
+func startReadOnlyTransaction(client *Client, database string) (*sql.Tx, error) {
+	return startTransactionWithOpts(client, database, &sql.TxOptions{ReadOnly: true})
+}
+
 func dbExists(db QueryAble, dbname string) (bool, error) {
 	err := db.QueryRow("SELECT datname FROM pg_database WHERE datname=$1", dbname).Scan(&dbname)
 	switch {

postgresql/resource_postgresql_replication_slot.go

@@ -48,7 +48,7 @@ func resourcePostgreSQLReplicationSlotCreate(db *DBConnection, d *schema.Resourc
 	plugin := d.Get("plugin").(string)
 	databaseName := getDatabaseForReplicationSlot(d, db.client.databaseName)
 
-	txn, err := startTransaction(db.client, databaseName)
+	txn, err := startReadOnlyTransaction(db.client, databaseName)
 	if err != nil {
 		return err
 	}
@@ -83,7 +83,7 @@ func resourcePostgreSQLReplicationSlotExists(db *DBConnection, d *schema.Resourc
 		return false, err
 	}
 
-	txn, err := startTransaction(db.client, database)
+	txn, err := startReadOnlyTransaction(db.client, database)
 	if err != nil {
 		return false, err
 	}
@@ -111,7 +111,7 @@ func resourcePostgreSQLReplicationSlotReadImpl(db *DBConnection, d *schema.Resou
 		return err
 	}
 
-	txn, err := startTransaction(db.client, database)
+	txn, err := startReadOnlyTransaction(db.client, database)
 	if err != nil {
 		return err
 	}
@@ -144,7 +144,7 @@ func resourcePostgreSQLReplicationSlotDelete(db *DBConnection, d *schema.Resourc
 	replicationSlotName := d.Get("name").(string)
 	database := getDatabaseForReplicationSlot(d, db.client.databaseName)
 
-	txn, err := startTransaction(db.client, database)
+	txn, err := startReadOnlyTransaction(db.client, database)
 	if err != nil {
 		return err
 	}