Restore repeatable read for NewDatabaseSnapshot

syncapi/storage/shared/syncserver.go

@@ -56,25 +56,22 @@ type Database struct {
 }
 
 func (d *Database) NewDatabaseSnapshot(ctx context.Context) (*DatabaseTransaction, error) {
-	return d.NewDatabaseTransaction(ctx) // TODO: revert
+	txn, err := d.DB.BeginTx(ctx, &sql.TxOptions{
-	/*
+		// Set the isolation level so that we see a snapshot of the database.
-		txn, err := d.DB.BeginTx(ctx, &sql.TxOptions{
+		// In PostgreSQL repeatable read transactions will see a snapshot taken
-			// Set the isolation level so that we see a snapshot of the database.
+		// at the first query, and since the transaction is read-only it can't
-			// In PostgreSQL repeatable read transactions will see a snapshot taken
+		// run into any serialisation errors.
-			// at the first query, and since the transaction is read-only it can't
+		// https://www.postgresql.org/docs/9.5/static/transaction-iso.html#XACT-REPEATABLE-READ
-			// run into any serialisation errors.
+		Isolation: sql.LevelRepeatableRead,
-			// https://www.postgresql.org/docs/9.5/static/transaction-iso.html#XACT-REPEATABLE-READ
+		ReadOnly:  true,
-			Isolation: sql.LevelRepeatableRead,
+	})
-			ReadOnly:  true,
+	if err != nil {
-		})
+		return nil, err
-		if err != nil {
+	}
-			return nil, err
+	return &DatabaseTransaction{
-		}
+		Database: d,
-		return &DatabaseTransaction{
+		txn:      txn,
-			Database: d,
+	}, nil
-			txn:      txn,
-		}, nil
-	*/
 }
 
 func (d *Database) NewDatabaseTransaction(ctx context.Context) (*DatabaseTransaction, error) {