createsequence

pkg/workload/schemachange/operation_generator.go

@@ -364,7 +364,6 @@ func (og *operationGenerator) createSequence(tx *pgx.Tx) (string, error) {
 		return "", err
 	}
 
-	ifNotExists := og.randIntn(2) == 0
 	schemaExists, err := schemaExists(tx, seqName.Schema())
 	if err != nil {
 		return "", err
@@ -374,6 +373,14 @@ func (og *operationGenerator) createSequence(tx *pgx.Tx) (string, error) {
 		return "", err
 	}
 
+	// If the sequence exists and an error should be produced, then
+	// exclude the IF NOT EXISTS clause from the statement. Otherwise, default
+	// to including the clause prevent all pgcode.DuplicateRelation errors.
+	ifNotExists := true
+	if sequenceExists && og.produceError() {
+		ifNotExists = false
+	}
+
 	codesWithConditions{
 		{code: pgcode.UndefinedSchema, condition: !schemaExists},
 		{code: pgcode.DuplicateRelation, condition: sequenceExists && !ifNotExists},