diff --git a/server/model/pipeline.go b/server/model/pipeline.go
index 77b39ab49..991839c69 100644
--- a/server/model/pipeline.go
+++ b/server/model/pipeline.go
@@ -24,7 +24,7 @@ type Pipeline struct {
 	Parent              int64             `json:"parent"                  xorm:"pipeline_parent"`
 	Event               WebhookEvent      `json:"event"                   xorm:"pipeline_event"`
 	Status              StatusValue       `json:"status"                  xorm:"INDEX 'pipeline_status'"`
-	Error               string            `json:"error"                   xorm:"pipeline_error"`
+	Error               string            `json:"error"                   xorm:"LONGTEXT 'pipeline_error'"`
 	Enqueued            int64             `json:"enqueued_at"             xorm:"pipeline_enqueued"`
 	Created             int64             `json:"created_at"              xorm:"pipeline_created"`
 	Updated             int64             `json:"updated_at"              xorm:"updated NOT NULL DEFAULT 0 'updated'"`
@@ -46,7 +46,7 @@ type Pipeline struct {
 	Reviewer            string            `json:"reviewed_by"             xorm:"pipeline_reviewer"`
 	Reviewed            int64             `json:"reviewed_at"             xorm:"pipeline_reviewed"`
 	Workflows           []*Workflow       `json:"workflows,omitempty"     xorm:"-"`
-	ChangedFiles        []string          `json:"changed_files,omitempty" xorm:"json 'changed_files'"`
+	ChangedFiles        []string          `json:"changed_files,omitempty" xorm:"LONGTEXT 'changed_files'"`
 	AdditionalVariables map[string]string `json:"variables,omitempty"     xorm:"json 'additional_variables'"`
 	PullRequestLabels   []string          `json:"pr_labels,omitempty"     xorm:"json 'pr_labels'"`
 } //	@name Pipeline
diff --git a/server/model/step.go b/server/model/step.go
index 2922f3f11..bf0661c9e 100644
--- a/server/model/step.go
+++ b/server/model/step.go
@@ -36,13 +36,13 @@ const (
 // Step represents a process in the pipeline.
 type Step struct {
 	ID         int64       `json:"id"                   xorm:"pk autoincr 'step_id'"`
-	UUID       string      `json:"uuid"                 xorm:"UNIQUE INDEX 'step_uuid'"`
+	UUID       string      `json:"uuid"                 xorm:"INDEX 'step_uuid'"`
 	PipelineID int64       `json:"pipeline_id"          xorm:"UNIQUE(s) INDEX 'step_pipeline_id'"`
 	PID        int         `json:"pid"                  xorm:"UNIQUE(s) 'step_pid'"`
 	PPID       int         `json:"ppid"                 xorm:"step_ppid"`
 	Name       string      `json:"name"                 xorm:"step_name"`
 	State      StatusValue `json:"state"                xorm:"step_state"`
-	Error      string      `json:"error,omitempty"      xorm:"VARCHAR(500) step_error"`
+	Error      string      `json:"error,omitempty"      xorm:"TEXT 'step_error'"`
 	Failure    string      `json:"-"                    xorm:"step_failure"`
 	ExitCode   int         `json:"exit_code"            xorm:"step_exit_code"`
 	Started    int64       `json:"start_time,omitempty" xorm:"step_started"`
diff --git a/server/model/workflow.go b/server/model/workflow.go
index b594631bd..edd5b0a45 100644
--- a/server/model/workflow.go
+++ b/server/model/workflow.go
@@ -22,7 +22,7 @@ type Workflow struct {
 	PID        int               `json:"pid"                  xorm:"UNIQUE(s) 'workflow_pid'"`
 	Name       string            `json:"name"                 xorm:"workflow_name"`
 	State      StatusValue       `json:"state"                xorm:"workflow_state"`
-	Error      string            `json:"error,omitempty"      xorm:"VARCHAR(500) workflow_error"`
+	Error      string            `json:"error,omitempty"      xorm:"TEXT 'workflow_error'"`
 	Started    int64             `json:"start_time,omitempty" xorm:"workflow_started"`
 	Stopped    int64             `json:"end_time,omitempty"   xorm:"workflow_stopped"`
 	AgentID    int64             `json:"agent_id,omitempty"   xorm:"workflow_agent_id"`
diff --git a/server/store/datastore/migration/020_parent_steps_to_workflows.go b/server/store/datastore/migration/020_parent_steps_to_workflows.go
index aa4e77cd9..18c21cbb8 100644
--- a/server/store/datastore/migration/020_parent_steps_to_workflows.go
+++ b/server/store/datastore/migration/020_parent_steps_to_workflows.go
@@ -27,7 +27,7 @@ type oldStep020 struct {
 	PPID       int               `xorm:"step_ppid"`
 	Name       string            `xorm:"step_name"`
 	State      model.StatusValue `xorm:"step_state"`
-	Error      string            `xorm:"VARCHAR(500) step_error"`
+	Error      string            `xorm:"TEXT 'step_error'"`
 	Started    int64             `xorm:"step_started"`
 	Stopped    int64             `xorm:"step_stopped"`
 	AgentID    int64             `xorm:"step_agent_id"`
diff --git a/server/store/datastore/step_test.go b/server/store/datastore/step_test.go
index 8238baa07..3fd385969 100644
--- a/server/store/datastore/step_test.go
+++ b/server/store/datastore/step_test.go
@@ -179,6 +179,8 @@ func TestStepIndexes(t *testing.T) {
 	defer closer()
 
 	sess := store.engine.NewSession()
+	defer sess.Close()
+
 	if err := store.stepCreate(sess, []*model.Step{
 		{
 			UUID:       "4db7e5fc-5312-4d02-9e14-b51b9e3242cc",
@@ -206,21 +208,6 @@ func TestStepIndexes(t *testing.T) {
 	}); err == nil {
 		t.Errorf("Unexpected error: duplicate pid")
 	}
-
-	// fail due to duplicate uuid
-	if err := store.stepCreate(sess, []*model.Step{
-		{
-			UUID:       "4db7e5fc-5312-4d02-9e14-b51b9e3242cc",
-			PipelineID: 5,
-			PID:        4,
-			PPID:       3,
-			State:      "success",
-			Name:       "clone",
-		},
-	}); err == nil {
-		t.Errorf("Unexpected error: duplicate pid")
-	}
-	_ = sess.Close()
 }
 
 func TestStepByUUID(t *testing.T) {