diff --git a/superset-frontend/spec/javascripts/datasource/DatasourceEditor_spec.jsx b/superset-frontend/spec/javascripts/datasource/DatasourceEditor_spec.jsx
index a6758fb2031..3caa82b160e 100644
--- a/superset-frontend/spec/javascripts/datasource/DatasourceEditor_spec.jsx
+++ b/superset-frontend/spec/javascripts/datasource/DatasourceEditor_spec.jsx
@@ -152,9 +152,7 @@ describe('DatasourceEditor', () => {
     beforeAll(() => {
       isFeatureEnabledMock = jest
         .spyOn(featureFlags, 'isFeatureEnabled')
-        .mockImplementation(
-          feature => feature === 'ENABLE_DATASET_SOURCE_EDIT',
-        );
+        .mockImplementation(() => false);
       wrapper = shallow(el, { context: { store } }).dive();
     });
 
diff --git a/superset-frontend/src/datasource/DatasourceEditor.jsx b/superset-frontend/src/datasource/DatasourceEditor.jsx
index a03d2ccc1e9..e6b21d5d339 100644
--- a/superset-frontend/src/datasource/DatasourceEditor.jsx
+++ b/superset-frontend/src/datasource/DatasourceEditor.jsx
@@ -715,8 +715,8 @@ class DatasourceEditor extends React.PureComponent {
                       <TextAreaControl
                         language="sql"
                         offerEditInModal={false}
-                        minLines={25}
-                        maxLines={25}
+                        minLines={20}
+                        maxLines={20}
                         readOnly={!this.state.isEditMode}
                       />
                     }
diff --git a/superset-frontend/src/explore/components/controls/TextAreaControl.jsx b/superset-frontend/src/explore/components/controls/TextAreaControl.jsx
index b1bb5d3ca7f..0bcf2d12860 100644
--- a/superset-frontend/src/explore/components/controls/TextAreaControl.jsx
+++ b/superset-frontend/src/explore/components/controls/TextAreaControl.jsx
@@ -78,10 +78,14 @@ export default class TextAreaControl extends React.Component {
     const value = this.props.value || '';
     const minLines = inModal ? 40 : this.props.minLines || 12;
     if (this.props.language) {
+      const style = { border: '1px solid #CCC' };
+      if (this.props.readOnly) {
+        style.backgroundColor = '#f2f2f2';
+      }
       return (
         <TextAreaEditor
           mode={this.props.language}
-          style={{ border: '1px solid #CCC' }}
+          style={style}
           minLines={minLines}
           maxLines={inModal ? 1000 : this.props.maxLines}
           onChange={this.onAceChangeDebounce}