Issue #3229479: Entity_lookup taxonomy_term restricted by VID

src/Plugin/migrate_plus/data_parser/SimpleXml.php

@@ -10,6 +10,11 @@ use Drupal\migrate_plus\DataParserPluginBase;
 /**
  * Obtain XML data for migration using the SimpleXML API.
  *
+ * SimpleXML parses the whole file into memory, which allows using XPath
+ * expression in the item selector. For large XML sources it results in
+ * consuming lots of memory, which can be undesirable. If you run into memory
+ * issues, then consider using the 'xml' data parser.
+ *
  * @DataParser(
  *   id = "simple_xml",
  *   title = @Translation("Simple XML")