fixTest

metacat-common-server/src/main/java/com/netflix/metacat/common/server/usermetadata/ParentChildRelMetadataService.java

@@ -12,11 +12,14 @@
  */
 public interface ParentChildRelMetadataService {
     /**
-     * Create parent child relationship with its relation type.
+     * Establishes a parent-child relationship with a specified relation type.
+     * Currently, exceptions are thrown in the following cases:
+     * 1. Attempting to create a child table as the parent of another child table.
+     * 2. A child table having more than one parent.
      *
-     * @param parentName  parentName
-     * @param childName   childName
-     * @param relationType type of the relationship
+     * @param parentName    the name of the parent entity
+     * @param childName     the name of the child entity
+     * @param relationType  the type of the relationship
      */
     void createParentChildRelation(
         QualifiedName parentName,
@@ -25,20 +28,29 @@ void createParentChildRelation(
     );
 
     /**
-     * Rename oldName to newName in the parentChildRelationship store.
+     * Renames `oldName` to `newName` in the parentChildRelationship store.
+     * This involves two steps:
+     * 1. Rename all records where the child is `oldName` to `newName`.
+     * 2. Rename all records where the parent is `oldName` to `newName`.
+     * Since a child cannot be a parent of another entity, only one of these actions will need to be performed.
      *
-     * @param oldName  oldName
-     * @param newName  newName
+     * @param oldName  the current name to be renamed
+     * @param newName  the new name to rename to
      */
     void rename(
         QualifiedName oldName,
         QualifiedName newName
     );
 
     /**
-     * drop the entity from the parentChildRelationship store.
+     * Removes the entity from the parentChildRelationship store.
+     * An exception is thrown if an attempt is made to drop a parent table that still has existing child tables.
+     * Note that only dropping a child table will result in the physical deletion of records.
+     * When all children of a parent table are dropped, no records remain.
+     * Consequently, at then time when dropping the parent table, there should not have any database records
+     * with a parent reference to the dropping parent table.
      *
-     * @param name  name
+     * @param name  the name of the entity to drop
      */
     void drop(
         QualifiedName name