Update file header comments for logical/relation.c.
Author: Amit Langote
Discussion:
/*-------------------------------------------------------------------------
* relation.c
- * PostgreSQL logical replication
+ * PostgreSQL logical replication relation mapping cache
*
* Copyright (c) 2016-2020, PostgreSQL Global Development Group
*
* src/backend/replication/logical/relation.c
*
* NOTES
- * This file contains helper functions for logical replication relation
- * mapping cache.
+ * Routines in this file mainly have to do with mapping the properties
+ * of local replication target relations to the properties of their
+ * remote counterpart.
*
*-------------------------------------------------------------------------
*/
