Improve comments.

diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index fd4012b0ddf1b5f8f73b80b605336a8d2b374504..adde4a28e31c99976311a674b581e4a2f7ba5c06 100644 (file)
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: rel.h,v 1.42 2000/11/08 22:10:02 tgl Exp $
+ * $Id: rel.h,v 1.43 2000/12/23 19:55:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -185,12 +185,16 @@ typedef Relation *RelationPtr;
 /*
  * RelationGetRelationName
  *
- *       Returns a Relation Name
+ *       Returns the relation's logical name (as seen by the user).
+ *
+ * If the rel is a temp rel, the temp name will be returned.  Therefore,
+ * this name is not unique.  But it is the name to use in heap_openr(),
+ * for example.
  */
 #define RelationGetRelationName(relation) \
 (\
        (strncmp(RelationGetPhysicalRelationName(relation), \
-        "pg_temp.", strlen("pg_temp.")) != 0) \
+                        "pg_temp.", 8) != 0) \
        ? \
                RelationGetPhysicalRelationName(relation) \
        : \
@@ -202,7 +206,15 @@ typedef Relation *RelationPtr;
 /*
  * RelationGetPhysicalRelationName
  *
- *       Returns a Relation Name
+ *       Returns the rel's physical name, ie, the name appearing in pg_class.
+ *
+ * While this name is unique across all rels in the database, it is not
+ * necessarily useful for accessing the rel, since a temp table of the
+ * same name might mask the rel.  It is useful mainly for determining if
+ * the rel is a shared system rel or not.
+ *
+ * The macro is rather unfortunately named, since the pg_class name no longer
+ * has anything to do with the file name used for physical storage of the rel.
  */
 #define RelationGetPhysicalRelationName(relation) \
        (NameStr((relation)->rd_rel->relname))