From e58badfbe7e2e0beb62d6b01dcf38e1658815256 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 23 Dec 2000 19:55:16 +0000
Subject: [PATCH] Improve comments.
---
src/include/utils/rel.h | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index fd4012b0ddf..adde4a28e31 100644
--- 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))
--
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