From 148ec3b1d888f18cd5579c0e31dbc615a941a993 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Sat, 20 Feb 1999 16:32:35 +0000
Subject: [PATCH] update pathkey description.
---
src/backend/optimizer/path/pathkeys.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 29f11dcd1c4..e19eeec01ff 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.2 1999/02/20 16:28:20 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.3 1999/02/20 16:32:35 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@@ -38,7 +38,7 @@ static List *new_matching_subkeys(Var *subkey, List *considered_subkeys,
/*
* Explanation of Path.pathkeys
*
- * This structure is a List of List of Var nodes that represent the sort
+ * Path.pathkeys is a List of List of Var nodes that represent the sort
* order of the result generated by the Path.
*
* In single/base relation RelOptInfo's, the Path's represent various ways
@@ -49,8 +49,8 @@ static List *new_matching_subkeys(Var *subkey, List *considered_subkeys,
*
* Multi-relation RelOptInfo Path's are more complicated. Mergejoins are
* only performed with equajoins("="). Because of this, the multi-relation
- * path actually has more than one ordering. For example, a mergejoin Path
- * of "tab1.col1 = tab2.col1" would generate a pathkeys of
+ * path actually has more than one primary Var key. For example, a
+ * mergejoin Path of "tab1.col1 = tab2.col1" would generate a pathkeys of
* { {tab1.col1, tab2.col1} }. This allows future joins to use either Var
* as a pre-sorted key to prevent Mergejoins from having to re-sort the Path.
* They are equal, so they are both primary sort keys. This is why pathkeys
--
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