From 735667b51cf74e6e12ca83374d5cf19f35c5bf40 Mon Sep 17 00:00:00 2001
From: randomdan <randomdan@localhost>
Date: Sun, 13 Feb 2011 01:43:50 +0000
Subject: Minor tweaks to improve perforamce on PG bulk deletes Fixes to
 support partial merges with bulk updates

---
 project2/tablepatch.cpp | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/project2/tablepatch.cpp b/project2/tablepatch.cpp
index 3533b65..aacedbb 100644
--- a/project2/tablepatch.cpp
+++ b/project2/tablepatch.cpp
@@ -254,7 +254,7 @@ TablePatch::doUpdates(const char * where, const char * order)
 				// Build SQL for list of updates to perform ------------------------
 				// -----------------------------------------------------------------
 				Buffer updSql;
-				updSql.appendf("UPDATE %s SET ",
+				updSql.appendf("UPDATE %s a SET ",
 						dest.c_str());
 				bool first = true;
 				foreach (Columns::const_iterator, cols, col) {
@@ -276,8 +276,8 @@ TablePatch::doUpdates(const char * where, const char * order)
 					else {
 						updSql.append(" AND ");
 					}
-					updSql.appendf(" %s.%s = b.%s ",
-							dest.c_str(), pki->c_str(), pki->c_str());
+					updSql.appendf(" a.%s = b.%s ",
+							pki->c_str(), pki->c_str());
 				}
 				updSql.append(" AND (");
 				first = true;
@@ -288,10 +288,10 @@ TablePatch::doUpdates(const char * where, const char * order)
 						}
 						first = false;
 						updSql.appendf(
-								" (((CASE WHEN (%s.%s IS NULL AND b.%s IS NULL) THEN 1 ELSE 0 END) \
-							+ (CASE WHEN(%s.%s = b.%s) THEN 1 ELSE 0 END)) = 0)",
-								dest.c_str(), col->c_str(), col->c_str(),
-								dest.c_str(), col->c_str(), col->c_str());
+								" (((CASE WHEN (a.%s IS NULL AND b.%s IS NULL) THEN 1 ELSE 0 END) \
+							+ (CASE WHEN(a.%s = b.%s) THEN 1 ELSE 0 END)) = 0)",
+								col->c_str(), col->c_str(),
+								col->c_str(), col->c_str());
 					}
 				}
 				updSql.append(")");
-- 
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