From bd209424aa2dbd1c936ec4527f2c8e5dfa16eb84 Mon Sep 17 00:00:00 2001
From: Lukas Eder <lukas.eder@gmail.com>
Date: Wed, 23 Oct 2013 17:37:00 +0200
Subject: [PATCH] [#2658] Inefficient emulation of row value expression
 comparison predicates <, <=, >, >=. Factor out predicates for improved index
 usage

---
 .../main/java/org/jooq/impl/RowCondition.java | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/jOOQ/src/main/java/org/jooq/impl/RowCondition.java b/jOOQ/src/main/java/org/jooq/impl/RowCondition.java
index 258ec7cd1f..a357e85711 100644
--- a/jOOQ/src/main/java/org/jooq/impl/RowCondition.java
+++ b/jOOQ/src/main/java/org/jooq/impl/RowCondition.java
@@ -149,6 +149,14 @@ class RowCondition extends AbstractCondition {
                 : (comparator == LESS_OR_EQUAL) ? LESS
                 : null;
 
+            // [#2658] The factored order component of the comparator (enforcing the equal component)
+            Comparator factoredOrder
+                = (comparator == GREATER) ? GREATER_OR_EQUAL
+                : (comparator == GREATER_OR_EQUAL) ? GREATER_OR_EQUAL
+                : (comparator == LESS) ? LESS_OR_EQUAL
+                : (comparator == LESS_OR_EQUAL) ? LESS_OR_EQUAL
+                : null;
+
             // Whether the comparator has an equal component
             boolean equal
                 = (comparator == GREATER_OR_EQUAL)
@@ -178,6 +186,17 @@ class RowCondition extends AbstractCondition {
             }
 
             Condition result = new CombinedCondition(Operator.OR, outer);
+
+            // [#2658] For performance reasons, an additional, redundant
+            // predicate is factored out to favour the application of range
+            // scans as the topmost predicate is AND-connected, not
+            // OR-connected:
+            // (A, B, C) > (X, Y, Z)
+            // (A >= X) AND ((A > X) OR (A = X AND B > Y) OR (A = X AND B = Y AND C > Z))
+            if (leftFields.length > 1) {
+                result = leftFields[0].compare(factoredOrder, (Field) rightFields[0]).and(result);
+            }
+
             return (QueryPartInternal) result;
         }
         else {