[calcite] branch master updated: [CALCITE-3192] Simplification may weaken OR conditions containing inequalities

[kgyrtkirk]

This is an automated email from the ASF dual-hosted git repository.

kgyrtkirk pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/calcite.git


The following commit(s) were added to refs/heads/master by this push:
     new f7762b6  [CALCITE-3192] Simplification may weaken OR conditions 
containing inequalities
f7762b6 is described below

commit f7762b6a7cd85711a8cc6d7c7174dedca22bdcd2
Author: Zoltan Haindrich <k...@rxd.hu>
AuthorDate: Mon Jul 29 17:51:53 2019 +0200

    [CALCITE-3192] Simplification may weaken OR conditions containing 
inequalities
    
    For expressions like: (1 < x or ( x < 3 and c ))
    simplification was made to ( 1 < x or c )
---
 .../java/org/apache/calcite/rex/RexSimplify.java   | 29 ++++++++++++++++++++--
 .../org/apache/calcite/test/RexProgramTest.java    | 12 +++++++++
 .../org/apache/calcite/test/RelOptRulesTest.xml    |  4 +--
 3 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/core/src/main/java/org/apache/calcite/rex/RexSimplify.java 
b/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
index 187b926..bbf6b28 100644
--- a/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
+++ b/core/src/main/java/org/apache/calcite/rex/RexSimplify.java
@@ -502,7 +502,7 @@ public class RexSimplify {
     RexSimplify simplify = this;
     for (int i = 0; i < terms.size(); i++) {
       final RexNode t = terms.get(i);
-      if (Predicate.of(t) == null) {
+      if (!allowedAsPredicateDuringOrSimplification(t)) {
         continue;
       }
       final RexNode t2 = simplify.simplify(t, unknownAs);
@@ -516,13 +516,38 @@ public class RexSimplify {
     }
     for (int i = 0; i < terms.size(); i++) {
       final RexNode t = terms.get(i);
-      if (Predicate.of(t) != null) {
+      if (allowedAsPredicateDuringOrSimplification(t)) {
         continue;
       }
       terms.set(i, simplify.simplify(t, unknownAs));
     }
   }
 
+  /**
+   * Decides whether the given node could be used as a predicate during the 
simplification
+   * of other OR operands.
+   */
+  private boolean allowedAsPredicateDuringOrSimplification(final RexNode t) {
+    Predicate predicate = Predicate.of(t);
+    if (predicate == null) {
+      return false;
+    }
+    /** Inequalities are not supported. */
+    SqlKind kind = t.getKind();
+    if (!SqlKind.COMPARISON.contains(kind)) {
+      return true;
+    }
+    switch (kind) {
+    case LESS_THAN:
+    case GREATER_THAN:
+    case GREATER_THAN_OR_EQUAL:
+    case LESS_THAN_OR_EQUAL:
+      return false;
+    default:
+      return true;
+    }
+  }
+
   private RexNode simplifyNot(RexCall call, RexUnknownAs unknownAs) {
     final RexNode a = call.getOperands().get(0);
     switch (a.getKind()) {
diff --git a/core/src/test/java/org/apache/calcite/test/RexProgramTest.java 
b/core/src/test/java/org/apache/calcite/test/RexProgramTest.java
index d79c133..e75c5e1 100644
--- a/core/src/test/java/org/apache/calcite/test/RexProgramTest.java
+++ b/core/src/test/java/org/apache/calcite/test/RexProgramTest.java
@@ -2704,6 +2704,18 @@ public class RexProgramTest extends 
RexProgramBuilderBase {
     assertThat(e.toString(), is("IN(?0.int0, 1, 2)"));
   }
 
+  /** Unit test for
+   * <a 
href="https://issues.apache.org/jira/browse/CALCITE-3192";>[CALCITE-3192]
+   * Simplify OR incorrectly weaks condition</a>. */
+  @Test public void testOrSimplificationNotWeakensCondition() {
+    // "1 < a or (a < 3 and b = 2)" can't be simplified
+    checkSimplifyUnchanged(
+        or(
+            lt(literal(1), vIntNotNull()),
+            and(
+                lt(vIntNotNull(), literal(3)),
+                vBoolNotNull(2))));
+  }
 }
 
 // End RexProgramTest.java
diff --git 
a/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml 
b/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml
index 79aa0ea..73e0ea6 100644
--- a/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml
+++ b/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml
@@ -4955,7 +4955,7 @@ LogicalProject(EXPR$0=[1])
       LogicalProject(DEPTNO=[$7])
         LogicalFilter(condition=[>($7, 10)])
           LogicalTableScan(table=[[CATALOG, SALES, EMP]])
-    LogicalFilter(condition=[>($7, 7)])
+    LogicalFilter(condition=[OR(>($7, 7), >($7, 10))])
       LogicalTableScan(table=[[CATALOG, SALES, EMP]])
 ]]>
         </Resource>
@@ -5275,7 +5275,7 @@ LogicalProject(EXPR$0=[1])
       LogicalProject(DEPTNO=[$7])
         LogicalFilter(condition=[>($7, 1)])
           LogicalTableScan(table=[[CATALOG, SALES, EMP]])
-    LogicalFilter(condition=[OR(>($7, 7), >($7, 1))])
+    LogicalFilter(condition=[OR(>($7, 7), >($7, 10), >($7, 1))])
       LogicalTableScan(table=[[CATALOG, SALES, EMP]])
 ]]>
         </Resource>