From 7352a0cba06a46f99af0172bd4cc8611310bd0bc Mon Sep 17 00:00:00 2001
From: nobigo <nobigogle@gmail.com>
Date: Tue, 29 Oct 2024 08:41:32 +0800
Subject: [PATCH] [CALCITE-6649] Enhance RelMdPredicates pull up predicate from
 PROJECT

---
 .../apache/calcite/test/RelMetadataTest.java  | 39 +++++++++++
 .../apache/calcite/test/RelOptRulesTest.java  | 25 +++++++
 .../apache/calcite/test/RelOptRulesTest.xml   | 67 +++++++++++++++++++
 3 files changed, 131 insertions(+)

diff --git a/core/src/test/java/org/apache/calcite/test/RelMetadataTest.java b/core/src/test/java/org/apache/calcite/test/RelMetadataTest.java
index bbe599923dd..3392f3fa91e 100644
--- a/core/src/test/java/org/apache/calcite/test/RelMetadataTest.java
+++ b/core/src/test/java/org/apache/calcite/test/RelMetadataTest.java
@@ -2934,6 +2934,45 @@ private void checkPredicates(RelOptCluster cluster, RelOptTable empTable,
         sortsAs("[IS NULL($0), IS NULL($1)]"));
   }
 
+  /** Test case for
+   * <a href="https://issues.apache.org/jira/browse/CALCITE-6649">[CALCITE-6649]
+   * Enhance RelMdPredicates pull up predicate from PROJECT</a>. */
+  @Test void testPullUpPredicatesFromProject2() {
+    final String sql = "select comm <> 2, comm = 2 from emp where comm = 2";
+    final Project rel = (Project) sql(sql).toRel();
+    final RelMetadataQuery mq = rel.getCluster().getMetadataQuery();
+    RelOptPredicateList inputSet = mq.getPulledUpPredicates(rel);
+    ImmutableList<RexNode> pulledUpPredicates = inputSet.pulledUpPredicates;
+    assertThat(pulledUpPredicates, sortsAs("[]"));
+  }
+
+  @Test void testPullUpPredicatesFromProject3() {
+    final String sql = "select comm is null, comm is not null from emp where comm = 2";
+    final Project rel = (Project) sql(sql).toRel();
+    final RelMetadataQuery mq = rel.getCluster().getMetadataQuery();
+    RelOptPredicateList inputSet = mq.getPulledUpPredicates(rel);
+    ImmutableList<RexNode> pulledUpPredicates = inputSet.pulledUpPredicates;
+    assertThat(pulledUpPredicates, sortsAs("[=($0, false), =($1, true)]"));
+  }
+
+  @Test void testPullUpPredicatesFromProject4() {
+    final String sql = "select comm = 2, empno <> 1 from emp where comm = 2 and empno = 1";
+    final Project rel = (Project) sql(sql).toRel();
+    final RelMetadataQuery mq = rel.getCluster().getMetadataQuery();
+    RelOptPredicateList inputSet = mq.getPulledUpPredicates(rel);
+    ImmutableList<RexNode> pulledUpPredicates = inputSet.pulledUpPredicates;
+    assertThat(pulledUpPredicates, sortsAs("[]"));
+  }
+
+  @Test void testPullUpPredicatesFromProject5() {
+    final String sql = "select mgr=2, comm=2 from emp where mgr is null and empno = 1";
+    final Project rel = (Project) sql(sql).toRel();
+    final RelMetadataQuery mq = rel.getCluster().getMetadataQuery();
+    RelOptPredicateList inputSet = mq.getPulledUpPredicates(rel);
+    ImmutableList<RexNode> pulledUpPredicates = inputSet.pulledUpPredicates;
+    assertThat(pulledUpPredicates, sortsAs("[]"));
+  }
+
   /** Test case for
    * <a href="https://issues.apache.org/jira/browse/CALCITE-6599">[CALCITE-6599]
    * RelMdPredicates should pull up more predicates from VALUES
diff --git a/core/src/test/java/org/apache/calcite/test/RelOptRulesTest.java b/core/src/test/java/org/apache/calcite/test/RelOptRulesTest.java
index b0324902f1d..8fd418224cc 100644
--- a/core/src/test/java/org/apache/calcite/test/RelOptRulesTest.java
+++ b/core/src/test/java/org/apache/calcite/test/RelOptRulesTest.java
@@ -5910,6 +5910,31 @@ private HepProgram getTransitiveProgram() {
         .check();
   }
 
+  @Test void testPullUpPredicatesFromUnionWithProject() {
+    final String sql = "select empno = null from emp where comm = 2\n"
+        + "union all\n"
+        + "select comm = 2 from emp where comm = 2";
+    sql(sql).withPre(getTransitiveProgram())
+        .withRule(CoreRules.FILTER_REDUCE_EXPRESSIONS,
+            CoreRules.PROJECT_REDUCE_EXPRESSIONS)
+          .check();
+  }
+
+  @Test void testPullUpPredicatesFromProject1() {
+    final String sql = "select comm <> 2, comm = 2 from emp where comm = 2";
+    sql(sql).withPre(getTransitiveProgram())
+        .withRule(CoreRules.PROJECT_REDUCE_EXPRESSIONS)
+        .check();
+  }
+
+  @Test void testPullUpPredicatesFromProject2() {
+    final String sql = "select comm = 2, empno <> 1 from emp where comm = 2 and empno = 1";
+    sql(sql).withPre(getTransitiveProgram())
+        .withRule(CoreRules.FILTER_REDUCE_EXPRESSIONS,
+            CoreRules.PROJECT_REDUCE_EXPRESSIONS)
+        .check();
+  }
+
   /** Test case for
    * <a href="https://issues.apache.org/jira/browse/CALCITE-1995">[CALCITE-1995]
    * Remove predicates from Filter if they can be proved to be always true or
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 25520355ae7..90f22fee123 100644
--- a/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml
+++ b/core/src/test/resources/org/apache/calcite/test/RelOptRulesTest.xml
@@ -9353,6 +9353,73 @@ LogicalProject(EMPNO=[$0], ENAME=[$1], JOB=[$2], MGR=[$3], HIREDATE=[$4], SAL=[$
 LogicalProject(EMPNO=[10], ENAME=[$1], JOB=[$2], MGR=[null:INTEGER], HIREDATE=[$4], SAL=[$5], COMM=[$6], DEPTNO=[7], SLACKER=[$8])
   LogicalFilter(condition=[AND(=($7, 7), =($0, 10), IS NULL($3))])
     LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+]]>
+    </Resource>
+  </TestCase>
+  <TestCase name="testPullUpPredicatesFromProject1">
+    <Resource name="sql">
+      <![CDATA[select comm <> 2, comm = 2 from emp where comm = 2]]>
+    </Resource>
+    <Resource name="planBefore">
+      <![CDATA[
+LogicalProject(EXPR$0=[<>($6, 2)], EXPR$1=[=($6, 2)])
+  LogicalFilter(condition=[=($6, 2)])
+    LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+]]>
+    </Resource>
+    <Resource name="planAfter">
+      <![CDATA[
+LogicalProject(EXPR$0=[false], EXPR$1=[true])
+  LogicalFilter(condition=[=($6, 2)])
+    LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+]]>
+    </Resource>
+  </TestCase>
+  <TestCase name="testPullUpPredicatesFromProject2">
+    <Resource name="sql">
+      <![CDATA[select comm = 2, empno <> 1 from emp where comm = 2 and empno = 1]]>
+    </Resource>
+    <Resource name="planBefore">
+      <![CDATA[
+LogicalProject(EXPR$0=[=($6, 2)], EXPR$1=[<>($0, 1)])
+  LogicalFilter(condition=[AND(=($6, 2), =($0, 1))])
+    LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+]]>
+    </Resource>
+    <Resource name="planAfter">
+      <![CDATA[
+LogicalProject(EXPR$0=[true], EXPR$1=[false])
+  LogicalFilter(condition=[AND(=($6, 2), =($0, 1))])
+    LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+]]>
+    </Resource>
+  </TestCase>
+  <TestCase name="testPullUpPredicatesFromUnionWithProject">
+    <Resource name="sql">
+      <![CDATA[select empno = null from emp where comm = 2
+union all
+select comm = 2 from emp where comm = 2]]>
+    </Resource>
+    <Resource name="planBefore">
+      <![CDATA[
+LogicalUnion(all=[true])
+  LogicalProject(EXPR$0=[null:BOOLEAN])
+    LogicalFilter(condition=[=($6, 2)])
+      LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+  LogicalProject(EXPR$0=[=($6, 2)])
+    LogicalFilter(condition=[=($6, 2)])
+      LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+]]>
+    </Resource>
+    <Resource name="planAfter">
+      <![CDATA[
+LogicalUnion(all=[true])
+  LogicalProject(EXPR$0=[null:BOOLEAN])
+    LogicalFilter(condition=[=($6, 2)])
+      LogicalTableScan(table=[[CATALOG, SALES, EMP]])
+  LogicalProject(EXPR$0=[true])
+    LogicalFilter(condition=[=($6, 2)])
+      LogicalTableScan(table=[[CATALOG, SALES, EMP]])
 ]]>
     </Resource>
   </TestCase>