From bb4de829893359c3f2b40b42d61302c65ac55abb Mon Sep 17 00:00:00 2001
From: Dongjoon Hyun <dongjoon@apache.org>
Date: Thu, 19 Mar 2015 15:47:07 +0900
Subject: [PATCH] TAJO-1420: Support GROUPING SET syntax

---
 .../main/java/org/apache/tajo/algebra/Aggregation.java   | 1 +
 .../antlr4/org/apache/tajo/engine/parser/SQLParser.g4    | 9 +++++++--
 .../java/org/apache/tajo/engine/parser/SQLAnalyzer.java  | 6 +++++-
 .../org/apache/tajo/plan/algebra/BaseAlgebraVisitor.java | 2 ++
 4 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/tajo-algebra/src/main/java/org/apache/tajo/algebra/Aggregation.java b/tajo-algebra/src/main/java/org/apache/tajo/algebra/Aggregation.java
index 8bcd7e2998..084b1e3a08 100644
--- a/tajo-algebra/src/main/java/org/apache/tajo/algebra/Aggregation.java
+++ b/tajo-algebra/src/main/java/org/apache/tajo/algebra/Aggregation.java
@@ -149,6 +149,7 @@ public static enum GroupType {
     OrdinaryGroup(""),
     Cube("Cube"),
     Rollup("Rollup"),
+    GroupingSet("GroupingSet"),
     EmptySet("()");
 
     String displayName;
diff --git a/tajo-core/src/main/antlr4/org/apache/tajo/engine/parser/SQLParser.g4 b/tajo-core/src/main/antlr4/org/apache/tajo/engine/parser/SQLParser.g4
index 1a63470bf8..cd2f761e80 100644
--- a/tajo-core/src/main/antlr4/org/apache/tajo/engine/parser/SQLParser.g4
+++ b/tajo-core/src/main/antlr4/org/apache/tajo/engine/parser/SQLParser.g4
@@ -1106,7 +1106,8 @@ grouping_element_list
 grouping_element
   : rollup_list
   | cube_list
-  | empty_grouping_set
+  | grouping_set_list
+  | empty_set
   | ordinary_grouping_set
   ;
 
@@ -1127,7 +1128,11 @@ cube_list
   : CUBE LEFT_PAREN c=ordinary_grouping_set_list RIGHT_PAREN
   ;
 
-empty_grouping_set
+grouping_set_list
+  : GROUPING SET LEFT_PAREN c=ordinary_grouping_set_list RIGHT_PAREN
+  ;
+
+empty_set
   : LEFT_PAREN RIGHT_PAREN
   ;
 
diff --git a/tajo-core/src/main/java/org/apache/tajo/engine/parser/SQLAnalyzer.java b/tajo-core/src/main/java/org/apache/tajo/engine/parser/SQLAnalyzer.java
index 6d32fa5274..d0258dcb4e 100644
--- a/tajo-core/src/main/java/org/apache/tajo/engine/parser/SQLAnalyzer.java
+++ b/tajo-core/src/main/java/org/apache/tajo/engine/parser/SQLAnalyzer.java
@@ -334,7 +334,7 @@ public Aggregation visitGroupby_clause(SQLParser.Groupby_clauseContext ctx) {
     Aggregation clause = new Aggregation();
 
     // If grouping group is not empty
-    if (ctx.grouping_element_list().grouping_element().get(0).empty_grouping_set() == null) {
+    if (ctx.grouping_element_list().grouping_element().get(0).empty_set() == null) {
       int elementSize = ctx.grouping_element_list().grouping_element().size();
       ArrayList<GroupElement> groups = new ArrayList<GroupElement>(elementSize + 1);
       ArrayList<Expr> ordinaryExprs = null;
@@ -357,6 +357,10 @@ public Aggregation visitGroupby_clause(SQLParser.Groupby_clauseContext ctx) {
           groupSize++;
           groups.add(new GroupElement(GroupType.Cube,
               getRowValuePredicandsFromOrdinaryGroupingSetList(element.cube_list().c)));
+        } else if (element.grouping_set_list() != null) {
+          groupSize++;
+          groups.add(new GroupElement(GroupType.GroupingSet,
+              getRowValuePredicandsFromOrdinaryGroupingSetList(element.grouping_set_list().c)));
         }
       }
 
diff --git a/tajo-plan/src/main/java/org/apache/tajo/plan/algebra/BaseAlgebraVisitor.java b/tajo-plan/src/main/java/org/apache/tajo/plan/algebra/BaseAlgebraVisitor.java
index bd105144de..35209a7e87 100644
--- a/tajo-plan/src/main/java/org/apache/tajo/plan/algebra/BaseAlgebraVisitor.java
+++ b/tajo-plan/src/main/java/org/apache/tajo/plan/algebra/BaseAlgebraVisitor.java
@@ -350,6 +350,8 @@ public RESULT visitHaving(CONTEXT ctx, Stack<Expr> stack, Having expr) throws Pl
   public RESULT visitGroupBy(CONTEXT ctx, Stack<Expr> stack, Aggregation expr) throws PlanningException {
     stack.push(expr);
 
+    if (expr.getGroupSet() == null)
+      throw new PlanningException("Empty Group Set");
     for (org.apache.tajo.algebra.Aggregation.GroupElement groupElement : expr.getGroupSet()) {
       for (Expr groupingSet : groupElement.getGroupingSets()) {
         visit(ctx, stack, groupingSet);