Fix group-sorted optimization for data types with different equal values

katzyn · katzyn · commit 0ebf1422aff6 · 2022-01-04T22:14:21.000+08:00
diff --git a/h2/src/main/org/h2/command/Prepared.java b/h2/src/main/org/h2/command/Prepared.java
@@ -444,7 +444,7 @@ public void setCteCleanups(List<TableView> cteCleanups) {
         this.cteCleanups = cteCleanups;
     }
 
-    public SessionLocal getSession() {
+    public final SessionLocal getSession() {
         return session;
     }
 
diff --git a/h2/src/main/org/h2/command/query/Select.java b/h2/src/main/org/h2/command/query/Select.java
@@ -1884,9 +1884,10 @@ protected Value[] fetchNextRow() {
                 setCurrentRowNumber(rowNumber + 1);
                 if (isConditionMet()) {
                     rowNumber++;
-                    Value[] keyValues = new Value[groupIndex.length];
+                    int groupSize = groupIndex.length;
+                    Value[] keyValues = new Value[groupSize];
                     // update group
-                    for (int i = 0; i < groupIndex.length; i++) {
+                    for (int i = 0; i < groupSize; i++) {
                         int idx = groupIndex[i];
                         Expression expr = expressions.get(idx);
                         keyValues[i] = expr.getValue(getSession());
@@ -1896,10 +1897,16 @@ protected Value[] fetchNextRow() {
                     if (previousKeyValues == null) {
                         previousKeyValues = keyValues;
                         groupData.nextLazyGroup();
-                    } else if (!Arrays.equals(previousKeyValues, keyValues)) {
-                        row = createGroupSortedRow(previousKeyValues, columnCount);
-                        previousKeyValues = keyValues;
-                        groupData.nextLazyGroup();
+                    } else {
+                        SessionLocal session = getSession();
+                        for (int i = 0; i < groupSize; i++) {
+                            if (session.compare(previousKeyValues[i], keyValues[i]) != 0) {
+                                row = createGroupSortedRow(previousKeyValues, columnCount);
+                                previousKeyValues = keyValues;
+                                groupData.nextLazyGroup();
+                                break;
+                            }
+                        }
                     }
                     groupData.nextLazyRow();
                     updateAgg(columnCount, DataAnalysisOperation.STAGE_GROUP);
diff --git a/h2/src/test/org/h2/test/scripts/queries/query-optimisations.sql b/h2/src/test/org/h2/test/scripts/queries/query-optimisations.sql
@@ -175,3 +175,36 @@ SET TIME ZONE LOCAL;
 
 DROP TABLE A, B;
 > ok
+
+CREATE TABLE TEST(T TIMESTAMP WITH TIME ZONE) AS VALUES
+    NULL,
+    TIMESTAMP WITH TIME ZONE '2020-01-01 00:00:00+00',
+    TIMESTAMP WITH TIME ZONE '2020-01-01 01:00:00+01',
+    TIMESTAMP WITH TIME ZONE '2020-01-01 02:00:00+01',
+    NULL;
+> ok
+
+SELECT T AT TIME ZONE 'UTC' FROM TEST GROUP BY T;
+> T AT TIME ZONE 'UTC'
+> ----------------------
+> 2020-01-01 00:00:00+00
+> 2020-01-01 01:00:00+00
+> null
+> rows: 3
+
+CREATE INDEX TEST_T_IDX ON TEST(T);
+> ok
+
+SELECT T AT TIME ZONE 'UTC' FROM TEST GROUP BY T;
+> T AT TIME ZONE 'UTC'
+> ----------------------
+> 2020-01-01 00:00:00+00
+> 2020-01-01 01:00:00+00
+> null
+> rows: 3
+
+EXPLAIN SELECT T AT TIME ZONE 'UTC' FROM TEST GROUP BY T;
+>> SELECT "T" AT TIME ZONE 'UTC' FROM "PUBLIC"."TEST" /* PUBLIC.TEST_T_IDX */ GROUP BY "T" /* group sorted */
+
+DROP TABLE TEST;
+> ok

Original file line number	Diff line number	Diff line change
`@@ -444,7 +444,7 @@ public void setCteCleanups(List<TableView> cteCleanups) {`
`444`	`444`	`this.cteCleanups = cteCleanups;`
`445`	`445`	`}`
`446`	`446`
`447`		`- public SessionLocal getSession() {`
	`447`	`+ public final SessionLocal getSession() {`
`448`	`448`	`return session;`
`449`	`449`	`}`
`450`	`450`