[core] Fix FieldCountAgg null value init process (apache#3536)

yuzelin · Jun 19, 2024 · 48b0828 · 48b0828
1 parent a0558f1
commit 48b0828
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Showing 2 changed files with 7 additions and 6 deletions.
diff --git a/paimon-core/src/main/java/org/apache/paimon/mergetree/compact/aggregate/FieldCountAgg.java b/paimon-core/src/main/java/org/apache/paimon/mergetree/compact/aggregate/FieldCountAgg.java
@@ -38,7 +38,7 @@ String name() {
     public Object agg(Object accumulator, Object inputField) {
         Object count;
         if (accumulator == null || inputField == null) {
-            count = (accumulator == null ? 1 : accumulator);
+            count = (accumulator == null ? (inputField == null ? 0 : 1) : accumulator);
         } else {
             // ordered by type root definition
             switch (fieldType.getTypeRoot()) {
@@ -59,7 +59,7 @@ public Object agg(Object accumulator, Object inputField) {
     public Object retract(Object accumulator, Object inputField) {
         Object count;
         if (accumulator == null || inputField == null) {
-            count = (accumulator == null ? 1 : accumulator);
+            count = (accumulator == null ? (inputField == null ? 0 : -1) : accumulator);
         } else {
             // ordered by type root definition
             switch (fieldType.getTypeRoot()) {

diff --git a/...core/src/test/java/org/apache/paimon/mergetree/compact/aggregate/FieldAggregatorTest.java b/...core/src/test/java/org/apache/paimon/mergetree/compact/aggregate/FieldAggregatorTest.java
@@ -155,10 +155,11 @@ public void testFieldSumIntAgg() {
     @Test
     public void testFieldCountIntAgg() {
         FieldCountAgg fieldCountAgg = new FieldCountAgg(new IntType());
-        assertThat(fieldCountAgg.agg(null, 10)).isEqualTo(1);
-        assertThat(fieldCountAgg.agg(1, 5)).isEqualTo(2);
-        assertThat(fieldCountAgg.agg(2, 15)).isEqualTo(3);
-        assertThat(fieldCountAgg.agg(3, 25)).isEqualTo(4);
+        assertThat(fieldCountAgg.agg(null, null)).isEqualTo(0);
+        assertThat(fieldCountAgg.agg(1, null)).isEqualTo(1);
+        assertThat(fieldCountAgg.agg(null, 15)).isEqualTo(1);
+        assertThat(fieldCountAgg.agg(1, 0)).isEqualTo(2);
+        assertThat(fieldCountAgg.agg(3, 6)).isEqualTo(4);
     }
 
     @Test