Core: Make totalRecordCount optional in PartitionStats

Author: ajantha-bhat

core/src/main/java/org/apache/iceberg/PartitionStats.java

@@ -33,7 +33,7 @@ public class PartitionStats implements StructLike {
   private int positionDeleteFileCount;
   private long equalityDeleteRecordCount;
   private int equalityDeleteFileCount;
-  private long totalRecordCount;
+  private Long totalRecordCount; // null by default
   private Long lastUpdatedAt; // null by default
   private Long lastUpdatedSnapshotId; // null by default
 
@@ -78,7 +78,16 @@ public int equalityDeleteFileCount() {
     return equalityDeleteFileCount;
   }
 
+  /**
+   * @deprecated since 1.8.0, will be removed in 1.9.0, use {@link #totalRecordCountOptional()}
+   *     instead.
+   */
+  @Deprecated
   public long totalRecordCount() {
+    return totalRecordCount == null ? 0 : totalRecordCount;
+  }
+
+  public Long totalRecordCountOptional() {
     return totalRecordCount;
   }
 
@@ -150,7 +159,12 @@ public void appendStats(PartitionStats entry) {
     this.positionDeleteFileCount += entry.positionDeleteFileCount;
     this.equalityDeleteRecordCount += entry.equalityDeleteRecordCount;
     this.equalityDeleteFileCount += entry.equalityDeleteFileCount;
-    this.totalRecordCount += entry.totalRecordCount;
+
+    if (totalRecordCount == null) {
+      this.totalRecordCount = entry.totalRecordCount;
+    } else {
+      this.totalRecordCount += entry.totalRecordCount;
+    }
 
     if (entry.lastUpdatedAt != null) {
       updateSnapshotInfo(entry.lastUpdatedSnapshotId, entry.lastUpdatedAt);
@@ -236,8 +250,7 @@ public <T> void set(int pos, T value) {
         this.equalityDeleteFileCount = value == null ? 0 : (int) value;
         break;
       case 9:
-        // optional field as per spec, implementation initialize to 0 for counters
-        this.totalRecordCount = value == null ? 0L : (long) value;
+        this.totalRecordCount = (Long) value;
         break;
       case 10:
         this.lastUpdatedAt = (Long) value;

core/src/test/java/org/apache/iceberg/TestPartitionStatsUtil.java

@@ -417,7 +417,7 @@ private static void computeAndValidatePartitionStats(Table testTable, Tuple... e
             PartitionStats::positionDeleteFileCount,
             PartitionStats::equalityDeleteRecordCount,
             PartitionStats::equalityDeleteFileCount,
-            PartitionStats::totalRecordCount,
+            PartitionStats::totalRecordCountOptional,
             PartitionStats::lastUpdatedAt,
             PartitionStats::lastUpdatedSnapshotId)
         .containsExactlyInAnyOrder(expectedValues);