Optimize isOvershadowed when there is a unique minor version for an interval (#15952)

* Optimize isOvershadowed for intervals with timechunk locking

benchmarks/src/test/java/org/apache/druid/timeline/VersionedIntervalTimelineBenchmark.java

@@ -252,6 +252,23 @@ public class VersionedIntervalTimelineBenchmark
     blackhole.consume(timeline.isOvershadowed(segment.getInterval(), segment.getVersion(), segment));
   }
 
+  @Benchmark
+  public void benchIsOvershadowedTotal(Blackhole blackhole)
+  {
+    blackhole.consume(isOvershadowedTotal());
+  }
+
+  private int isOvershadowedTotal()
+  {
+    int overshadowedCount = 0;
+    for (DataSegment segment : segments) {
+      if (timeline.isOvershadowed(segment.getInterval(), segment.getVersion(), segment)) {
+        overshadowedCount++;
+      }
+    }
+    return overshadowedCount;
+  }
+
   @Benchmark
   public void benchFindFullyOvershadowed(Blackhole blackhole)
   {

processing/src/main/java/org/apache/druid/timeline/VersionedIntervalTimeline.java

@@ -458,11 +458,16 @@ public class VersionedIntervalTimeline<VersionType, ObjectType extends Overshado
       if (entry != null) {
         final int majorVersionCompare = versionComparator.compare(version, entry.getVersion());
         if (majorVersionCompare == 0) {
+          // If the major versions of the timeline entry and target segment are equal, and
+          // the maximum minor version among the segments is not greater than the minor version of the target segment,
+          // none of the segments in the interval can overshadow it.
+          if (entry.getMaxMinorVersion() > object.getMinorVersion()) {
             for (PartitionChunk<ObjectType> chunk : entry.partitionHolder) {
               if (chunk.getObject().overshadows(object)) {
                 return true;
               }
             }
+          }
           return false;
         } else {
           return majorVersionCompare < 0;
@@ -815,6 +820,15 @@ public class VersionedIntervalTimeline<VersionType, ObjectType extends Overshado
       return partitionHolder;
     }
 
+    /**
+     * Returns the maximum minor version across all the added segments.
+     * We do not handle updates of this variable when segments are removed for the sake of simplicity.
+     */
+    private short getMaxMinorVersion()
+    {
+      return partitionHolder.getMaxMinorVersion();
+    }
+
     @Override
     public boolean equals(Object o)
     {

processing/src/main/java/org/apache/druid/timeline/partition/PartitionHolder.java

@@ -34,16 +34,24 @@ public class PartitionHolder<T extends Overshadowable<T>> implements Iterable<Pa
 {
   private final OvershadowableManager<T> overshadowableManager;
 
+  private short maxMinorVersion;
+
   public static <T extends Overshadowable<T>> PartitionHolder<T> copyWithOnlyVisibleChunks(
       PartitionHolder<T> partitionHolder
   )
   {
-    return new PartitionHolder<>(OvershadowableManager.copyVisible(partitionHolder.overshadowableManager));
+    return new PartitionHolder<>(
+        OvershadowableManager.copyVisible(partitionHolder.overshadowableManager),
+        partitionHolder.maxMinorVersion
+    );
   }
 
   public static <T extends Overshadowable<T>> PartitionHolder<T> deepCopy(PartitionHolder<T> partitionHolder)
   {
-    return new PartitionHolder<>(OvershadowableManager.deepCopy(partitionHolder.overshadowableManager));
+    return new PartitionHolder<>(
+        OvershadowableManager.deepCopy(partitionHolder.overshadowableManager),
+        partitionHolder.maxMinorVersion
+    );
   }
 
   public PartitionHolder(PartitionChunk<T> initialChunk)
@@ -60,14 +68,28 @@ public class PartitionHolder<T extends Overshadowable<T>> implements Iterable<Pa
     }
   }
 
-  protected PartitionHolder(OvershadowableManager<T> overshadowableManager)
+  protected PartitionHolder(OvershadowableManager<T> overshadowableManager, short maxMinorVersion)
   {
     this.overshadowableManager = overshadowableManager;
+    this.maxMinorVersion = maxMinorVersion;
   }
 
   public boolean add(PartitionChunk<T> chunk)
   {
-    return overshadowableManager.addChunk(chunk);
+    boolean added = overshadowableManager.addChunk(chunk);
+    if (added && chunk.getObject().getMinorVersion() > maxMinorVersion) {
+      maxMinorVersion = chunk.getObject().getMinorVersion();
+    }
+    return added;
+  }
+
+  /**
+   * Returns the maximum minor version across all the added segments.
+   * We do not handle updates of this variable when segments are removed for the sake of simplicity.
+   */
+  public short getMaxMinorVersion()
+  {
+    return maxMinorVersion;
   }
 
   @Nullable

server/src/main/java/org/apache/druid/metadata/SqlSegmentsMetadataManager.java

@@ -43,6 +43,7 @@ import org.apache.druid.java.util.common.Intervals;
 import org.apache.druid.java.util.common.JodaUtils;
 import org.apache.druid.java.util.common.MapUtils;
 import org.apache.druid.java.util.common.Pair;
+import org.apache.druid.java.util.common.Stopwatch;
 import org.apache.druid.java.util.common.StringUtils;
 import org.apache.druid.java.util.common.concurrent.Execs;
 import org.apache.druid.java.util.common.lifecycle.LifecycleStart;
@@ -1014,7 +1015,8 @@ public class SqlSegmentsMetadataManager implements SegmentsMetadataManager
   @GuardedBy("pollLock")
   private void doPoll()
   {
-    log.debug("Starting polling of segment table");
+    final Stopwatch stopwatch = Stopwatch.createStarted();
+    log.info("Starting polling of segment table");
 
     // some databases such as PostgreSQL require auto-commit turned off
     // to stream results back, enabling transactions disables auto-commit
@@ -1072,12 +1074,18 @@ public class SqlSegmentsMetadataManager implements SegmentsMetadataManager
     if (segments.isEmpty()) {
       log.info("No segments found in the database!");
     } else {
-      log.info("Polled and found %,d segments in the database", segments.size());
+      log.info("Polled and found [%,d] segments in the database in [%,d] ms.", segments.size(), stopwatch.millisElapsed());
     }
+    stopwatch.restart();
+
     dataSourcesSnapshot = DataSourcesSnapshot.fromUsedSegments(
         Iterables.filter(segments, Objects::nonNull), // Filter corrupted entries (see above in this method).
         dataSourceProperties
     );
+    log.info(
+        "Successfully created snapshot from polled segments in [%d] ms. Found [%d] overshadowed segments.",
+        stopwatch.millisElapsed(), dataSourcesSnapshot.getOvershadowedSegments().size()
+    );
   }
 
   private static ImmutableMap<String, String> createDefaultDataSourceProperties()