diff --git a/src/Storages/examples/merge_selector3.cpp b/src/Storages/examples/merge_selector3.cpp
index 56620fcc2d7..dc9f62631ed 100644
--- a/src/Storages/examples/merge_selector3.cpp
+++ b/src/Storages/examples/merge_selector3.cpp
@@ -9,6 +9,7 @@
 #include <Storages/MergeTree/ActiveDataPartSet.h>
 #include <Common/formatReadable.h>
 #include <base/interpolate.h>
+#include <absl/container/flat_hash_set.h>
 
 using namespace DB;
 
@@ -56,15 +57,24 @@ struct ReplicaState
         parts_data[names_holder.back()] = std::make_pair(std::prev(it), part_data);
     }
 
-    IMergeSelector::PartsRanges getPartRangesForMerge(const std::unordered_set<std::string> & currently_merging_parts, const ActiveDataPartSet & shared_state)
+    IMergeSelector::PartsRanges getPartRangesForMerge(const absl::flat_hash_set<std::string> & currently_merging_parts, const ActiveDataPartSet & shared_state)
     {
         IMergeSelector::PartsRanges parts_ranges;
         const MergeTreePartInfo * prev_part = nullptr;
         const auto & parts = parts_without_currently_merging_parts.getPartNamesWithInfos();
+        std::cerr << "Currently merging parts: " << currently_merging_parts.size() << std::endl;
+        std::cerr << "Total parts: " << parts.size() << std::endl;
         for (const auto & [part_info, part_name] : parts)
         {
             if (currently_merging_parts.contains(part_name))
+            {
+                std::cerr << "Skip\n";
                 continue;
+            }
+            else
+            {
+                std::cerr << "No Skip\n";
+            }
 
             auto containing_part = shared_state.getContainingPart(part_info);
             if (!containing_part.empty() && containing_part != part_name)
@@ -111,7 +121,7 @@ using CurrentlyMergingPartsNames = std::unordered_set<std::string>;
 struct SharedState
 {
     ActiveDataPartSet shared_state{MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING};
-    std::unordered_set<std::string> merging_parts;
+    absl::flat_hash_set<std::string> merging_parts;
     AllReplicasState all_replicas;
     size_t currently_running_merges{0};
     uint64_t total_parts{0};
@@ -404,8 +414,8 @@ public:
         if (current_time % 1000 == 0)
         {
             std::cerr << "Total parts count: " << state.total_parts << " merges running:" << state.currently_running_merges << " time passed " << current_time / 1000 << std::endl;
-            for (auto & replica : state.all_replicas)
-                replica.second.tickAge();
+            //for (auto & replica : state.all_replicas)
+            //    replica.second.tickAge();
         }
 
         while (!tasks.empty())
@@ -442,7 +452,7 @@ public:
         }
 
         //std::cerr << "Will try to assign merge\n";
-        if (current_time % 100 == 0)
+        if (current_time % 30 == 0)
         {
             for (const auto & replica_name : replicas)
             {
@@ -450,7 +460,10 @@ public:
                 auto ranges = state.all_replicas[replica_name].getPartRangesForMerge(state.merging_parts, state.shared_state);
 
                 if (ranges.empty())
+                {
+                    std::cerr << "No ranges\n";
                     continue;
+                }
 
                 IMergeSelector::PartsRange selected_parts = selector.select(ranges, getMaxSizeToMerge());