Fix column group calculation for a single group

commit_hash:f8138b2300bb8c3beed8d27d4688beb4dc2c6f3a

1 files changed, 1 insertions, 1 deletions

diff --git a/yt/yql/providers/yt/provider/yql_yt_physical_finalizing.cpp b/yt/yql/providers/yt/provider/yql_yt_physical_finalizing.cpp
index a24102fd0c2..7fb50451cfd 100644
--- a/yt/yql/providers/yt/provider/yql_yt_physical_finalizing.cpp
+++ b/yt/yql/providers/yt/provider/yql_yt_physical_finalizing.cpp
@@ -3013,7 +3013,7 @@ private:
                                 if (!groups.empty()) {
                                     groupSpec = NYT::TNode::CreateMap();
                                     // If we keep all groups then use the group with max size as default
-                                    if (allGroups && maxGrpIt != groups.end()) {
+                                    if (allGroups && maxGrpIt != groups.end() && (groups.size() > 1 || usage.FullUsage[i])) {
                                         groupSpec["default"] = NYT::TNode::CreateEntity();
                                         groups.erase(maxGrpIt);
                                     }