wait time has been added (#16415)

Author: dorooleg

ydb/core/tx/columnshard/engines/reader/actor/actor.cpp

@@ -75,6 +75,9 @@ void TColumnShardScan::Bootstrap(const TActorContext& ctx) {
 }
 
 void TColumnShardScan::HandleScan(NColumnShard::TEvPrivate::TEvTaskProcessedResult::TPtr& ev) {
+    if (ChunksLimiter.HasMore()) {
+        WaitTime = TInstant::Now() - StartWaitTime;
+    }
     auto g = Stats->MakeGuard("task_result");
     auto result = ev->Get()->ExtractResult();
     if (result.IsFail()) {
@@ -91,6 +94,7 @@ void TColumnShardScan::HandleScan(NColumnShard::TEvPrivate::TEvTaskProcessedResu
 }
 
 void TColumnShardScan::HandleScan(NKqp::TEvKqpCompute::TEvScanDataAck::TPtr& ev) {
+    StartWaitTime = TInstant::Now();
     auto g = Stats->MakeGuard("ack");
 
     AFL_VERIFY(!AckReceivedInstant);
@@ -388,6 +392,7 @@ bool TColumnShardScan::SendResult(bool pageFault, bool lastBatch) {
     LastResultInstant = TMonotonic::Now();
 
     Result->CpuTime = ScanCountersPool.GetExecutionDuration();
+    Result->WaitTime = WaitTime;
 
     Send(ScanComputeActorId, Result.Release(), IEventHandle::FlagTrackDelivery);   // TODO: FlagSubscribeOnSession ?
 

ydb/core/tx/columnshard/engines/reader/actor/actor.h

@@ -193,6 +193,8 @@ class TColumnShardScan: public TActorBootstrapped<TColumnShardScan>,
     ui64 PacksSum = 0;
     ui64 Bytes = 0;
     ui32 PageFaults = 0;
+    TInstant StartWaitTime;
+    TDuration WaitTime;
 };
 
 }   // namespace NKikimr::NOlap::NReader