pg wire bypasses rpc layer and doesn't perform attach call (#1916)

Author: dcherednik

ydb/core/kqp/proxy_service/kqp_proxy_service.cpp

@@ -654,7 +654,11 @@ class TKqpProxyService : public TActorBootstrapped<TKqpProxyService> {
         if (queryType == NKikimrKqp::QUERY_TYPE_SQL_GENERIC_QUERY ||
             queryType == NKikimrKqp::QUERY_TYPE_SQL_GENERIC_CONCURRENT_QUERY) {
 
-            if (explicitSession && sessionInfo && !sessionInfo->AttachedRpcId) {
+            if (explicitSession &&
+                sessionInfo &&
+                !sessionInfo->PgWire && // pg wire bypasses rpc layer and doesn't perform attach
+                !sessionInfo->AttachedRpcId)
+            {
                 TString error = "Attempt to execute query on explicit session without attach";
                 ReplyProcessError(Ydb::StatusIds::BAD_REQUEST, error, requestId);
                 return;