From e277117d05b3966f059ef6b4011fc97a330e793f Mon Sep 17 00:00:00 2001
From: Dmitry Orlov <orlovorlov@yandex-team.ru>
Date: Tue, 21 May 2024 15:04:09 -0700
Subject: [PATCH] Address comment re enum pretty-printing, and add MergeJoin

---
 .../yql/core/cbo/cbo_optimizer_new.cpp        |  6 +++++-
 ydb/library/yql/core/cbo/ya.make              |  2 ++
 ydb/library/yql/core/yql_cost_function.cpp    | 20 -------------------
 ydb/library/yql/core/yql_cost_function.h      |  7 +++----
 4 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/ydb/library/yql/core/cbo/cbo_optimizer_new.cpp b/ydb/library/yql/core/cbo/cbo_optimizer_new.cpp
index 0925a3236654..ea4a2331c660 100644
--- a/ydb/library/yql/core/cbo/cbo_optimizer_new.cpp
+++ b/ydb/library/yql/core/cbo/cbo_optimizer_new.cpp
@@ -8,6 +8,9 @@
 
 #include <library/cpp/disjoint_sets/disjoint_sets.h>
 
+const TString& ToString(NYql::EJoinKind);
+const TString& ToString(NYql::EJoinAlgoType);
+
 namespace NYql {
 
 using namespace NYql::NDq;
@@ -89,7 +92,8 @@ void TJoinOptimizerNode::Print(std::stringstream& stream, int ntabs) {
         stream << "    ";
     }
 
-    stream << "Join: (" << ConvertToJoinString(JoinType) << "," << ConvertToJoinAlgoString(JoinAlgo) << ") ";
+    stream << "Join: (" << ToString(JoinType) << "," << ToString(JoinAlgo) << ") ";
+
     for (auto c : JoinConditions){
         stream << c.first.RelName << "." << c.first.AttributeName
             << "=" << c.second.RelName << "."
diff --git a/ydb/library/yql/core/cbo/ya.make b/ydb/library/yql/core/cbo/ya.make
index d0986d4f6420..15e4923b631b 100644
--- a/ydb/library/yql/core/cbo/ya.make
+++ b/ydb/library/yql/core/cbo/ya.make
@@ -4,6 +4,8 @@ SRCS(
     cbo_optimizer_new.cpp
 )
 
+GENERATE_ENUM_SERIALIZATION(cbo_optimizer_new.h)
+
 END()
 
 RECURSE_FOR_TESTS(
diff --git a/ydb/library/yql/core/yql_cost_function.cpp b/ydb/library/yql/core/yql_cost_function.cpp
index 7f0e8477d2b5..7dfe08a2cdd7 100644
--- a/ydb/library/yql/core/yql_cost_function.cpp
+++ b/ydb/library/yql/core/yql_cost_function.cpp
@@ -3,17 +3,6 @@
 
 namespace NYql {
 
-namespace {
-
-THashMap<TString,EJoinAlgoType> JoinAlgoMap = {
-    {"Undefined",EJoinAlgoType::Undefined},
-    {"LookupJoin",EJoinAlgoType::LookupJoin},
-    {"MapJoin",EJoinAlgoType::MapJoin},
-    {"GraceJoin",EJoinAlgoType::GraceJoin},
-    {"StreamLookupJoin",EJoinAlgoType::StreamLookupJoin}};
-
-}  // namespace
-
 bool NDq::operator < (const NDq::TJoinColumn& c1, const NDq::TJoinColumn& c2) {
     if (c1.RelName < c2.RelName){
         return true;
@@ -23,13 +12,4 @@ bool NDq::operator < (const NDq::TJoinColumn& c1, const NDq::TJoinColumn& c2) {
     return false;
 }
 
-TString ConvertToJoinAlgoString(EJoinAlgoType joinAlgo) {
-    for (const auto& [k,v] : JoinAlgoMap) {
-        if (v == joinAlgo) {
-            return k;
-        }
-    }
-    Y_ENSURE(false, "Unknown join algo");
-}
-
 }  // namespace NYql
diff --git a/ydb/library/yql/core/yql_cost_function.h b/ydb/library/yql/core/yql_cost_function.h
index 729faecdb6d0..778ee6276a6c 100644
--- a/ydb/library/yql/core/yql_cost_function.h
+++ b/ydb/library/yql/core/yql_cost_function.h
@@ -21,11 +21,12 @@ enum class EJoinAlgoType {
     LookupJoin,
     MapJoin,
     GraceJoin,
-    StreamLookupJoin //Right part can be updated during an operation. Used mainly for joining streams with lookup tables. Currently impplemented in Dq by LookupInputTransform
+    StreamLookupJoin, //Right part can be updated during an operation. Used mainly for joining streams with lookup tables. Currently impplemented in Dq by LookupInputTransform
+    MergeJoin  // To be used in YT
 };
 
 //StreamLookupJoin is not a subject for CBO and not not included here
-static constexpr auto AllJoinAlgos = { EJoinAlgoType::MapJoin, EJoinAlgoType::GraceJoin, EJoinAlgoType::LookupJoin };
+static constexpr auto AllJoinAlgos = { EJoinAlgoType::MapJoin, EJoinAlgoType::GraceJoin, EJoinAlgoType::LookupJoin, EJoinAlgoType::MergeJoin };
 
 namespace NDq {
 
@@ -57,6 +58,4 @@ bool operator < (const TJoinColumn& c1, const TJoinColumn& c2);
 
 }  // namespace NDq
 
-TString ConvertToJoinAlgoString(EJoinAlgoType joinAlgo);
-
 }  // namespace NYql