add some log about implicit cast

dbms/src/Flash/Coprocessor/DAGExpressionAnalyzer.cpp

@@ -45,10 +45,11 @@ static String genFuncString(const String & func_name, const Names & argument_nam
 }
 
 DAGExpressionAnalyzer::DAGExpressionAnalyzer(const NamesAndTypesList & source_columns_, const Context & context_)
-    : source_columns(source_columns_), context(context_)
+    : source_columns(source_columns_), context(context_), log(&Logger::get("DAGExpressionAnalyzer"))
 {
     settings = context.getSettings();
     after_agg = false;
+    implicit_cast_count = 0;
 }
 
 void DAGExpressionAnalyzer::appendAggregation(
@@ -253,6 +254,9 @@ String DAGExpressionAnalyzer::appendCastIfNeeded(const tipb::Expr & expr, Expres
         // todo ignore nullable info??
         if (expected_type->getName() != actual_type->getName())
         {
+            LOG_DEBUG(
+                log, __PRETTY_FUNCTION__ << " Add implicit cast: from " << actual_type->getName() << " to " << expected_type->getName());
+            implicit_cast_count++;
             // need to add cast function
             // first construct the second argument
             tipb::Expr type_expr;

dbms/src/Flash/Coprocessor/DAGExpressionAnalyzer.h

@@ -32,6 +32,8 @@ class DAGExpressionAnalyzer : private boost::noncopyable
     Settings settings;
     const Context & context;
     bool after_agg;
+    Int32 implicit_cast_count;
+    Poco::Logger * log;
 
 public:
     DAGExpressionAnalyzer(const NamesAndTypesList & source_columns_, const Context & context_);
@@ -54,6 +56,7 @@ class DAGExpressionAnalyzer : private boost::noncopyable
     const NamesAndTypesList & getCurrentInputColumns();
     void makeExplicitSet(const tipb::Expr & expr, const Block & sample_block, bool create_ordered_set, const String & left_arg_name);
     String applyFunction(const String & func_name, Names & arg_names, ExpressionActionsPtr & actions);
+    Int32 getImplicitCastCount() { return implicit_cast_count; };
 };
 
 } // namespace DB

dbms/src/Flash/Coprocessor/InterpreterDAG.cpp

@@ -514,6 +514,9 @@ BlockIO InterpreterDAG::execute()
 
     BlockIO res;
     res.in = pipeline.firstStream();
+
+    LOG_DEBUG(
+        log, __PRETTY_FUNCTION__ << " Convert DAG request to BlockIO, adding " << analyzer->getImplicitCastCount() << " implicit cast");
     return res;
 }
 } // namespace DB