Merge pull request #15422 from ClickHouse/query-plan-header-remove-columns

Remove column from header descriotion for EXPLAIN PLAN

src/Core/ColumnWithTypeAndName.cpp

@@ -27,7 +27,7 @@ bool ColumnWithTypeAndName::operator==(const ColumnWithTypeAndName & other) cons
 }
 
 
-void ColumnWithTypeAndName::dumpStructure(WriteBuffer & out) const
+void ColumnWithTypeAndName::dumpNameAndType(WriteBuffer & out) const
 {
     out << name;
 
@@ -35,6 +35,11 @@ void ColumnWithTypeAndName::dumpStructure(WriteBuffer & out) const
         out << ' ' << type->getName();
     else
         out << " nullptr";
+}
+
+void ColumnWithTypeAndName::dumpStructure(WriteBuffer & out) const
+{
+    dumpNameAndType(out);
 
     if (column)
         out << ' ' << column->dumpStructure();

src/Core/ColumnWithTypeAndName.h

@@ -33,6 +33,7 @@ struct ColumnWithTypeAndName
     ColumnWithTypeAndName cloneEmpty() const;
     bool operator==(const ColumnWithTypeAndName & other) const;
 
+    void dumpNameAndType(WriteBuffer & out) const;
     void dumpStructure(WriteBuffer & out) const;
     String dumpStructure() const;
 };

src/Processors/QueryPlan/IQueryPlanStep.cpp

@@ -45,7 +45,7 @@ static void doDescribeHeader(const Block & header, size_t count, IQueryPlanStep:
             settings.out << prefix;
 
         first = false;
-        elem.dumpStructure(settings.out);
+        elem.dumpNameAndType(settings.out);
         settings.out << '\n';
     }
 }

src/Processors/QueryPlan/QueryPlan.cpp

@@ -225,7 +225,7 @@ static void explainStep(
                     settings.out << "\n" << prefix << "        ";
 
                 first = false;
-                elem.dumpStructure(settings.out);
+                elem.dumpNameAndType(settings.out);
             }
         }
 

tests/queries/0_stateless/01508_explain_header.reference

+Expression (Projection)
+Header: x UInt8
+  Expression (Before ORDER BY and SELECT)
+  Header: _dummy UInt8
+          1 UInt8
+    ReadFromStorage (Read from SystemOne)
+    Header: dummy UInt8

tests/queries/0_stateless/01508_explain_header.sql

+explain header = 1 select 1 as x;