Explain EXPLAIN ESTIMATE (children 1)
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 3)
     Function equals (children 1)
      ExpressionList (children 2)
       Literal UInt64_0
       Literal UInt64_1048577
     Literal NULL
     Function groupBitmapOr (children 1)
      ExpressionList (children 1)
       Function bitmapBuild (children 1)
        ExpressionList (children 1)
         Function array (children 1)
          ExpressionList (children 1)
           Function toInt32 (children 1)
            ExpressionList (children 1)
             Literal UInt64_65537
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Function cluster (children 1)
        ExpressionList (children 1)
         Identifier test_cluster_two_shards
    Function equals (children 1)
     ExpressionList (children 2)
      Literal NULL
      Literal UInt64_1048575
