SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 5)
   ExpressionList (children 2)
    Subquery (alias uuid) (children 1)
     SelectWithUnionQuery (children 1)
      ExpressionList (children 1)
       SelectQuery (children 3)
        ExpressionList (children 1)
         Identifier uuid
        TablesInSelectQuery (children 1)
         TablesInSelectQueryElement (children 1)
          TableExpression (children 1)
           TableIdentifier system.tables
        Function and (children 1)
         ExpressionList (children 2)
          Function equals (children 1)
           ExpressionList (children 2)
            Identifier database
            Function currentDatabase (children 1)
             ExpressionList
          Function equals (children 1)
           ExpressionList (children 2)
            Identifier table
            Literal \'t_ind_merge_2\'
    Function arrayElement (alias groups) (children 1)
     ExpressionList (children 2)
      Function extractAllGroupsVertical (children 1)
       ExpressionList (children 2)
        Identifier message
        Literal \'containing (\\\\d+) columns \\\\((\\\\d+) merged, (\\\\d+) gathered\\\\)\'
      Literal UInt64_1
   ExpressionList (children 3)
    Function arrayElement (alias total) (children 1)
     ExpressionList (children 2)
      Identifier groups
      Literal UInt64_1
    Function arrayElement (alias merged) (children 1)
     ExpressionList (children 2)
      Identifier groups
      Literal UInt64_2
    Function arrayElement (alias gathered) (children 1)
     ExpressionList (children 2)
      Identifier groups
      Literal UInt64_3
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.text_log
   Function and (children 1)
    ExpressionList (children 2)
     Function or (children 1)
      ExpressionList (children 2)
       Function equals (children 1)
        ExpressionList (children 2)
         Identifier query_id
         Function concat (children 1)
          ExpressionList (children 2)
           Identifier uuid
           Literal \'::all_1_2_1\'
       Function equals (children 1)
        ExpressionList (children 2)
         Identifier query_id
         Function concat (children 1)
          ExpressionList (children 2)
           Function currentDatabase (children 1)
            ExpressionList
           Literal \'.t_ind_merge_2::all_1_2_1\'
     Function notEmpty (children 1)
      ExpressionList (children 1)
       Identifier groups
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier event_time_microseconds
