SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 6)
    Identifier is_blocked
    Identifier error_count
    Identifier data_files
    Identifier data_compressed_bytes
    Identifier broken_data_files
    Identifier broken_data_compressed_bytes
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.distribution_queue
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier database
     Function currentDatabase (children 1)
      ExpressionList