SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    Identifier is_readonly
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier system.database_replicas
   Function equals (children 1)
    ExpressionList (children 2)
     Identifier database
     Literal \'db_2\'
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier database
