SQL query length

[Alan DeKok]

Spam Eater wrote:
> Problem: When I have the attribute Session-Timeout in the radcheck
> table, I get a Segmentation Fault after the query as run, no matter if
> it returns results or not.

  doc/bugs

> a) I've noticed that freeradius performs Accounting-Request when this
> attribute is set, is this normal?

  I have no idea what you mean by that.  FreeRADIUS doesn't magically
create Accounting-Requests if it sees a Session-Timeout.

> b) Is there a limit to the sql query length?

  In 1.1.x, yes.  About 253 octets in many cases.  If the queries are in
the configuration (e.g. rlm_sql_ippool), then the queries can be very long.

  In 2.0, the queries in "unlang" can be about 7k in length.

> c) Is there a limit to the field name, i.e., should I use "SELECT
> This_is_a_very_long_field_name_having_ifs_nulls_etc AS ShortFieldName"
> or is it irrelevant?

  There is no limit to field names imposed by FreeRADIUS.

> d) The particular query performs a join to another table, may this be
> the source of the problem?

  Maybe, if you're using MySQL and an old version of the server.  See
doc/ChangeLog in 1.1.7.

> e) Is it mandatory that a query returns results?

  Yes.

> f) Can I use multiple 'query' in radius.conf, using the values from a
> first query to feed the next one?

  Yes, so long as the output from a query goes into a RADIUS attribute.

  Alan DeKok.