[tmql-wg] tmql as xtm output

Lars Marius Garshol larsga@ontopia.net
Thu, 24 Jun 2004 12:00:36 +0200

Hi Stefan,

* Stefan Henke
| I=B4m currently working on a project that allows an application to
| send topicmap queries to a remote topicmap engine. As query language
| I use tolog in tm4j as it is already available. I=B4m looking for a
| way (maybe the best one ;-)) to serialize the results of the query
| to a "streamable" format to be able to transfer it over the wire. I
| thought of using xtm as it is a standard interchange format for
| topic maps.

I've been in exactly the same position and adopted XTM Fragments for
this. The idea is relatively simple: for each topic in the query
result, include its complete XTM fragment in the output. This has
worked pretty well for me.

<URL: http://www.ontopia.net/topicmaps/materials/xtm-fragments.html >

| I already discussed this issue with Kal, but I think that this is
| also interesting for people working on tmql.

It certainly is.

| In tolog there are predefined predicates which allows to execute
| some predefined operations like retrieving all base names for a
| specific topic. In this case, the resultset only contains basenames
| but no topics. I think it is not possible to create a basename in
| xtm without creating a corresponding topic. My thought was to create
| a dummy topic for each basename but this will produce a lot of
| overhead and will decrease the performance.
| What do you think?=20

I think you have no choice in this situation, and I'm not so sure that
the overhead is necessarily that bad. A more interesting question is
whether you really want to do this kind of query in a distributed

Lars Marius Garshol, Ontopian         <URL: http://www.ontopia.net >
GSM: +47 98 21 55 50                  <URL: http://www.garshol.priv.no >