Forum OpenACS Development: Re: RDF

29: Re: RDF (response to 1)
Posted by Gustaf Neumann on
Hi Jim,

i am aware of the performance issues when oo meets sql.
the particular hard problem is, where one implements
persistent objects via sql and does joins on the object
level. This would be certainly be no good idea when one
wants to use the oacs framework. There are already many
places in oacs, where a lot of small queries
(returning one tuple) originating from the tcl-api
are issued, where certainly a few "larger queries"
would be much more efficient.

The simple package does try to implement a persisten
object layer, but implements rather a class mapping.
The classes knows how to fetch, delete, update
a single item, or to retrieve a set of instances via
a single query. Currently, the retrieved values are
kept on the class level, there are no instances created
(this might change in the future, there are already to
many global variables for the communication with the
templates around).

Concerning package require: i am not talking about the
tcl package require, but about controling the order
in which oacs packages are sourced (say, an apm
package require). assume, that xotcl-core is needed
for e.g. mypackage. I have solved this so far through
the patch mentioned above, that causes to load xotcl-core
early in the bootstrap process. The same situation arises
as well, when i define a package xotcl-generic-class,
which will be needed for "someotherpackage".

I am not aware, that something has
changed in this respect in 5.2.

Concerning development in 5.2: It seems to me that
the core people are not happy about non-core
development in 5.2 before it is actually released:
This is a petty, since there a nice packages like the
assessment only available in 5.2; others are newer in 5.1:
This version-confusion is not doing any good.

Btw., i have just updated the packages above, such they
work with 5.2 now (the title attribute became ambiguous
due to the oacs data model change). I have left the version
numbers unchanged, such that the links in my note above
still point to the actual version.