[ApacheDS] Range queries for version numbers (major.minor.micro)

[Marcel Bruch <ma...@codetrails.com>]

Hi directory-users,

another question regarding the use of Apache DS as knowledge base data store. 

One of our needs is to allow range queries over (Maven or OSGI like) software versions. We might have entities with DNs like these:

groupId=commons, artifactId=lang, version=2.0.1
groupId=commons, artifactId=lang, version=2.1.1
groupId=commons, artifactId=lang, version=2.2.2
groupId=commons, artifactId=lang, version=3.0.0

Queries we want to answer are:

Give me the entry with the minimum version in the range [2.0.5,3.0.0) which should return 2.1.1.
Same with a maximum range: When querying for max of [2.0.5,*)  it should return 3.0.0.

Can the support for such queries be built-in into Apache DS or would have to implement this in our application logic?

Thanks,
Marcel

Re: [ApacheDS] Range queries for version numbers (major.minor.micro)

[Emmanuel Lécharny <el...@gmail.com>]

Le 3/4/14 1:51 PM, Marcel Bruch a écrit :
> Hi directory-users,
>
> another question regarding the use of Apache DS as knowledge base data store. 
>
> One of our needs is to allow range queries over (Maven or OSGI like) software versions. We might have entities with DNs like these:
>
> groupId=commons, artifactId=lang, version=2.0.1
> groupId=commons, artifactId=lang, version=2.1.1
> groupId=commons, artifactId=lang, version=2.2.2
> groupId=commons, artifactId=lang, version=3.0.0
>
> Queries we want to answer are:
>
> Give me the entry with the minimum version in the range [2.0.5,3.0.0) which should return 2.1.1.

In LDAP, this is not possible. You can only select the entries within an
interval using a filter like :

(& (version>=2.0.5) (version<=2.0.0))

but you will get 2.1.1, 2.2.2 and 3.0.0 as a result of such a request,
and you will have to select your version.

> Same with a maximum range: When querying for max of [2.0.5,*)  it should return 3.0.0.
Same answer, the filter is just simpler :

(version >= 2.0.5)
>
> Can the support for such queries be built-in into Apache DS or would have to implement this in our application logic?
Right now, it has to be implemented in your application logic.

However, and this is a funny coincidence, we were discussing this
morning with a fellow developper who want to implements such lookup
using FCAs and I suggested to extend the filters to add something like :

(best A B C)

It would be interesting to have a filter like :

(min (& (version>=2.0.5) (version<=2.0.0)) )

which select the minimum value our of the selected ones...

Clearly a extension to LDAP.


-- 
Regards,
Cordialement,
Emmanuel Lécharny
www.iktek.com