Ontology-based queries

[Ashish Mahabal]

Hi Sean,

>> Whatever way is chosen, an important point to remember will be that the
>> query should magically rearrange itself so that the first clause is
>>likely
>> to return the smallest number. Otherwise if we go through a large
>>number
>> of objects only to throw away most of them at a later point, its a
>>waste
>> of resources. But perhaps this point will come up much later.

> Of course, query optimisation is essential. I would hope that this would
> be part of the reasoner's responsibility, so a client application would
> not have to worry about this (much as is the case with standard query
> engines).

However, and this is putting more onus on the tools, if someone makes a
dumb query, we will not want the resources of everybody else who also
query the same computing pool to be tied up. In case of a stand-alone
system it may not matter much, the person will just have to wait. But here
others may have to wait unnecessarily too.

A simple mechanism, at least for some "standard" query parameters could be
to store their sizes and implement the query so that smaller numbers come
first. It will go wrong sometimes, but if designed right, will save time
for all in most instances. Do any of the current, or under development,
tools have anything like this?

-ashish

Ashish Mahabal, Caltech Astronomy, Pasadena, CA 91125
http://www.astro.caltech.edu/~aam aam at astro.caltech.edu

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