Hi,

I am trying to find out if it is possible to apply a boost (or perhaps there is some other mechanism) to a hibernate search such that more 'recent' results have a greater score (importance) than older ones.

I appreciate that I can do date ranged searches, and that I can easily just sort the results by date, but I am aiming for something more sophisticated than that.

Ideally I would like to apply just a small boost to weight the results slightly towards the more recent - meaning that it is not impossible for a very old result to be at the top of the list - just that the old result would have to be more relevant than than another, more recent, result.

I hope I've explained my question properly - I appreciate any suggestions you may have.

Thanks,

James.

I think in your case boosting a field is not what you want. Boosting at indexing or query time will increase the relevance of a match within this field in relation to other fields. Hence boosting really only makes sense in a multi field (term) query.

What is wrong with a sorting the results by date? Why is this not sophisticated enough ;-) ?

you also have to consider that a boost factor is a constant value you apply once at indexing time. You could boost your date field and just keep increasing the value so that new entries get as higher boost factor. But what happens at a overflow? Alternatively you could at each new addition calculate a max boost factor for the latest entry and then reindex all your data giving each entry a somehow lower boost factor than your calculated max boost. Both options don't seem to be too sophisticated.

Using ehcache with an eviction policy of LRU (least recently used, which I believe it's the default) would achieve just that.