Hi I'd like to extend Lucene's FieldCache such that it will read native values from a different place (in my case, payloads). That is, instead of iterating on a field's terms and parsing each String to long (for example), I'd like to iterate over one term (sort:long, again - an example) and decode each payload value to long, and store it in the cache. The reason I want to extend Lucene's FieldCache is because I'd like Lucene to take care of updating this cache when necessary (such as after reopen for example). This will allow me to use Lucene's Sort option more easily.
I noticed Sort can be extended by providing a CUSTOM SortField, but that forces me to create Comparable objects, which is much more expensive than native longs (40 bytes vs. 8 bytes). I didn't find a way though to extend FieldCache, or ExtendedFieldCache --> even though both are extendable, I don't find the place where they're given as input to TopFieldDocCollector, FieldSortedHitQueue etc. Perhaps I'm missing it? I need to do it on top of 2.4.1, but if it's not possible and something was done in 2.9 (which I missed) in that regard I'd be happy to get a pointer to that. Today, I use this payload to implement sorting, which is memory efficient for very large indexes, but for small indexes I think Lucene's built-in sort will perform better. BTW, if it interests anyone, perhaps augmenting Lucene's sort w/ reading values from a Payload, or doing a complete payload-based-sort, I can work up a patch ... Thanks Shai
