: If your concern is performance, faceting integers versus faceting strings, I : believe Lucene makes the differences negligible. Given that choice I'd go
>From a speed standpoint, i believe the differnece is negligable, but from a memory standpoint the datastructures for dealing with an integer field is much smaller then dealing with a string field. My recomendation: if you have a front end application that can deal with mapping categoryIds to categoryLabels easily (ie: if it's already dealing with these types of metadata for non search pages) then i would definitley facet on the categoryIds. the simplicity of faceting on a categoryLabel field (or a composite field, with teh id and label concatenated together) is really nice, but besides the memory savings of only using the intes, you can have other benefits in cases where you have no other reason for the category label to be in the index at all: like a smaller total index size, the ability to I18N your category labels, the ability to tweak the names of your categories w/o reindexing, etc... -Hoss
