For completeness this is the related issue : https://issues.apache.org/jira/browse/SOLR-8096
Cheers 2015-10-06 11:21 GMT+01:00 Alessandro Benedetti <benedetti.ale...@gmail.com> : > We should make some precision here, > When dealing with faceting , there are currently 2 main approaches : > > 1) *Enum Algorithm* - best for low cardinality value fields, it is based > on retrieving the term enum for all the terms in the index, and then > intersecting the related posting list with the query result set > > 2) *Un-Inverting Algorithms* - Best for high cardinality value fields, it > is based on uninverting the index, checking the value for each query result > document field, and counting the occurrences > > Within the 2nd approach : > > 2a) *Doc Values * - It is better for dynamic indexes, built at indexing > time and stored on the disk ( setting the specific attribute for the field) > OR calculated at runtime thanks to the UnInvertedReader that will uninvert > to an in-memory structure that looks like DocValues > > 2b) *Uninverted field* - for index that changes less frequently . After > the removal related : > Only per segment field caches are available, which means you should be > able to use it using the fcs algorithm. > > This should be the current situation, > I will take a look into details and let you know if I understood something > wrong. > > Cheers > > > > 2015-10-06 5:03 GMT+01:00 William Bell <billnb...@gmail.com>: > >> So the FieldCache was removed from Solr 5. >> >> What is the implication of this? Should we move all facets to DocValues >> when we have high cardinality (lots of values) ? Are we adding it back? >> >> Other ideas to improve performance? >> >> From Mike M: >> >> FieldCache is gone (moved to a dedicated UninvertingReader in the >> miscmodule). >> This means when you intend to sort on a field, you should index that field >> using doc values, which is much faster and less heap consuming than >> FieldCache. >> >> -- >> Bill Bell >> billnb...@gmail.com >> cell 720-256-8076 >> > > > > -- > -------------------------- > > Benedetti Alessandro > Visiting card - http://about.me/alessandro_benedetti > Blog - http://alexbenedetti.blogspot.co.uk > > "Tyger, tyger burning bright > In the forests of the night, > What immortal hand or eye > Could frame thy fearful symmetry?" > > William Blake - Songs of Experience -1794 England > -- -------------------------- Benedetti Alessandro Visiting card - http://about.me/alessandro_benedetti Blog - http://alexbenedetti.blogspot.co.uk "Tyger, tyger burning bright In the forests of the night, What immortal hand or eye Could frame thy fearful symmetry?" William Blake - Songs of Experience -1794 England
