Question on sorting

[Mathias Herberts <ma...@gmail.com>]

Hi,

I have a Solr index with an awful lot of tiny documents in it
(hundreds of millions) each having a few fields.

I can query the index without problem and retrieve results sorted on score.

I am now exploring the possibility of sorting on other fields. The
typical number of results from queries is in the 100s or 1000s, so
tiny in regard to index size.

>From what I remember of Lucene, it had (still has?) to build a
FieldCache prior to sorting, and this FieldCache contains all field
values for the field to sort on right?

My question is, is there a way around that behaviour of the field
cache, i.e. could a filter query somehow limit the values loaded in
the FieldCache?

Is there otherwise a WTH (Well Known Hack) to be able to sort on
fields when an index has lots (100s of 1000s) of values for that
field?

Any help appreciated,

Mathias.