: Subject: Efficient date-based results sorting
Sorting on anything but score is done pretty much the exact same way
regardless of data type. The one thing you can do to make any sorting on
any field more efficient is to try and reduce the cardinality of the field
-- ie: reduce the number of unique indexed terms.
With date based fields, that means that if you don't care about
millisecond granularity when you sort by date, round to the nearest second
when you index that field. if you don't care about second granularity,
round to the nearest minute, etc.
I suppose there is also this issue...
http://issues.apache.org/jira/browse/SOLR-440
...if someone implemnts a new DateField class that uses SortableLong as
the underlying format instead of string you can be more *memory*
efficient, but the speed of sorted queries will be about the same.
-Hoss
