Hi On Do, 2017-08-10 at 08:30 -0700, Erick Erickson wrote: > I have to confess that I know very little about the mechanics of LTR, but > I can talk a little bit about compression. > > When a stored values is retrieved for a document it is read from the > *.fdt file which is a compressed, verbatim copy of the field. DocValues > can bypass this stored data and read directly from the DV format. > There's a discussion of useDocValuesAsStored in solr/CHANGES.txt. > > The restriction of docValues is that they can only be used for > primitive types, numerics, strings and the like, specifically _not_ > fields with class="solr.TextField". > > WARNING: I have no real clue whether LTR is built to leverage > docValues fields. If you add docValues="true" to the relevant > fields you'll have to re-index completely. In fact I'd use a new > collection. > > And don't be put off by the fact that the index size on disk will grow > on disk if you add docValues, the memory is MMapped to OS > disk space and will actually _reduce_ your JVM requirements.
Yes, DocValues are definitely on our list of things to test. Regards, Sebastian -- Sebastian Klemke Senior Software Engineer ResearchGate GmbH Invalidenstr. 115, 10115 Berlin, Germany www.researchgate.net Registered Seat: Hannover, HR B 202837 Managing Directors: Dr Ijad Madisch, Dr Sören Hofmayer VAT-ID: DE258434568 A proud affiliate of: ResearchGate Corporation, 350 Townsend St #754, San Francisco, CA 94107
