> What happens if every query has an explicit list of fields to return in > results, and the list of fields does NOT include this field that > contains a large amount of data in docValues? Does this mean that the > docValues data for the field I've mentioned is never read, and has no > effect on OS disk cache efficiency?
That is my understanding. On Fri, Jan 13, 2017 at 5:29 AM, Shawn Heisey <[email protected]> wrote: > I have an idea for a Solr feature, but to know whether it's at all > viable, I need a question about Lucene operation answered. > > In recent versions of Solr, if a field is not stored, not indexed, but > does have docValues, the originally indexed data sent for that field > will be returned in search results. In older versions (not sure which > ones) a field must be stored to be returned. > > Let's say that such a field contains a very large amount of data in > every document. Normally, this would affect OS disk cache efficiency > for general queries, because the docValues data for the field would need > to be read in order to be included in search results. Reading that > large amount of data can pollute the disk cache. If the system is in a > low-memory situation, that can affect performance. > > What happens if every query has an explicit list of fields to return in > results, and the list of fields does NOT include this field that > contains a large amount of data in docValues? Does this mean that the > docValues data for the field I've mentioned is never read, and has no > effect on OS disk cache efficiency? Or would Lucene read the docValues > data even though it doesn't include it in results? > > Thanks, > Shawn > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
