Probably the fact that information from deleted/updated documents is still hanging around in the corpus until merged away.
The nub of the issue is that terms in deleted documents (or the replaced doc if you update) still influence tf/idf calculations. If you optimize as Binoy suggests, all of the information relating to deleted docs is removed. If this is a SolrCloud setup, you can be getting scores from different replicas of the same shard. Due to the fact that merging (which purges deleted information) can occur at different times on different replicas, the scores calculated for a particular doc might be different depending on which replica calculated it. In either setup (SolrCloud or not), background merging can change the result order by removing information associated with deleted docs. All that said, does this have _practical_ consequences or is this mostly a curiosity question? Best, Erick On Fri, Jan 15, 2016 at 5:40 AM, Binoy Dalal <binoydala...@gmail.com> wrote: > You should try debugging such queries to see how exactly they're being > executed. > That will give you an idea as to why you're seeing the results you see. > > On Fri, 15 Jan 2016, 19:05 Brian Narsi <bnars...@gmail.com> wrote: > >> We have an index of 25 fields. Currently number of records in index is >> about 120,000. We are using >> >> parser: edismax >> >> qf: contains 8 fields >> >> fq: 1 field >> >> mm = 1 >> >> qs = 6 >> >> pf: containing g 3 fields >> >> bf: containing 1 field >> >> We have noticed that sometimes results change between two searches even if >> everything is constant. >> >> What we have identified is if we reindex data and optimize it remedies the >> situation. >> >> Is that expected behavior? Or should we also look into other factors? >> >> Thanks >> > -- > Regards, > Binoy Dalal
