SOLR-1632 will certainly help. But trying to predict whether your core A or core B will appear first doesn't really seem like a good use of time. If you actually have a setup like you describe, add &debug=all to your query on both cores and you'll see all the gory detail of how the scores are calculated, providing a definitive answer in _your_ situation.
Best, Erick On Mon, Mar 9, 2015 at 5:44 AM, <johnmu...@aol.com> wrote: > (reposing this to see if anyone can help) > > > Help me understand this better (regarding ranking). > > If I have two docs that are 100% identical with the exception of uid (which > is stored but not indexed). In a single core setup, if I search "xyz" such > that those 2 docs end up ranking as #1 and #2. When I switch over to two > core setup, doc-A goes to core-A (which has 10 records) and doc-B goes to > core-B (which has 100,000 records). > > Now, are you saying in 2 core setup if I search on "xyz" (just like in singe > core setup) this time I will not see doc-A and doc-B as #1 and #2 in ranking? > That is, are you saying doc-A may now be somewhere at the top / bottom far > away from doc-B? If so, which will be #1: the doc off core-A (that has 10 > records) or doc-B off core-B (that has 100,000 records)? > > If I got all this right, are you saying SOLR-1632 will fix this issue such > that the end result will now be as if I had 1 core? > > - MJ > > > -----Original Message----- > From: Toke Eskildsen [mailto:t...@statsbiblioteket.dk] > Sent: Thursday, March 5, 2015 9:06 AM > To: solr-user@lucene.apache.org > Subject: Re: Cores and and ranking (search quality) > > On Thu, 2015-03-05 at 14:34 +0100, johnmu...@aol.com wrote: >> My question is this: if I put my data in multiple cores and use >> distributed search will the ranking be different if I had all my data >> in a single core? > > Yes, it will be different. The practical impact depends on how homogeneous > your data are across the shards and how large your shards are. If you have > small and dissimilar shards, your ranking will suffer a lot. > > Work is being done to remedy this: > https://issues.apache.org/jira/browse/SOLR-1632 > >> Also, will facet and more-like-this quality / result be the same? > > It is not formally guaranteed, but for most practical purposes, faceting on > multi-shards will give you the same results as single-shards. > > I don't know about more-like-this. My guess is that it will be affected in > the same way that standard searches are. > >> Also, reading the distributed search wiki >> (http://wiki.apache.org/solr/DistributedSearch) it looks like Solr >> does the search and result merging (all I have to do is issue a >> search), is this correct? > > Yes. From a user-perspective, searches are no different. > > - Toke Eskildsen, State and University Library, Denmark >
