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
