Thank you for your reply, I did see the website (reason to use the merge indexes). However, individual cores do not have duplicates and the two cores dont have common records. So I am not sure why there are duplicates.
One of them is a sitecore core and the other one is a SQL db. They both have different _uniquekey. So looks like just from the individual cores I see duplicate rows when I do the merge. Core 1 <_uniquekey>9105</_uniquekey> <_uniquekey>9106</_uniquekey> <_uniquekey>9107</_uniquekey> Core 2 <_uniquekey>sitecore://web/{9ee61bd5-6a08-490a-bd9d-50c48a23b518}?lang=en&ver=1&ndx=sitecore_web_index</_uniquekey> <_uniquekey>sitecore://web/{46b6bcd8-8b29-4e61-8207-058e26bf622c}?lang=en&ver=1&ndx=sitecore_web_index</_uniquekey> Merged core - Core 3 <_uniquekey>9105</_uniquekey> <_uniquekey>9105</_uniquekey> <_uniquekey>sitecore://web/{9ee61bd5-6a08-490a-bd9d-50c48a23b518}?lang=en&ver=1&ndx=sitecore_web_index</_uniquekey> <_uniquekey>sitecore://web/{9ee61bd5-6a08-490a-bd9d-50c48a23b518}?lang=en&ver=1&ndx=sitecore_web_index</_uniquekey> <_uniquekey>sitecore://web/{46b6bcd8-8b29-4e61-8207-058e26bf622c}?lang=en&ver=1&ndx=sitecore_web_index</_uniquekey> <_uniquekey>9106</_uniquekey> <_uniquekey>9107</_uniquekey> <_uniquekey>9107</_uniquekey> So I am not sure what is going on... Thanks again! -- View this message in context: http://lucene.472066.n3.nabble.com/Solr-5-4-1-Mergeindexes-duplicate-rows-tp4275153p4275160.html Sent from the Solr - User mailing list archive at Nabble.com.