A client of mine is using Discussion Lists in SharePoint Online and has recently noticed that Office 365 search results are showing some discussion list posts twice. Duplicates are only showing for posts which have been recently modified in some form, including: · Posts that have been modified since being created; · Posts that have been replied to, and one or more of the replies have been edited; · Posts that have been deleted (noting that only the duplicated entry appears in search results, not the original) · Posts in lists or sites that have been forcibly re-indexed
I've noticed that some of the duplicate entries appear to be for different versions of the post - for example, if the title of a post has been changed, one entry shows the new title and the other entry shows the old title.
Duplicate entries are not appearing posts that have not been modified since being created - unless the containing list or site has been forcibly re-indexed.
Duplicate entries are also not appearing for posts that have been created relatively recently, even if those posts are modified.
I have confirmed that the posts themselves are not duplicated in lists. I have also confirmed that duplicate results are showing in the standard Office 365 search results, as well as in Content Search Web Parts within the Site Collection.
This would therefore suggest an issue with SharePoint Online search crawl of modified content or SharePoint Online search results.
I am not aware of any changes made to the Site Collection or Site settings of affected sites, although there are some search customisations to the Site Collection (additional Managed Properties and two extra Result Sources defined).
I have looked at the properties returned by the SharePoint search API for the duplicate results and noticed that the DocID (integer value) is different for each result but all other properties are the same, including the PartitionId.
