I have a document library inside our sharepoint on-premises 2013 enterprise server. and the document library contain a cusotm column of type drop-down named "ch". currently the document library contain 6,000++ documents, while the threshold inside our farm is set to the defualt which is 5,000. Currently inside the "All items" view i am sorting the items using the ID, so end users are able to view all the documents without getting any error. but if they try to do a column-based filter or column-based sort using any of the columns such as the "ch" they will get this error, since the list exceeds the threshold and the list does not have any indexed column:-
Today I enabled the metadata navigation and filtering site feature, and inside the document library i added the "ch" to the list's Metadata Navigation's Key Filters as follow:-
Now after doing so, end users were able to do the filtering based on the "ch" column inside the navigation columns, but they will get a message "Display only the newest results below", as follow:-
so i am not sure what happened , but can i simply say that using metadata navigation inside a list is a way to bypass the list threshold? now i know that adding a column to the metadata navigation inside a list, will add it to the "Indexed Columns" automatically. but in my case i was able to filter using the "ch" directly after enabling the Metadata Navigation (before the full crawl happen) + as i know if we already has a list which exceed the threshold (as in our case), then sharepoint will not be able to index the column as the list already exceeds the threshold.. so i am not sure if using metadata navigation and filtering inside our document library will allow us to bypass the list threshold? or still we have a threshold, but in this case how end users where able to filter based on the "ch" column then?