Changes are applied to the index writer upon transaction commits, so opening IndexReaders off IndexWriters would not allow seeing changes applied by a transaction when searching within that transaction.

However, opening IndexReaders off IndexWriters allows seeing changes without having to commit them to the index after each transaction, which is interesting because commits are very slow (compared to just applying the changes to the index writer).

This was implemented as the "near-real-time" index manager in Hibernate Search 5, and was restored in Search 6.0.0.Beta5 as part of HSEARCH-3775 Closed .

Closing.