http://wmj5kiicroak3dvoelipkcqobw7kwtltbqnmuv576l6x4b56b6dvmdad.onion/help/integration/advanced_search/elasticsearch.md
Deleted documents Whenever a change or deletion is made to an indexed GitLab object (a merge request description is changed, a file is deleted from the default branch in a repository, a project is deleted, etc), a document in the index is deleted. However, because these are "soft" deletes, the overall number of "deleted documents", and therefore wasted space, increases. Elasticsearch does intelligent merging of segments to remove these deleted documents.