In MatchAllPartial mode, the MDEX Engine first uses MatchAll mode to return results matching all search terms, if any are available.

If no such MatchAll results are available, the MDEX Engine returns the results that MatchPartial would have produced. This enables a more conservative matching policy than MatchPartial, because high-quality conjunctive results are returned if they exist and MatchPartial results are used as a fallback on conjunctive misses.

This behavior, however, can be affected if cross-field matches are applied to the search interface. A search that matches "any" or "partial" inside of the same-field might be returned before a search that matches "all" of the terms but has to cross field boundaries to do so.

In addition, spell correction can also alter the results. A search that matches any or partial spell-corrected in a same field may return before a non-spell-corrected search that matches all terms in different fields. To the user, this looks like there were no records matching all of the terms, even though there may be many that match cross-field.