Index advisor suggesting a non-optimal index

I have a query that looks like this:

SELECT * FROM example WHERE META().id > "2ebf1fe2-a5b3-48dd-a5e5-051958f81902" AND _class = "org.example.Example" ORDER BY META().id ASC LIMIT 1000

The index advisor is advising an index that looks like this:

CREATE INDEX adv_class ON example(_class)

With the advised index the query takes 10s+ with some 600k documents.

with a manually created index

CREATE INDEX manual_index ON example(_class,(meta().id))

the query takes only around 50ms. Why does the index advisor suggest such index?

META().id is document key. It is special case because index has implicitly document key as part of non-index keys (i.e. predicate pushdown, order can’t be used). Adding again makes index wider. But some cases in secondary index adding part of index keys (when present in predicate on document key, order ) out weight the wider index. Track via MB-42920