> MongoDB 6.0 adds additional capabilities to two key operators, $lookup and $graphlookup, improving JOINS and graph traversals, respectively. Both $lookup and $graphlookup now provide full support for sharded deployments.<p>> The performance of $lookup has also been upgraded. For instance, if there is an index on the foreign key and a small number of documents have been matched, $lookup can get results between 5 and 10 times faster than before. If a larger number of documents are matched, $lookup will be twice as fast as previous iterations. If there are no indexes available (and the join is for exploratory or ad hoc queries), then $lookup will yield a hundredfold performance improvement.<p>It should have been done long time ago. Better late than never.