It seems to me that it is a question of both context and the experience of the developer. If the developer knows the database well and thinks about the specifics of the query he or she is writing, then one would expect him or her to pick the best index. But, chances are that Progress would have picked the same index without any direction. If indexes change over time, it can also be the case that yesterday's best index is no longer today's best index and letting Progress make the choice will automate the change which might be difficult to locate otherwise. And, of course, letting Progress make the choice means that it might use multiple indices, which one can't do with use-index. Progress is certainly going to do better than a developer who doesn't understand the data structure very well, but then choosing the wrong index may be the least of the errors. To craft the right query, it seems that one needs to know what indexes are available.