I got kind of told off for not knowing the SQL explain command today.
Some say that if your database is designed properly it shouldn't be an issue. However explaining a SQL execution plan does identify the need for indexes that may not be immediately obvious.
It can identify dodgy table joins too.
SQL is 4GL and does need a helping hand at times. You can add hints to a SQL statement that force the use or non-use of indexes. You can do that in Oracle at any rate.
After thinking about it a bit, I reckon I may well have tried it before, found it pointless for the kinds of queries I have to write, and forgotten about it. Seems oddly familiar, anyway, along with a thought along the lines of "I know what my query's doing, I fucking wrote it, why don't you tell me something useful to debug this problem with".