[pizza234]

Watch out, the extension does not create "temporary indices". They can't be used in queries.

It only creates virtual indices, whose only purpose is to observe how the query optimizer would behave, if they were real.

I find it quite a curious idea, although an important parameter of the indices is the cardinality, which I don't see customizable.

[kbenson]

Yes, in this case hypothetical means conjecture. "Let's get information about how the system would function if there existed an index as such..."