redis scan returns empty results but nonzero cursor

Question

I have a redis database with a few million keys. Sometimes I need to query keys by the pattern e.g. 2016-04-28:* for which I use scan. First call shoul

Answer 1

You'll always need to complete the scan (i.e. get cursor == 0) to be sure there no no matched. You can, however, use the COUNT option to reduce the number of iterations. The default value of 10 is fast If this is a common scenario with your match pattern - start increasing it (e.g. double or powers of two but put a max cap just in case) with every empty reply, to make Redis "search harder" for keys. By doing so, you'll be saving on network round trips so it should "speed things up".