Filter disregards if database supports FEATURE_TABLE_ALIAS or not

[jawngee]

Pretty minor, but I ran into this working with sqlite3 which of course supports it, though it does not support numeric ones, it must contain one letter.

[peterdm]

Do you have a testcase? I'm not sure if I understand what you encountered.

The heuristic for building table aliases is to take one letter from each word segment and append a unique random number. E.g. profiles.profile_view would be aliased something like ppv27, so you shouldn't ever see a numeric alias unless your table name is somehow numeric (which I think is verboten as well!)