Hello,
I have a virtual table that implements query perceptual hashing data[1]. Now I'm thinking about converting the virtual table implementation in a collation on a normal sqlite3 table, but collation requieres that '=','<' and '>' be well defined by obeying the rules cited on create_collation() page[2]. Sometimes, rule 2 may not be true, but I always query for '=', never need sort query output and result is unique. If I calculate the perceptual hash of an input, I want to get the closer (minimal distance) hash in the table calculating equal . Can I use a collation in this case? [1] Perceptual Hashing: Hash function that similar input data has equal or similar hash. [2] http://www.sqlite.org/c3ref/create_collation.html 1.If A==B then B==A. 2.If A==B and B==C then A==C. 3.If A<B THEN B>A. 4.If A<B and B<C then A<C. --- --- Eduardo Morras <emorrasg at yahoo.es>
