Glad to know that....could that possibly be mentioned in the random() notes on the core functions? Thought that is (apparently) a C function and not SQL accessible?
Michael D. Black Senior Scientist Advanced Analytics Directorate Advanced GEOINT Solutions Operating Unit Northrop Grumman Information Systems ________________________________ From: sqlite-users-boun...@sqlite.org [sqlite-users-boun...@sqlite.org] on behalf of Simon Davies [simon.james.dav...@gmail.com] Sent: Thursday, March 08, 2012 8:33 AM To: General Discussion of SQLite Database Subject: EXT :Re: [sqlite] Efficient random sampling in a large table using builtin functions. On 8 March 2012 14:20, Black, Michael (IS) <michael.bla...@ngc.com> wrote: > You don't say what language you are working in. IN C++ I would just declare > a "set" and put random row numbers in it until I had enough. Then use that > set to build the SQL. > > SQLite's random() doesn't have a seed function so you don't really get very > random numbers from run-to-run and have no good way of controlling it that I > can find in the docs. You want to use your language's random function if you > want anything close to real randomness. http://www.sqlite.org/c3ref/randomness.html claims high-quality PRNG > > Hopefully your language has a similar data structure you can use. > > > Michael D. Black > > Senior Scientist > > Advanced Analytics Directorate > > Advanced GEOINT Solutions Operating Unit > > Northrop Grumman Information Systems > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
