Hello,
I have a table of strings and integer primary keys from which I would like
to retrieve a string at random. The best solution I could think of was to
first do a
SELECT count(id) FROM strings;
and then a
SELECT string FROM strings LIMIT 1 OFFSET ?;
where the parameter is set to an integer in the range [0, count(id)[. This
is not exactly very fast, though. I guess because the second statement
steps through all the rows up to the one that is to be returned.
I can't really use a random primary key to look up a value, because not
every key in the interval [0, count(id)[ is necessarily in use.
And all the constructions I tried that involved random() or a randomly
filled column in an ORDER BY clause yield even worse performance than the
above approach.
Does anybody have a good idea how this could be implemented more
efficiently?
cu,
Thomas
