I im trying to figure out a simple thing:
how to random select
1 row in a large repetitive
set such that each row had an equal
chance of selection?
For example, a table of products with each product having multiple entries, I just want to select 1 random. But the 'chance'
of that one should not be more than others due to its repetition.
One solution is to get unique list (with GROUP BY
) and get RANDOM
from this subquery. But for a large dataset, thats not an optimal solution, whcihc is what I need help here.
Thanks.
Aucun commentaire:
Enregistrer un commentaire