Hello Ilya, Thank you for that suggestion. On a traditional database I know that approach does not scale well, since a random number is first assigned to all rows (it scales linearly with the number of rows if I am not mistaken). Do you think this would be different for Ignite?
Kind regards, Stéphane Thibaud 2019年5月20日(月) 15:53 Ilya Kasnacheev <[email protected]>: > Hello! > > You can have a random indexed field in your table and do queries like > SELECT * FROM table WHERE rand_field < RAND() LIMIT 1; to sample random > item. > > Regards, > -- > Ilya Kasnacheev > > > пн, 20 мая 2019 г. в 04:50, Stéphane Thibaud <[email protected]>: > >> As a small addition: it would really help if Ignite had a hashing >> function for this, but I only see AES encryption. >> >> >> Kind regards, >> >> Stéphane Thibaud >> >> 2019年5月19日(日) 20:59 Stéphane Thibaud <[email protected]>: >> >>> Hello Ignite users, >>> >>> I am considering to sample randomly on large amounts of data, but I was >>> wondering what would be the most efficient way for this. Right now, I think >>> I might need cluster-based randomness using a MOD function as described >>> here: https://www.alandix.com/academic/topics/random/sampling-SQL.html >>> >>> I currently have a UUID column (uuid4), which I think can be used for >>> it, but I might need some bit manipulation to get the non-random parts out >>> of the UUID. >>> Do you think this is indeed the most straightforward way to do it? >>> >>> >>> Kind regards, >>> >>> Stéphane Thibaud >>> >>
