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Fetch random results form MySQL

If you read the MySQL manual you might have seen the ORDER BY RAND() to randomize the the rows and using the LIMIT 1 to just take one of the rows.

 SELECT name

 FROM random

 ORDER BY RAND()

 LIMIT 1;


The reason that ordering by RAND() can be slow is that you're forcing the database to actually sort the whole table before returning anything. Just reducing the load to a single table scan is much faster (albeit still somewhat slow).

 SELECT name

 FROM random AS r1 JOIN

 (SELECT CEIL(RAND() *

 (SELECT MAX(id)

 FROM random)) AS id)

 AS r2

 WHERE r1.id >= r2.id

 ORDER BY r1.id ASC

 LIMIT 1
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