MySQL number of items within "in clause"

From the manual:

The number of values in the IN list is only limited by the max_allowed_packet value.

Starting from a certain number, the IN tables are faster.

MySQL has something inside its code that makes building a range over a large number of constant values slower than doing the same in a nested loop.

See this article in my blog for performance details:

• Passing parameters in MySQL: IN list vs. temporary table