What can I do to increase the performance of a Lua program?

Question

I asked a question about Lua perfromance, and on of the responses asked:

Have you studied general tips for keeping Lua performance high? i.e. know tab

Answer 1

Keep tables short, the larger the table the longer the search time. And in the same line iterating over numerically indexed tables (=arrays) is faster than key based tables (thus ipairs is faster than pairs)