Question

I have a fairly large table with about 250k rows. It has an auto incremented ID column that is really sort of useless. I can’t just get rid of the column without rewriting too much of the app, but the ID is never used as a foreign key or anything else (except simply as an identifier when you want to delete a row, I guess).

The majority of the data gets deleted and rewritten at least a few times a day (don’t ask! it’s not important, though I realize it’s poor design!), though the total count of the rows stays fairly uniform. What this means is that each day to AI # increases by a quarter million or so.

My question is this: in several years’ time, the ID column will get too large for the INT value. Is there a way to “reset” the ID, like an OPTIMIZE or something, or should I just plan on doing a SELECT INTO a temp table and truncating the original table, resetting the ID to 0?

Thanks

Answer 1

If you have the id as integer you can have 2^32 / 2 (2.147.483.647) rows, if is unsigned integer duplicate to 4.294.967.295, no worry 250.000 in nothing, if you want more, use unsigned bigint (18.446.744.073.709.551.615) 😛

For reset the auto_numeric position:

ALTER TABLE table AUTO_INCREMENT = 1