How do I reset sequence numbers to become consecutive?

Question

I\'ve got a mysql table where each row has its own sequence number in a \"sequence\" column. However, when a row gets deleted, it leaves a gap. So...

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Answer 1

I'd say don't bother. Reassigning sequential values is a relatively expensive operation and if the column value is for ordering purpose only there is no good reason to do that. The only concern you might have is if for example your column is UNSIGNED INT and you suspect that in the lifetime of your application you might have more than 4,294,967,296 rows (including deleted rows) and go out of range, even if that is your concern you can do the reassigning as a one time task 10 years later when that happens.