Question

I can set the primary key as a timestamp accurate to seconds. But it works as intended only when new rows are inserted a minimum of 1 second apart. I can increase the resolution to microseconds, but I wonder if it’s overkill and slow stuff down.

I want timestamps since they are easy to sort on time but I don’t care about prescription greater than a second.

What is a good way to generate them?

Answer 1

It all depends on what queries you expect to process.

You can actually use both TIMESTAMP and some surrogate primary key; the latter would be auto_incremented, as usual, and the former may be indexed over as well for some sorting queries:

CREATE TABLE sometable (
  sometable_id INT NOT NULL AUTO_INCREMENT,
  ...
  ts TIMESTAMP,
  PRIMARY KEY (sometable_id),
  KEY (ts)
);

… or you can drop the surrogate key altogether and go without PRIMARY KEY -w With a single INDEX over TIMESTAMP column (remember, INDEX != UNIQUE).

I would use the first approach, though; it’s more flexible and extensible.