Epoch vs. Date and time in mysql

mysql

Solution

You want the unix epoch. I've done many extremely massive MySQL databases, one of which is a data tracking application that logs millions of records every day for some users.

The reasons `epoch` is better than `datetime`:

- `int` is only 4 bytes versus 8 for `datetime` - better for storage/memory and ultimately indexing/performance. When you're dealing with millions of rows, it really matters

- Most server-side languages need to convert from the string format to an int format anyway, before it can reformat the data

- No dependency on timezones - with `datetime` you need convert strings that are not stored with timezone ident but with the epoch you only need to know the timezone converting to

Problem

I have simple question. Which format of time is better for storing in mysql, epoch or standard date-time (human readable format). I want to know what format will be better later in table which stores millions of rows, regarding speed of select statements.

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