SQLite Forum

What does, if many threads and/or processes need to write the database at the same instant, mean?
500K visits a day.  To allow for a working day and mixed timezones, assume a 12 hour day with equal distribution.  That's 42,000 visits an hour, 700 visits a minute, 12 visits a second, perhaps peak at 18 visits in a second.

You describe each visit being one or two very simple SQL commands.  There's nothing in SQLite which would fail to deal with that, **assuming solid state storage**.  You're more likely to encounter problems with your web backend (LAMP ?) or, if your web pages are huge, bandwidth.

Assuming your data is valuable, I remind you to figure out your backup strategy procedure right at the start.