When paging through data that comes from a DB, you need to know how many pages there will be to render the page jump controls.

Currently I do that by running the query twice, once wrapped in a `count()` to determine the total results, and a second time with a limit applied to get back just the results I need for the current page.

This seems inefficient. Is there a better way to determine how many results would have been returned before `LIMIT` was applied?

I am using PHP and Postgres.