We have a WP page running with a Buddypress network, which is highly dynamic. We are trying to identify every possible opportunity to reduce load and storage – and found that quite some tables use BIGINT values. E.g. the user table, and by doing so, all other relational tables which refer to the userid.
We will never ever have 4 billion (!!!!) users which should be the limit of a regular UNSIGNED INT. Therefore I raise the question, whether this could be an VERY easy way to reduce storage and maybe slightly decreasing load on the MySQL server by handling smaller pieces of information while doing queries.
I mean I understand BIGINT can make sense – e.g. for the postmeta and usermeta data, because every uploaded picture etc is treated as a post, and with it are coming a lot of metadata…
Is there any downside in changing all userid fields to INT? I mean, it’s such a simple operation using PHPMyAdmin…
EDIT:
Unsigned INT handles 4 billion, not 4m users (which I had initially written). So whoever thought to support WP with 4b users and thereby doubling space for all userid fields (in posts, usermeta etc), must have gone crazy 😀