[dave7]

For online Poker, one of the current database tools runs in to this issue - PokerTracker 4 (PT4).

These tracker databases are usually used to generate a HUD - numerical readouts surrounding each player shown on the table. PT allows for custom HUDs to be saved/exported/shared, and there is a cottage industry building and selling such HUDS. These HUDs can often bundle hundreds of custom stats - basically a subset of SQL queries, a simple example would be "times_raised / opportunities_to_raise WHERE position= 'button'", that sort of thing.

For performance reasons these custom stats are cached, which obviously makes some sense. However, each cached stat creates a new column in the custom_cache table of PT4's current database, a PostgreSQL 9.0 backend. If you play mostly Heads-Up SNG or the 3-handed Spins, it's actually quite easy to go over the (IIRC) 4096 column limit there by purchasing and importing one too many fancy HU HUD packages!

This completely borks PT4, it can no longer open - and players can no longer make money! In my previous work, I've supported many a player and fixed this "too many columns" error numerous times (by deleting enough custom HUDs from their account until the PT4 can start up correctly once more). Funny to see this pop up elsewhere!