I have a server with 12GB RAM, and max_heap_table_size in my.cnf is set to 6GB. ("max_heap_table_size=6442450944"). I restarted the MySQL server after setting this.
The trouble is, whenever my table gets to just 2GB during inserts I get error "table full". Why is it not letting me add more than 2GB worth of data? (The 2GB figure is what is shown as the size in phpMyAdmin)
A 32 bit MySQL server (or any 32 bit application for that matter) only have 2-3Gb(Depending on the OS, etc.) of virtual memory available, and thus can't address more memory. You need a 64 bit OS, and a 64 bit MySQL server to take advantage of more memory.