- MyISAM permits data and index files to grow up to 256 TiB by default, but this limit can be changed up to the maximum permissible size of 65,536 TiB (256^7 − 1 bytes).
- The maximum tablespace size depends on the InnoDB page size: 64 TiB for 16 KiB pages.
(The maximum tablespace size is also the maximum size for a [InnoDB] table.)
Those questions were raised while discussing with a colleague doing Professional Services and Consulting on MySQL. He was reporting hearing too often unjustified statements like "MySQL surely cannot store that much data" for some big amount of "that much". I told him that I would share some numbers on the big deployments I know about. Here they are with some things to consider when managing such large deployments.