MySQL本身无任何限制,但是会受到操作系统的最大文件个数限制,另外某些存储引擎,也有自己的一些限制,但是一般上亿是没啥问题的,足够你用了哈。官网手册上的原文如下:
MySQL has no limit on the number of databases. The underlying file system may have a limit on the number of directories.
MySQL has no limit on the number of tables. The underlying file system may have a limit on the number of files that represent tables. Individual storage engines may impose engine-specific constraints. InnoDB permits up to 4 billion tables.
手册地址:
MySQL :: MySQL 5.7 Reference Manual :: C.10.2 Limits on Number of Databases and Tables