In this section, we will look at the limitations of the data dictionary.
As we saw in the previous sections, the data dictionary of previous versions of MySQL 8.0 had many performance problems because it was all managed from files instead of tables, as Oracle has built-in MySQL 8.0.
One limitation is the need to create manual database directories in the data directory (for example, with mkdir Linux). This is not supported by MySQL. Manually created database directories are not recognized by the MySQL server.
Another limitation is that DDL type operations take longer because of the need to write to storage, the cancellation of logs, and restoring logs instead of .frm.
