Transactional data dictionary

Up until the previous version, the MySQL data dictionary was stored in different metadata files and non-transactional tables, but from this version, it will have a transactional data dictionary to store the information about the database. No more .frm, .trg, or .par files. All information will be stored in the database, which removes the cost of performing heavy file operations. There were numerous issues with filesystem metadata storage like the vulnerability of the filesystem, exorbitant file operations, difficult to handle crash recovery failures, or replication; it was also difficult to add new feature-related metadata. Now this upgrade has made it simple by storing information in a centralized manner, and will have improved performance as this data dictionary object can be cached in memory, similar to other database objects.

This data dictionary will have data that is needed for SQL query execution such as catalog information, character sets, collations, column types, indexes, database information, tables, store procedures, functions and triggers, and so on.