Viewing Data Dictionary Tables Using a Debug Build of MySQL

Viewing Data Dictionary Tables Using a Debug Build of MySQL

Data dictionary tables are protected by default but can be accessed by compiling MySQL with debugging support (using the -DWITH_DEBUG=1 CMake option) and specifying the +d,skip_dd_table_access_check debug option and modifier. For information about compiling debug builds, see Section 5.9.1.1, “Compiling MySQL for Debugging”.

Warning

Modifying or writing to data dictionary tables directly is not recommended and may render your MySQL instance inoperable.

After compiling MySQL with debugging support, use this SET statement to make data dictionary tables visible to the mysql client session:

mysql> SET SESSION debug='+d,skip_dd_table_access_check';

Use this query to retrieve a list of data dictionary tables:

mysql> SELECT name, schema_id, hidden, type FROM mysql.tables where schema_id=1 AND hidden='System';

Use SHOW CREATE TABLE to view data dictionary table definitions. For example:

mysql> SHOW CREATE TABLE mysql.catalogs\G