How to remove references to performance_schema.user_variables_by_thread in mysql 5.6?

Question

I have a Jira 6.4.7 instance running on MySQL 5.6.44. I'm in the progress of updating the Jira instance to 7.0.5, which still supports MySQL 5.6.

I accidentally hooked up a newer Jira 7.0.5 to the same database, wich inserted performance_schema tables. Jira 7.0.5 probably thought it was running with >= mysql 5.7.

I immediately stopped the Jira 7.0.5 instance, but the references to performance_schema are still there.

When I look at the database with MySQL Workbench, I get this error:

Error Code: 1146 Table 'performance_schema.user_variables_by_thread' doesn't exist

Everything still seems to work with jira 6.4.7, but I can't dump the database anymore to move it somewhere else.

I've tried using the xml export and import from jira, but this copies the error from the database.

I've tried

[mysqld]
performance_schema=OFF

but the error persists.

I couldn't find the performance_schema table in other MySQL databases, because then I could have copied the table.

So how can I fix this? Can anyone provide an SQL statement of how this table should look like? Or how can I find and delete the references to performance_schema in my current MySQL 5.6 database?.

Answer 1

performance_schema.user_variables_by_thread is in MySQL-5.7 but not MySQL-5.6. It cannot be copied as its generated by the server to represent the internal state.

MySQL-5.6 seems to have deprecated Jira support per https://confluence.atlassian.com/adminjiraserver/supported-platforms-938846830.html

MySQL-5.7 reference on user_variables_by_thread

Answer 2

The issue was using MySQLWorkbench 8.0.16 and mysqldump 8.0.19 which are both looking for performance_schema tables in MySQL 5.6, which only exist starting with MySQL 5.7. Updating MySQLWorkbench to 8.0.20 and using mysqldump with the flag --column-statistics=0 made the errors go away.