Warning!
Recently, Jean-François Gagné opened a bug on bug.mysql.com #115517; unfortunately, the bug is now private.
However, the bug looks quite serious. We at Percona have performed several tests and opened the issue PS-9306 to investigate the problem.
In short, what happens is that if you create a large number of tables, like 10000, the mysql daemon will crash at restart.
Currently, we have identified that the following versions are affected:
MySQL 8.0.38
MySQL 8.4.1
MySQL 9.0.0
We have not yet identified the root cause or a workaround. As such, we suggest that all users do not adopt any of the MySQL versions mentioned until a fix is released.
If you want to test it yourself, just install one of the mentioned MySQL versions and run a script like the one used in our issue PS-9306.

About the Author
Marco Tusa
Marco Tusa had his own international practice for the past twenty eight years.
His experience and expertise are in a wide variety of information technology and information management fields, cover research, development, analysis, quality control, project management and team management.
Marco is currently working at Percona as High Availability Practice Manager, previously working at Percona as manager of the Consulting Rapid Response Team on October 2013.
He has being working as employee for the SUN Microsystems as MySQL Professional Service manager for South Europe., and previously in MySQL AB.
He has worked with the Food and Agriculture Organization of the United Nation since 1994, leading the development of the Organization’s hyper textual environment.Team leader for the FAO corporate database support.
For several years he has led the development group in the WAICENT/Faoinfo team. He has assisted in defining the Organization’s guidelines for the dissemination of information from the technology and the management point of view.
He has participated in field missions in order to perform analysis, reviews and evaluation of the status of local projects, providing local support and advice.
He had collaborates with MIT Media Lab (Massachusetts Institute of Technology laboratory) and FAO as Sustainable Information Technology for developing countries Specialist in relation with the FAO’s Special Program for Food Security for Senegal.
Does this issue also affect any version of MariaDB?
No, the specific issue that Percona identified with MySQL versions beyond 8.0.37 does not affect MariaDB. MariaDB, though originally a fork of MySQL, has diverged significantly in its development and architecture. Consequently, bugs and issues in MySQL do not necessarily apply to MariaDB and vice versa.
Jan, we have not tested mariaDB.
At the moment we are focused on the resolution for MySQL.
However if you test it please let us know your findings
Thanks
thanks!
What will you be doing with 10,000 tables in a single database?
This news isn’t fair to MySQL, as people using even less than 1,000 tables on seeing this headline will have a bad feeling about MySQL.
Well in a shared hosting situation, this becomes a DOS vector. Control panel let’s you make a database and then you can make as many tables as you want.
Not a single database but the whole MySQL server
Not fair? Users of any size of MySQL installation need to be concerned if the issue is hidden, as it is worrying behaviour when leadership decides to make a security issue a private affair.
Who on the earth needs 10 thousand tables in a single database?
I was wondering the same.
you’d be surprised how many people actually have a scenario like that or even more
I suppose don’t update if you use that many tables? But for the rest of us it should be ok I think. In my agonist 30 years I’m yet to come across a database with that many tables…
Wow, 30 years. I have a database like that and actually I am not a dB administrator, just a Python developer….
This is a ridiculous way of framing the issue. Telling people not to upgrade past a particular version is irresponsible. What about security vulnerability patches, what about when this is fixed, what about the majority of people this doesn’t even apply to.
This headline and article is pure clickbait and harmful.
Totally agree with you! There is no good reason in this article not to upgrade, unless you fall into the maybe 0.0000001% that has too many tables.
I also think it’s clickbait and just to get publicity.
Better to use msriadb than MySQL crap though
So it triggers with 10k table creation, why should one with 30 tables worry if it doesn’t crash right after upgrade?
Why is this even a blog post..
Checked my Ubuntu 24.04 server and it’s got 8.0.37, with Ubuntu customizations. It’s possible that Canonical is aware of the bug and holding back the update.
Thanks for the post. I’m curious if temp tables are included in this ceiling?
Good to know. Thanks and keep the info following
Its not a bug…… It is karma. For having a borderline insane database schema. Please don’t invest a lot of time this. Instead, focus on performance, security and features that are useful to 99.9999999999 of the users. This whole bug report strikes me as an attempt to see how much MySQL can take before dying. But I have serious doubts that the payload used represents a real world use case. If it is, I am not sorry. This is a them problem. What is next? I cannot create 1 million tables?
I do have some things I don’t like about MySQL but this is not one of them to be honoust.
Not sure if was same issue or not back in 2022 I have same issue with maria db 10.7 lucky I had a backup I didn’t lose any data
Thank you for the valuable information.
We see a similar behavior both in 8.0.38 and 8.4.1 in setup with thousands of databases each with dozen of tables. I’m guessing our setup is not uncommon for sass companies with multitenancy where each client has own database.
Does it also affect the jammy-security 8.0.39?
Is Percona MySQL Server 8.0.37-29 a stable version?