[debian-mysql] Bug#990763:

[Daniel Black]

Hi,

MDEV-25394 is dissimilar. It is in InnoDB while this appears to be in
the optimizer code.

A new 10.3.31 is coming soon
https://salsa.debian.org/mariadb-team/mariadb-10.3/-/pipelines/273217

The optimizer related fixes in the two version since 10.3.29 are:
https://jira.mariadb.org/issues/?jql=fixVersion%20%20in%20(10.3.30%2C%2010.3.31)%20and%20component%20%3D%20Optimizer

Looking at these bugs I can't see anything that looks particularly equivalent.

So in summary, we do need more information to resolve this. Ideally
this should be a new MDEV project bug on https://jira.mariadb.org/.

The information that would be most useful is:
* the query that caused this. This should of been in the log
* `SHOW CREATE TABLE {tablename}` for the table is the query.
* EXPLAIN EXTENDED {query}; SHOW WARNINGS

The stack trace shows this is occurring as a prepared statement. If
you are willing to risk the availability of the server running this as
a non-prepared statement straight from the mariadb command line that
would be useful as a test point.

If the core file is still available/reproducible the following
additional resolution of the stack traces that will aid MariaDB staff.

 cat >>/etc/apt/sources.list.d/debug.list <<'EOT'
deb http://deb.debian.org/debian-debug buster-debug main contrib non-free
EOT

 apt-get install -y gdb mariadb-server-core-10.3-dbg

gdb /usr/sbin/mysqld core

thread apply all bt full

The dbg symbols and gdb resolution can be on a different server or
even in a container that can access the core.

If this contains confidential information like tablenames (its
unlikely to contain table contents) of your client you can use
https://mariadb.com/kb/en/meta/mariadb-ftp-server/ to make this only
available to MariaDB people for the purpose of debugging this issue.