Hi,

When upgrade to > Matomo database will be upgraded from version 3.14.1 to the new version 4.0.5.

I've seen an error in error log [mariadb]

2020-12-15 2:31:19 344 [ERROR] InnoDB: Cannot add field custom_var_k4 in table piwik.piwik_log_visit because after adding it, the row size is 8671 which is greater than maximum allowed size (8126 bytes) for a record on index leaf page.

It is look like no problem with any visit record or reporting. core:update also successfully finished.

I'am not database expert but also I run following command for check db

mariadb-check piwik -c

It's show all table OK

MariaDB [(none)]> SELECT VERSION();
+---------------------------+
| VERSION()                 |
+---------------------------+
| 10.3.27-MariaDB-0+deb10u1 |
+---------------------------+

My version is not affected following bug.

https://jira.mariadb.org/browse/MDEV-19292

I wanted to avoid problems in the future and to share information if anyone is affected.

This my test environment I can share more information for future analysis.

Thanks in advance for your support.