I was quite nosing around looking for something else, and came across this: |> Until MariaDB 10.2.3, InnoDB and XtraDB used an auto-increment counter that is stored in memory. When the server restarts, the counter is re-initialized to the highest value used in the table, which cancels the effects of any AUTO_INCREMENT = N option in the table statements. ||| Of course. We knew that. What we didn't know, possibly, was the following: || |> From MariaDB 10.2.4, this restriction has been lifted and AUTO_INCREMENT is persistent.| || Note that this isn't the current package version of mariadb-server for Debian 9, it's lagging behind a bit at 10.1.26. However, the days of auto increment issues, at least for MariaDB, may soon be coming to a close. Information from: https://mariadb.com/kb/en/library/auto_increment/ -- Liz Rea Catalyst.Net Limited Level 6, Catalyst House, 150 Willis Street, Wellington. P.O Box 11053, Manners Street, Wellington 6142 04 803 2265 GPG: B149 A443 6B01 7386 C2C7 F481 B6c2 A49D 3726 38B7