getting error message doing backup from mariadb 5.5.64

[nugrahadi]

because I'm not sure whether to write it as an issue or not, so I'll write it here first.

I have a problem backing up a database server, it has this error log

Backup failed: mariadb-dump: Couldn't execute 'select column_name, extra, generation_expression, data_type from information_schema.columns where table_schema=database() and table_name='access_keys' order by ordinal_position': Unknown column 'generation_expression' in 'field list' (1054)

already tried using --column-statistics=0 and --compact but the error still exist

database server version is mariadb-5.5.64. any suggestion?

[David-Crty]

Hey @nugrahadi 👋

That error isn’t really a Databasement bug — it’s a client/server version mismatch.

What’s actually happening

Databasement ships a recent mariadb-dump binary (MariaDB 10.x / 11.x) in its Docker image. When that client connects to a server, it runs internal metadata queries against information_schema.columns, including the generation_expression column. That column was introduced in MariaDB 10.2 / MySQL 5.7 to support generated/computed columns.

Your source server is MariaDB 5.5.64, where generation_expression simply does not exist — hence:

Unknown column generation_expression in field list (1054)

Flags like --column-statistics=0 or --compact are for unrelated features (histograms and output formatting), so they don’t help here. There is no mariadb-dump flag that disables that metadata query — it runs unconditionally before any rows are dumped.

What I’d recommend

The right fix is to upgrade the source server. MariaDB 5.5 has been End-of-Life since April 2020 — no more security patches, no more bug fixes, and as you can see it’s no longer compatible with current client tooling. Even moving to MariaDB 10.6 (a current LTS) would solve this and a lot of other latent issues.

If upgrading really isn’t possible right now, your only realistic options are:

1. Dump manually from a host that still has a 5.5-era mysqldump client, then store the file yourself. Databasement can’t orchestrate that because it doesn’t ship a legacy client.
2. Use replication to a newer MariaDB instance and point Databasement at the replica.

I’m going to leave Databasement’s mariadb-dump version as-is — supporting an EOL-since-2020 server inside the image isn’t really feasible to maintain, and the security implications of running a 5.5 server in 2026 are a much bigger problem than the backup tooling.

Hope that clarifies it 🙏