If you have seen the following error:

[HY000][50000] General error: "The write format 1 is smaller than the supported format 2 [2.1.210/5]" [50000-210]
The write format 1 is smaller than the supported format 2 [2.1.210/5].

You probably upgraded your H2 dependency from 1.x.y to 2.x.y due to a suggestion from Dependabot, like this one:

dependabot alerts

While I’m glad these alerts exist, there’s little information on how to update your existing H2 database.

Solution

I’ve gone about this by doing the following steps:

  • Create a backup of the v1 H2 database
  • Create a new database v2 H2 database with that backup

Download H2 Lib

The tricky part is that you must use the correct library version for this to work out, but otherwise it’s a straightforward process. Let’s begin by obtaining the H2 jar from Maven Central, we’ll need both v1 and v2:

# Download v1
curl -Lo h2-v1.jar https://search.maven.org/remotecontent\?filepath\=com/h2database/h2/1.4.200/h2-1.4.200.jar

# Download v2
curl -Lo h2-v2.jar https://search.maven.org/remotecontent\?filepath\=com/h2database/h2/2.1.210/h2-2.1.210.jar

Create Backup SQL Script

Please create a backup of your current H2 database at this time, it would be a shame if it got deleted.

The H2 library contains a tool called Script that we will use to generate the backup.sql script:

# For a set of all possible options, run with -help
java -cp h2-v1.jar org.h2.tools.Script -url "jdbc:h2:file:path/to/database/h2.db" -script backup.sql

I’d take a quick peek at the backup.sql file just to make sure the data is there, but otherwise we’re done with this step.

Create new database from SQL Script

Just like with the tool above, there’s a tool to run a script called RunScript that we will use to create a new database from backup.sql:

# For a set of all possible options, run with -help
java -cp h2-v2.jar org.h2.tools.RunScript -url "jdbc:h2:file:path/to/database/h2-v2.db" -script backup.sql

This should create a new H2 database as h2-v2.db. At this point, change your application to use this database, if everything works well, then you can delete the old one and rename the new one.

Enjoy!