Tables gone after migration when separate events schema added to store configuration

[tjdaniel]

I had a "documents only" store before:

	public IDocumentStore DocumentStore { get; } = Marten.DocumentStore.For(_ =>
		{
			_.Connection(connectionString);

			_.AutoCreateSchemaObjects = isTestEnvironment ? AutoCreate.All : AutoCreate.None;
			_.DatabaseSchemaName = "my_store";

			_.UseNewtonsoftForSerialization(configure: options =>
			{
				options.DefaultValueHandling = DefaultValueHandling.Ignore;
			});

			_.Schema.Include<MyRegistry>();
		});

I added a separate events schema and diffed the schema with the Weasel methods:

	public IDocumentStore DocumentStore { get; } = Marten.DocumentStore.For(_ =>
		{
			_.Connection(connectionString);

			_.AutoCreateSchemaObjects = isTestEnvironment ? AutoCreate.All : AutoCreate.None;
			_.DatabaseSchemaName = "my_store";

			// Configure Event Store
			_.Events.DatabaseSchemaName = "my_events";

			_.UseNewtonsoftForSerialization(configure: options =>
			{
				options.DefaultValueHandling = DefaultValueHandling.Ignore;
			});

			_.Schema.Include<MyRegistry>();

			_.Events.AddEventType<PaymentAdviceImported>();
		});

...
	var migration = await documentStore.Storage.CreateMigrationAsync();
	var differences = migration.Deltas.Where(d => d.Difference != SchemaPatchDifference.None).ToList();

It recognizes the missing schema at the beginning, but the migration draws all current state from a single big read command where it tries to query all objects from both schemas. In my case there were 178 objects in the list of the to-be-compared objects. It also to checks objects from the new schema which obviously are not there, and the reader throws an exception (schema not found) and finishes work. The rest of the list still runs through and all remaining objects (even existing) are marked as non-existing. This blows all tables away that happen to be "after" any new schema objects in the comparison list (around 3/4 of my tables).

So as a workaround I create the schema before, but this is non-obvious.

This raises the question, why don't group the detection by schema?

[jeremydmiller]

@tjdaniel What you did isn't something we ever accounted for. You could have just written a manual script to move things. In this case Marten no longer even knows about the previous schema, and why would it?

In the future, could you please use Discord or even Discussions for questions and not Issues?