The orientdb documentation doesn't say anything about limitations regarding the number of classes. In practise it seems a large number of classes is limiting functionality.
I have a database with the Buildingsmart IFC classes as it's schema. This means I have a lot of classes. Every time a connection to the db is made, the server sends the complete list of classes (clusters). As a result, opening my database is taking too much time.
Is there a way to tell orientdb not to sent the list? I already know the internal db class structure, so I don't really have need for the list.
The maximum number of classes supported by OrientDB is a function of number of clusters in the database. Refer the clustering section.
Starting from v2.2, OrientDB automatically may create multiple clusters per each Class to improve the performance of parallelism. The number of clusters created per class is equal to the number of CPU cores available on the server. You can also have more clusters per class. The limit on the number of clusters in a database is 32,767 (or, 215 - 1)
For CPU of 4 core, therefore, assuming each class has default number of clusters, the total class count in the database would be ~8100.