What you would like to accomplish

In a schema-separated multi-tenant system [1], if FGAC is enforced to tables, the max tables per database is only 100, not 5000, because of this "roles per database" limit. Our customers request this limitation to be increased to 5000.

In this multi-tenant system, we recently released fine-grained access control (FGAC) that allows access permissions to be provided at the table level. However, while we allow 5,000 tables per database, we only allow 100 roles per database, which limits the number of FGAC-enforced tables. This is a significant disparity. This severely limits the number of tenants (customers) we can include in a single database to 100, despite FGAC being ideally suited for multi-tenant systems. This limitation forces us to create multiple databases in most use cases, which increases administrative overhead for our customers.

How this might work

Increase the limit to 5000 or 10000.

If applicable, reasons why alternative solutions are not sufficient

• A instance-separated system, the cost would be extremely high with 1 node each. 0.1 node each will remove the SLA and it may still be expensive.
• A database-separated system, they need 100 tenants/node, which may be still expensive.

Comparison is well described here.

• [1] https://cloud.google.com/solutions/implementing-multi-tenancy-cloud-spanner#schema
• [2] https://cloud.google.com/spanner/docs/schema-and-data-model#multitenancy
• [3] https://medium.com/google-cloud/implementing-multi-tenancy-in-cloud-spanner-3afe19605d8e