OceanBase Database is designed based on a multi-tenant architecture, in which a process handles requests from multiple tenants. The tenant memory resources are divided into three types: the memory for the SYS500 tenant (ID = 500), the memory for the SYS tenant (ID = 1), and the memory for business tenants.
The SYS500 tenant is a special virtual tenant. In OceanBase Database, the memory for the SYS500 tenant is the memory shared by physical tenants and the memory consumed by virtual tenants.
The SYS tenant is the first physical tenant of an OceanBase database, also known as an OceanBase cluster. It is automatically created by the system. The SYS tenant manages the internal tables related to the cluster. The memory for the SYS tenant is the memory used by requests for accessing these internal tables.
A business tenant is a physical tenant created by the database administrator (DBA) to run business traffic after an OceanBase cluster is deployed. The memory for a business tenant is the memory used by requests in this tenant.