Memory structure

The total memory size occupied by a node in OceanBase Database is a proportion of the server's total memory (or it can be configured as an absolute value). A portion of this memory is reserved for the node's own system operations, while the remaining part is allocated to the tenants created on that node. Each tenant is equivalent to an instance in a traditional database. Except for the sys tenant, all user tenants have the same memory module composition. The sys tenant does not have a corresponding Meta tenant; its memory is directly divided into a MemStore for loading incremental data and a KVCache. For other user tenants, there is a corresponding Meta tenant. Therefore, the memory of a user tenant is divided into the tenant's own memory and the memory of its corresponding Meta tenant. Both the tenant's own memory and the corresponding Meta tenant memory are further divided into a MemStore for loading incremental data and a KVCache.