Intelligent pooling of isolated hierarchical runtimes for cloud scale databases in a multi-tenant environment

One or more non-transitory computer-readable media storing sequences of instructions which, when executed by one or more processors, cause:

• allocating an allocation of operating system resources of a container database management system (CDBMS) to each generic nest of a pool of generic nests, said allocation including a quota of one or more processors, and a quota of memory;
• wherein for a particular generic nest of said pool, an amount of operating system resources in the allocation of operating system resources allocated to said particular generic nest differs from an amount of operating system resources in the allocation of operating system resources allocated to at least one other generic nest in said pool;
• after said allocating, establishing a database session for a particular PDB in the CDBMS, wherein establishing the database session for the particular PDB includes:
• determining a PDB configuration profile for the particular PDB, wherein the PDB configuration profile includes information regarding CPU usage, memory usage, and isolation characteristics of the particular PDB;
• based on the PDB configuration profile determined for the particular PDB, determining a matching generic nest from said pool;
• assigning said matching generic nest to said particular PDB;
• and
• configuring the matching generic nest for said particular PDB, thereby converting the matching generic nest to a PDB nest;
• limiting how much operating system resources may be used by said database session to the respective allocation of operating system resources allocated to said PDB nest.