Process and Runtime Limits

Item Type of Limit Limit Value
Instances per database Maximum number of cluster database instances per database Operating system-dependent
Locks Row-level Unlimited
Locks Distributed Lock Manager Operating system dependent
SGA size Maximum value Operating system-dependent; typically 2 to 4 GB for 32-bit operating systems, and > 4 GB for 64-bit operating systems
Advanced Queuing Processes Maximum per instance 10
Job Queue Processes Maximum per instance 1000
I/O Slave Processes Maximum per background process (DBWR, LGWR, etc.) 15
I/O Slave Processes Maximum per Backup session 15
Sessions Maximum per instance 32 KB; limited by the PROCESSES and SESSIONS initialization parameters
Global Cache Service Processes Maximum per instance 10
Shared Servers Maximum per instance Unlimited within constraints set by the PROCESSES and SESSIONS initialization parameters, for instance
Dispatchers Maximum per instance Unlimited within constraints set by PROCESSES and SESSIONS initialization parameters, for instance
Parallel Execution Slaves Maximum per instance Unlimited within constraints set by PROCESSES and SESSIONS initialization parameters, for instance
Backup Sessions Maximum per instance Unlimited within constraints set by PROCESSES and SESSIONS initialization parameters, for instance