A.4 Process and Runtime Limits

This table describes limit types and limit values for process and runtime items.

Item	Type of Limit	Limit Value
Advanced Queuing Processes	Maximum per instance	10
Backup Sessions	Maximum per instance	Limited by the PROCESSES and SESSIONS initialization parameters, for instance
Dispatchers	Maximum per instance	Limited by the PROCESSES and SESSIONS initialization parameters, for instance
Global Cache Service Processes	Maximum per instance	10
Instances per database	Maximum number of cluster database instances per database	Operating system-dependent
I/O Worker Processes	Maximum per background process (DBWR, LGWR, and so on)	15
I/O Worker Processes	Maximum per Backup session	15
Job Queue Processes	Maximum per instance	1000
Locks	Distributed Lock Manager	Operating system dependent
Locks	Row-level	Not defined
Parallel Execution Workers	Maximum per instance	Limited by the PROCESSES and SESSIONS initialization parameters, for instance
Services	Maximum per instance	8200
Sessions	Maximum per instance	216; limited by the PROCESSES and SESSIONS initialization parameters. 216 is 65536.
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
Shared Servers	Maximum per instance	Limited by the PROCESSES and SESSIONS initialization parameters, for instance