The number of concurrent Extract and Replicat process groups that can run on a system depends on how much system memory is available. Each Extract and classic Replicat process needs approximately 25-55 MB of memory or more, depending on the size of the transactions and the number of concurrent transactions. The Oracle GoldenGate command interface fully supports up to 5,000 concurrent Extract and Replicat groups (combined) per instance of Oracle GoldenGate. At the supported level, all groups can be controlled and viewed in full with commands such as the INFO and STATUS commands.

Beyond the supported level, group information is not displayed and errors may occur. Oracle GoldenGate recommends keeping the number of Extract and Replicat groups (combined) at a more manageable level, such as 100 or below, in order to manage the environment effectively. The maximum number of groups is controlled by the MAXGROUPS parameter, which has a default value of 1000.

For Windows Server environments, the number of process groups that can be run are tightly coupled to the ‘non-interactive’ Windows desktop heap memory settings. The default settings for Windows desktop heap may be enough to run very small numbers of process groups, but as you approach larger amounts of process groups, more than 60 or so, you will either need to adjust the ‘non-interactive’ value of the SharedSection field in the registry, based on this information from Microsoft (Windows desktop heap memory), or increase the number of Oracle GoldenGate homes and spread the total number of desired process groups across these homes.