Communications Portion of Shared Memory

The database server allocates memory for the IPC communication portion of shared memory if you configure at least one of your connections as an IPC shared-memory connection. The database server performs this allocation when you initialize shared memory. The communications portion contains the message buffers for local client applications that use shared memory to communicate with the database server.

The size of the communications portion of shared memory equals approximately 12 kilobytes multiplied by the expected number of connections needed for shared-memory communications (nettype ipcshm). If nettype ipcshm is not present, the expected number of connections defaults to 50. For information about how a client attaches to the communications portion of shared memory, refer to How a Client Attaches to the Communications Portion.