2.2.1 Architecture overview Figure 2-3 illustrates the processes and memory architecture within DB2 UDB and their relationships to one another. We discuss the memory components in the next section. Local and remote clients are linked to the DB2 UDB client library. In a Siebel implementation, most connections to DB2 UDB are through the various Siebel servers via interactive Application Object Manager (OM) sessions. TCP/IP and APPC are included in the supported communications protocols. Deadlock detector Deadlock detector Deadlock detector Deadlock detector Shared memory and semaphores, TCPIP, Named pipes, NetBIOS, SNA, IPX/SPX Shared memory and semaphores, TCPIP, Named pipes, NetBIOS, SNA, IPX/SPX UDB client library UDB client library Log buffer Log buffer Coordinator Coordinator agent agent Subagents Subagents Coordinator Coordinator agent agent Subagents Subagents Async I/O Async I/O prefetch requests prefetch requests Common prefetch Common prefetch request queue request queue Victim Victim notifications notifications Buffer Buffer Pools