【12c新特性】12c中新後臺進程

【12c新特性】12c中新後臺進程，主要包括但不侷限於：  

OFSD	Oracle File Server BG
RMON	rolling migration monitor
IPC0	IPC Service 0
BW36	db writer process 36
BW99	db writer process 99
TMON	Transport Monitor
RTTD	Redo Transport Test Driver
TPZ1	Test Process Z1
TPZ2	Test Process Z2
TPZ3	Test Process Z3
LREG	Listener Registration
AQPC	AQ Process Coord
FENC	IOServer fence monitor
VUBG	Volume Driver Umbilical Background
SCRB	ASM Scrubbing Master

    能夠看到這裏LREG進程開始負責對Listener Registration監聽器的註冊： Service registration enables the listener to determine whether a database service and its service handlers are available. A service handler is a dedicated server process or dispatcher that acts as a connection point to a database. During registration, the LREG process provides the listener with the instance name, database service names, and the type and addresses of service handlers. This information enables the listener to start a service handler when a client request arrives. Figure 16-5 shows two databases, each on a separate host. The database environment is serviced by two listeners, each on a separate host. The LREG process running in each database instance communicates with both listeners to register the database.   截止目前12c的官方文檔中的配圖還有問題， 圖示仍是用PMON註冊監聽。     Reference: E16655_01/E16655_01/server.121/e17633/dist_pro.htm#CHDIBHAD