先来段英文的,2层和4层存放结构:
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In the two-tier deployment, the Java based rich client, the enterprise-tier server and the supporting software run on the users’ workstations. Database, volumes and other resource-tier components run on separate systems.
In the four-tier deployment, only the Java based rich client runs on the users’ workstations. The enterprise tier, database, volumes and other resource-tier components run on separate systems.