复制的方式 半保留复制(semi= conservative replication 复制的高保真性( high fidelity) 双向复制( bidirectional replication ●半不连续复制(semi- discontinuous replication)⚫复制的方式 ——半保留复制(semi-conservative replication) ⚫复制的高保真性(high fidelity) ⚫双向复制(bidirectional replication) ⚫半不连续复制(semi-discontinuous replication)