Labels:text | map | diagram | plan | rectangle | screenshot OCR: SQL Query A (update row A) SQL Query B (update row B) SMP SME SMP SMP DBMS DBMS DBMS DBMS Instance 1 Instance 2 Instance 3 Instance 4 Cache Cache Black X Cache Biock X Cashe Row A Locker PINA Row E ROW B Distributed Lock Manager Release (write) Acquire (read) · DLM only needed for block locking Block X Block X Row A still locked when another AP wants the block - Row A still locked · DLM not needed if Query B was in · want row B Instance 1 Block X Shared Disk Row A Row R FIGURE 1. Shared-disk configurations and distributed lock managers.
