用如下语句查询：
select 'blocker(' || lb.sid || ':' || sb.username || ')-sql:' || qb.sql_text blockers, 'waiter (' || lw.sid || ':' || sw.username || ')-sql:' || qw.sql_text waiters from v$lock lb, v$lock lw, v$session sb, v$session sw, v$sql qb, v$sql qw where lb.sid = sb.sid and lw.sid = sw.sid and sb.prev_sql_addr = qb.address and sw.sql_address = qw.address and lb.id1 = lw.id1 and sw.lockwait is not null and sb.lockwait is null and lb.block = 1;
如果有被锁的sql，查询中有结果：
