1 The syntax of the SQL statement is verified. SQL的语法检查 2 The data dictionary is searched to verify table and column definitions. 从数据字典检查表名和字段名 3 The data dictionary is searched to verify security privileges on relevant objects. 从数据字典中检查权限 4 Parse locks are acquired on the relevant objects. 解析相关对象的锁 5 The optimal execution plan is determined. 选在执行计划运行SQL 6 The statement is loaded into the shared SQL area (also known as the library cache) in the shared pool of the system global area (SGA). 执行后SQL语句放在SGA的SQL共享区