客户有个问题，同义词突然失效了，第一反应是Oracle Page包失效会在下一次调用中自动编译？
测试一下同义词！
结论是可以自动编译，那么问题在于什么原因导致查询同义词没有自动编译成功！ 这个可以根据具体报错排查
SQL> select count(*) from syn_a; COUNT(*) ---------- 37784 SQL> alter table a move; select object_name,object_type,status from user_objects; OBJECT_NAME OBJECT_TYPE STATUS -------------------- ------------------- ------- SYN_A SYNONYM VALID A TABLE VALID A_VIEW VIEW VALID SQL> drop table a; SQL> select object_name,object_type,status from user_objects; OBJECT_NAME OBJECT_TYPE STATUS -------------------- ------------------- ------- SYN_A SYNONYM INVALID A_VIEW VIEW INVALID SQL> create table a as select * from sys.dba_objects; SQL> select count(*) from a_view; COUNT(*) ---------- 37784 SQL> select object_name,object_type,status from user_objects; OBJECT_NAME OBJECT_TYPE STATUS -------------------- ------------------- ------- A TABLE VALID SYN_A SYNONYM INVALID A_VIEW VIEW VALID SQL> select count(*) from syn_a; COUNT(*) ---------- 37784 SQL> select object_name,object_type,status from user_objects; OBJECT_NAME OBJECT_TYPE STATUS -------------------- ------------------- ------- A TABLE VALID SYN_A SYNONYM VALID A_VIEW VIEW VALID