$ oerr ora 12637
12637, 00000, "Packet receive failed"
// *Cause: A process was unable to receive a packet from another process.
// Possible causes are:
// 1. The other process was terminated.
// 2. The machine on which the other process is running went down.
// 3. Some other communications error occurred.
// *Action: If the cause is not obvious, contact Oracle Customer Support.
--//https://support.oracle.com/knowledge/Oracle%20Database%20Products/2662778_1.html
My Oracle Support Banner
Oracle 19c Client returns ORA-12637 when connecting to a 19c Database. Does not reproduce when using an older client
version. (Doc ID 2662778.1)
Symptoms
Sqlplus using a Version 19c client yield ORA-12637 when trying to connect to a 19c database.
...
Changes
New Feature added to 19c. Client will trigger the server to test for OOB availability at connect time. If it fails the
error is reported.
--//翻译：新功能添加到19c。客户端将触发服务器在连接时测试OOB的可用性。如果失败，将报告错误。
--//注解:我的理解即使报ora-12637错误,还是可以使用的,当然我没有测试。
--//http://blog.chinaunix.net/uid-20687159-id-5858993.html
数据异常或中断是 Oracle NET 中的一个功能，它允许在事务完成之前将其中断。它将客户端和服务器返回到可以继续的状态。诸如
Ctrl-c 之类的中断可以作为正常数据流(带内)的一部分发送，也可以作为单独的异步消息(带外)发送。带外中断要快得多并且会中断数
据流。
如果底层协议支持发送紧急数据，则默认启用带外中断 (OOB) 。
如果参数 DISABLE_OOB设置为 OFF，则它使 Oracle Net 能够使用底层协议提供的紧急数据发送和接收"中断"消息。
SYS@192.168.100.237:1521/orcldg> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
222 31147 33907 DEDICATED 120029 101 9489 alter system kill session '222,31147' immediate;
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
select count(*) from dba_source,all_objects
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
--//按ctrl+C出现如上提示,没有任何影响,可以继续执行任何语句的执行.
SYS@192.168.100.237:1521/orcldg> select sysdate from dual ;
SYSDATE
-------------------
2023-03-27 09:22:41
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
--//在192.168.100.237上执行:
$ kill -URG 120029
--//你可以发现sql语句没有出现中断,而是继续执行.也就是忽略URG的中断信号。
3.修改服务端sqlnet.ora,注解disable_oob = ON:
--//缺省disable_oob = off.
--//session 1:
SYS@192.168.100.237:1521/orcldg> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
364 52618 34014 DEDICATED 125668 45 4622 alter system kill session '364,52618' immediate;
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
select count(*) from dba_source,all_objects
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
--//按ctrl+C出现如上提示,没有任何影响,可以继续执行任何语句的执行.
SYS@192.168.100.237:1521/orcldg> select sysdate from dual ;
SYSDATE
-------------------
2023-03-27 09:28:53
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
--//session 1:
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
select count(*) from dba_source,all_objects
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
--//中断sql语句运行,说明可以接收URG中断.
SYS@192.168.100.237:1521/orcldg> select sysdate from dual ;
SYSDATE
-------------------
2023-03-27 09:32:59
--//可以缺省情况下(disable_oob = off)下,对应进程可以接收URG信号.
4.ALTER SYSTEM CANCEL SQL测试,disable_oob = ON:
--//突然想起12c支持运行时取消正在运行的sql语句。补充测试看看。
--//修改服务端sqlnet.ora:
--//加入disable_oob = ON
--//session 1:
SYS@192.168.100.237:1521/orcldg> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
54 16475 46350 DEDICATED 95789 121 1743 alter system kill session '54,16475' immediate;
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
select count(*) from dba_source,all_objects
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation
--//session 2:
--//ALTER SYSTEM CANCEL SQL 'SID, SERIAL;
--//ALTER SYSTEM CANCEL SQL 'SID, SERIAL, SQL_ID';
--//ALTER SYSTEM CANCEL SQL 'SID, SERIAL, @INST_ID, SQL_ID';
--//说明：ALTER SYSTEM CANCEL SQL支持3种格式。选择第1种格式测试看看。
SYS@192.168.100.237:1521/orcldg> alter system cancel sql '54,16475' ;
System altered.
--//OK.没有问题.我估计使用的不是URG信息.
SYS@192.168.100.237:1521/orcldg> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
377 18810 4251 DEDICATED 98463 105 9553 alter system kill session '377,18810' immediate;
SYS@192.168.100.237:1521/orcldg> select count(*) from dba_source,all_objects;
select count(*) from dba_source,all_objects
*
ERROR at line 1:
ORA-01013: user requested cancel of current operation