在工作中很多新手会遇到这种问题，就是操作系统显示有个PID占用的CPU很高，导致整个系统运行很慢，
同时又不敢轻易的对这个PID进行KILL操作，很是头疼。
今天就和大家分享下，怎么通过操作系统的PID查找相应的数据库session和语句。
第一步：通过可以通过操作系统的PID查找数据库的v$process进程，语句如下：
select * from v$process where SPID='&PID'
第二步：查找相应的SESSION信息
SELECT SID,SERIAL#, USERNAME,MACHINE
FROM v$session b
WHERE b.paddr = (SELECT addr
FROM v$process c
WHERE c.spid = '&pid')；
第三步：通过第二步查找出来的SID，可以进一步查找正在执行的SQL语句
select b.sql_text
from v$session a,v$sqlarea b
where a.sql_hash_value=b.hash_value and a.sid=‘&SID';
另外可以通过下面这条语句查找后台进程的名字
SELECT s.SID SID, p.spid threadid, p.program processname, bg.NAME NAME
FROM v$process p, v$session s, v$bgprocess bg
WHERE p.addr = s.paddr
AND p.addr = bg.paddr
AND bg.paddr '00';
经过一番查询如果发现当前的session有问题，具体怎么判断是否有问题，会继续介绍。
操作系统的杀进程的操作很简单，语句如下kill -9 pid
附：V$PROCESS和V$SESSION的各字段说明
| Column | Datatype | Description |
| ADDR | RAW(4 | 8) | Address of process state object |
| PID | NUMBER | Oracle process identifier |
| SPID | VARCHAR2(12) | Operating system process identifier |
| USERNAME | VARCHAR2(15) | Operating system process username. Any two-task user coming across the network has "-T" appended to the username. |
| SERIAL# | NUMBER | Process serial number |
| TERMINAL | VARCHAR2(30) | Operating system terminal identifier |
| PROGRAM | VARCHAR2(48) | Program in progress |
| TRACEID | VARCHAR2(255) | Trace file identifier |
| BACKGROUND | VARCHAR2(1) | 1 for a background process; NULL for a normal process |
| LATCHWAIT | VARCHAR2(8) | Address of latch the process is waiting for; NULL if none |
| LATCHSPIN | VARCHAR2(8) | Address of the latch the process is spinning on; NULL if none |
| PGA_USED_MEM | NUMBER | PGA memory currently used by the process |
| PGA_ALLOC_MEM | NUMBER | PGA memory currently allocated by the process (including free PGA memory not yet released to the operating system by the server process) |
| PGA_FREEABLE_MEM | NUMBER | Allocated PGA memory which can be freed |
| PGA_MAX_MEM | NUMBER | Maximum PGA memory ever allocated by the process |
| Column | Datatype | Description |
| SADDR | RAW(4 | 8) | Session address |
| SID | NUMBER | Session identifier |
| SERIAL# | NUMBER | Session serial number. Used to uniquely identify a session's objects. Guarantees that session-level commands are applied to the correct session objects if the session ends and another session begins with the same session ID. |
| AUDSID | NUMBER | Auditing session ID |
| PADDR | RAW(4 | 8) | Address of the process that owns the session |
| USER# | NUMBER | Oracle user identifier |
| USERNAME | VARCHAR2(30) | Oracle username |
| COMMAND | NUMBER | Command in progress (last statement parsed); for a list of values, see Table 7-5. These values also appear in the AUDIT_ACTIONS table. |
| OWNERID | NUMBER | The column contents are invalid if the value is 2147483644. Otherwise, this column contains the identifier of the user who owns the migratable session. For operations using Parallel Slaves, interpret this value as a 4-byte value. The low-order 2 bytes of which represent the session number, and the high-order bytes the instance ID of the query coordinator. |
| TADDR | VARCHAR2(8) | Address of transaction state object |
| LOCKWAIT | VARCHAR2(8) | Address of lock waiting for; null if none |
| STATUS | VARCHAR2(8) | Status of the session:
|
| SERVER | VARCHAR2(9) | Server type (DEDICATED| SHARED| PSEUDO| NONE) |
| SCHEMA# | NUMBER | Schema user identifier |
| SCHEMANAME | VARCHAR2(30) | Schema user name |
| OSUSER | VARCHAR2(30) | Operating system client user name |
| PROCESS | VARCHAR2(12) | Operating system client process ID |
| MACHINE | VARCHAR2(64) | Operating system machine name |
| TERMINAL | VARCHAR2(30) | Operating system terminal name |
| PROGRAM | VARCHAR2(48) | Operating system program name |
| TYPE | VARCHAR2(10) | Session type |
| SQL_ADDRESS | RAW(4 | 8) | Used with SQL_HASH_VALUE to identify the SQL statement that is currently being executed |
| SQL_HASH_VALUE | NUMBER | Used with SQL_ADDRESS to identify the SQL statement that is currently being executed |
| SQL_ID | VARCHAR2(13) | SQL identifier of the SQL statement that is currently being executed |
| SQL_CHILD_NUMBER | NUMBER | Child number of the SQL statement that is currently being executed |
| PREV_SQL_ADDR | RAW(4 | 8) | Used with PREV_HASH_VALUE to identify the last SQL statement executed |
| PREV_HASH_VALUE | NUMBER | Used with SQL_HASH_VALUE to identify the last SQL statement executed |
| PREV_SQL_ID | VARCHAR2(13) | SQL identifier of the last SQL statement executed |
| PREV_CHILD_NUMBER | NUMBER | Child number of the last SQL statement executed |
| MODULE | VARCHAR2(48) | Name of the currently executing module as set by calling theDBMS_APPLICATION_INFO.SET_MODULE procedure |
| MODULE_HASH | NUMBER | Hash value of the above MODULE |
| ACTION | VARCHAR2(32) | Name of the currently executing action as set by calling theDBMS_APPLICATION_INFO.SET_ACTION procedure |
| ACTION_HASH | NUMBER | Hash value of the above action name |
| CLIENT_INFO | VARCHAR2(64) | Information set by the DBMS_APPLICATION_INFO.SET_CLIENT_INFO procedure |
| FIXED_TABLE_SEQUENCE | NUMBER | This contains a number that increases every time the session completes a call to the database and there has been an intervening select from a dynamic performance table. This column can be used by performance monitors to monitor statistics in the database. Each time the performance monitor looks at the database, it only needs to look at sessions that are currently active or have a higher value in this column than the highest value that the performance monitor saw the last time. All the other sessions have been idle since the last time the performance monitor looked at the database. |
| ROW_WAIT_OBJ# | NUMBER | Object ID for the table containing the row specified in ROW_WAIT_ROW# |
| ROW_WAIT_FILE# | NUMBER | Identifier for the datafile containing the row specified in ROW_WAIT_ROW#. This column is valid only if the session is currently waiting for another transaction to commit and the value ofROW_WAIT_OBJ# is not -1. |
| ROW_WAIT_BLOCK# | NUMBER | Identifier for the block containing the row specified in ROW_WAIT_ROW#. This column is valid only if the session is currently waiting for another transaction to commit and the value ofROW_WAIT_OBJ# is not -1. |
| ROW_WAIT_ROW# | NUMBER | Current row being locked. This column is valid only if the session is currently waiting for another transaction to commit and the value of ROW_WAIT_OBJ# is not -1. |
| LOGON_TIME | DATE | Time of logon |
| LAST_CALL_ET | NUMBER | If the session STATUS is currently ACTIVE, then the value represents the elapsed time in seconds since the session has become active. If the session STATUS is currently INACTIVE, then the value represents the elapsed time in seconds since the session has become inactive. |
| PDML_ENABLED | VARCHAR2(3) | This column has been replaced by column PDML_STATUS |
| FAILOVER_TYPE | VARCHAR2(13) | Indicates whether and to what extent transparent application failover (TAF) is enabled for the session:
See Also:
|
| FAILOVER_METHOD | VARCHAR2(10) | Indicates the transparent application failover method for the session:
|
| FAILED_OVER | VARCHAR2(3) | Indicates whether the session is running in failover mode and failover has occurred (YES) or not (NO) |
| RESOURCE_CONSUMER_GROUP | VARCHAR2(32) | Name of the session's current resource consumer group |
| PDML_STATUS | VARCHAR2(8) | If ENABLED, the session is in a PARALLEL DML enabled mode. If DISABLED, PARALLEL DML enabled mode is not supported for the session. If FORCED, the session has been altered to force PARALLEL DML. |
| PDDL_STATUS | VARCHAR2(8) | If ENABLED, the session is in a PARALLEL DDL enabled mode. If DISABLED, PARALLEL DDL enabled mode is not supported for the session. If FORCED, the session has been altered to force PARALLEL DDL. |
| PQ_STATUS | VARCHAR2(8) | If ENABLED, the session is in a PARALLEL QUERY enabled mode. If DISABLED, PARALLEL QUERY enabled mode is not supported for the session. If FORCED, the session has been altered to force PARALLEL QUERY. |
| CURRENT_QUEUE_DURATION | NUMBER | If queued (1), the current amount of time the session has been queued. If not currently queued, the value is 0. |
| CLIENT_IDENTIFIER | VARCHAR2(64) | Client identifier of the session |
| BLOCKING_SESSION_STATUS | VARCHAR2(11) | Blocking session status:
|
| BLOCKING_INSTANCE | NUMBER | Instance identifier of blocking session |
| BLOCKING_SESSION | NUMBER | Session identifier of blocking session |
| SEQ# | NUMBER | Sequence number that uniquely identifies the wait. Incremented for each wait. |
| EVENT# | NUMBER | Event number |
| EVENT | VARCHAR2(64) | Resource or event for which the session is waiting See Also: Appendix C, "Oracle Wait Events" |
| P1TEXT | VARCHAR2(64) | Description of the first additional parameter |
| P1 | NUMBER | First additional parameter |
| P1RAW | RAW(4) | First additional parameter |
| P2TEXT | VARCHAR2(64) | Description of the second additional parameter |
| P2 | NUMBER | Second additional parameter |
| P2RAW | RAW(4) | Second additional parameter |
| P3TEXT | VARCHAR2(64) | Description of the third additional parameter |
| P3 | NUMBER | Third additional parameter |
| P3RAW | RAW(4) | Third additional parameter |
| WAIT_CLASS_ID | NUMBER | Identifier of the wait class |
| WAIT_CLASS# | NUMBER | Number of the wait class |
| WAIT_CLASS | VARCHAR2(64) | Name of the wait class |
| WAIT_TIME | NUMBER | A nonzero value is the session's last wait time. A zero value means the session is currently waiting. |
| SECONDS_IN_WAIT | NUMBER | If WAIT_TIME = 0, then SECONDS_IN_WAIT is the seconds spent in the current wait condition. IfWAIT_TIME > 0, then SECONDS_IN_WAIT is the seconds since the start of the last wait, andSECONDS_IN_WAIT - WAIT_TIME / 100 is the active seconds since the last wait ended. |
| STATE | VARCHAR2(19) | Wait state:
|
| SERVICE_NAME | VARCHAR2(64) | Service name of the session |
| SQL_TRACE | VARCHAR2(8) | Indicates whether SQL tracing is enabled (ENABLED) or disabled (DISABLED) |
| SQL_TRACE_WAITS | VARCHAR2(5) | Indicates whether wait tracing is enabled (TRUE) or not (FALSE) |
| SQL_TRACE_BINDS | VARCHAR2(5) | Indicates whether bind tracing is enabled (TRUE) or not (FALSE) |