1. 先通过top命令查看产用资源较多的spid号

2.查询当前耗时的会话ID，用户名，sqlID等： select sid,serial#,machine,username,program,sql_hash_value,sql_id,        to_char(logon_time,‘yyyy/mm/dd hh24:mi:ss‘) as login_time from v$session where paddr in (select addr from v$process where spid in (‘5648612‘,‘256523‘));

3. 如果上一步sql_id或者 hash_value不为空，则可用v$sqlarea查出当前正在使用的sql select sql_text   from v$sqltext_with_newlines   where hash_value = http://www.mamicode.com/&hash_value order by piece;
select * from v$sql where sql_id=‘‘

---CSDN 网友提供的----

SELECT sql_text   FROM v$sqltext a WHERE (a.hash_value, a.address) IN        (SELECT DECODE(sql_hash_value, 0, prev_hash_value, sql_hash_value),                DECODE(sql_hash_value, 0, prev_sql_addr, sql_address)           FROM v$session b          WHERE b.paddr = (SELECT addr FROM v$process c WHERE c.spid = ‘&pid‘)) ORDER BY piece ASC