資料泵匯出出現ORA-31623錯誤

客戶資料庫在調整SGA後，匯出出現ORA-31623錯誤。

Oracle對於這個錯誤的描述為：

ORA-31623: a job is not attached to this session via the specified handle
Cause: An attempt to reference a job using a handle which is invalid or no longer valid for the current session.
Action: Select a handle corresponding to a valid active job or start a new job.

從這個錯誤看不出導致問題的真正原因，不過從告警日誌中可以發現進一步的資訊：

Tue Jan 17 19:30:08 2012
Errors in file /opt/oracle/diag/rdbms/mobiledb_n/mobiledb/trace/mobiledb_ora_17167.trc (incident=84810):
ORA-04031: unable to allocate 56 bytes of shared memory ("streams pool","unknown object","streams pool","fixed allocation callback")
Incident details in: /opt/oracle/diag/rdbms/mobiledb_n/mobiledb/incident/incdir_84810/mobiledb_ora_17167_i84810.trc
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
Tue Jan 17 19:30:11 2012
Dumping diagnostic data in directory=[cdmp_20120117193011], requested by (instance=1, sid=17167), summary=[incident=84810].
Tue Jan 17 19:30:12 2012
Sweep [inc][84810]: completed
Sweep [inc2][84810]: completed

資料庫在嘗試分配STREAMS POOL的時候出現了ORA-4031錯誤。此時查詢V$MEMORY_RESIZE_OPS檢視，發現同一時間大量的STREAMS POOL擴充套件失敗的記錄，Oracle嘗試分配STREAMS POOL但是目前資料庫的記憶體採用了在SGA_TARGET下手工分配的方式，為了避免Oracle記憶體的動態調整，所有的記憶體元件已經將記憶體全部使用，因此STREAMS POOL無法獲取到空間。

解決問題的方法很簡單，手工收縮DB_CACHE_SIZE或SHARED_POOL_SIZE的值，分配給STREAMS POOL，就可以避免這個錯誤，不過資料泵的匯出還要使用STREAMS POOL，還是第一次發現這個問題。