执行此sql后，没有更多数据可从套接字读取

Question

为什么当我使用SQL Developer执行此SQL时

No more data to read from socket

但是当我重新连接该连接然后删除fetch next 5 rows only时，它执行得很好吗？

当我在Web应用程序上执行此查询时，也会发生此错误：

oci_execute(): ORA-03113: end-of-file on communication channel
Process ID: 4136
Session ID: 18
Serial number: 36957 

SELECT PO_ID,
       ENQ_ID,
       TITLE,
       SYS_BRKDWN_ID,
       TECH_HAND_USR_ID,
       PROJ_NO,
       SUPPL_NO,
       approver_usr_id,
       VER
FROM   S181 
WHERE  approver_usr_id ='EETEC'
and    reject_date is null
AND    po_hdr_biz.can_approve(po_id, enq_id, ver,'EETEC') = 1
AND    EXISTS (
  SELECT NULL
  FROM   po_approvals
  WHERE  po_approvals.po_id = s181.po_id
  AND    po_approvals.ver = s181.ver
  AND    po_approvals.init = 'EETEC'
  AND    po_approvals.init = s181.approver_usr_id
  AND    po_approvals.po_id IS NOT NULL
  AND    po_approvals.approve_date IS NULL
UNION
  SELECT NULL
  FROM   po_approvals
  WHERE  po_approvals.enq_id = s181.enq_id 
  AND    po_approvals.ver = s181.ver 
  AND    po_approvals.init = 'EETEC'
  AND    po_approvals.init = s181.approver_usr_id 
  AND    po_approvals.enq_id IS NOT NULL
  FETCH NEXT 5 ROWS ONLY
);