postgresql执行一个查询时报了如下一个错误
: An I/O error occured while sending to the backend.
at .(:281)
at .jdbc2.(:555)
at .jdbc2.(:403)
at .jdbc2.(:331)
at com.(:237)
at com.(:54)
at com.(:127)
at com.(:79)
at com.(:30)
at com.(:73)
at com.(:90)
at com.(:25)
at (:709)
at (:802)
at (:237)
at (:157)
at (:214)
at (:104)
at (:520)
at (:198)
at (:152)
at (:104)
at (:520)
at (:137)
at (:104)
at (:118)
at (:102)
at (:520)
at (:109)
at (:104)
at (:520)
at (:929)
at .(:160)
at .http11.(:799)
at .http11.Http11Protocol$(:705)
at (:577)
at $(:683)
at (:662)
Caused by: : Socket closed
at .socketRead0(Native Method)
at (:129)
at (:143)
at (:112)
at (:71)
at (:269)
at .(:1700)
at .(:255)
这是为什么，如何解决这个问题？