SPI_finish — disconnect a procedure from the SPI manager
int SPI_finish(void)
   SPI_finish closes an existing connection to
   the SPI manager.  You must call this function after completing the
   SPI operations needed during your procedure's current invocation.
   You do not need to worry about making this happen, however, if you
   abort the transaction via elog(ERROR).  In that
   case SPI will clean itself up automatically.
  
SPI_OK_FINISHif properly disconnected
SPI_ERROR_UNCONNECTEDif called from an unconnected procedure