*** a/contrib/postgres_fdw/connection.c
--- b/contrib/postgres_fdw/connection.c
***************
*** 598,603 **** pgfdw_xact_callback(XactEvent event, void *arg)
--- 598,623 ----
  				case XACT_EVENT_ABORT:
  					/* Assume we might have lost track of prepared statements */
  					entry->have_error = true;
+ 					/*
+ 					 * If we had submitted a command to the remote server using
+ 					 * an asynchronous execution function, the command might
+ 					 * have not yet completed.  Check to see if a command is
+ 					 * still being processed by the remote server, and if so,
+ 					 * request cancellation of the command; if not, abort
+ 					 * gracefully.
+ 					 */
+ 					if (PQtransactionStatus(entry->conn) == PQTRANS_ACTIVE)
+ 					{
+ 						PGcancel   *cancel;
+ 						char		errbuf[256];
+ 
+ 						if ((cancel = PQgetCancel(entry->conn)))
+ 						{
+ 							PQcancel(cancel, errbuf, sizeof(errbuf));
+ 							PQfreeCancel(cancel);
+ 						}
+ 						break;
+ 					}
  					/* If we're aborting, abort all remote transactions too */
  					res = PQexec(entry->conn, "ABORT TRANSACTION");
  					/* Note: can't throw ERROR, it would be infinite loop */
*** a/contrib/postgres_fdw/postgres_fdw.c
--- b/contrib/postgres_fdw/postgres_fdw.c
***************
*** 32,37 ****
--- 32,38 ----
  #include "optimizer/var.h"
  #include "optimizer/tlist.h"
  #include "parser/parsetree.h"
+ #include "storage/latch.h"
  #include "utils/builtins.h"
  #include "utils/guc.h"
  #include "utils/lsyscache.h"
***************
*** 3131,3136 **** execute_dml_stmt(ForeignScanState *node)
--- 3132,3138 ----
  	ExprContext *econtext = node->ss.ps.ps_ExprContext;
  	int			numParams = dmstate->numParams;
  	const char **values = dmstate->param_values;
+ 	int			wc;
  
  	/*
  	 * Construct array of query parameter values in text format.
***************
*** 3151,3158 **** execute_dml_stmt(ForeignScanState *node)
  	 * We don't use a PG_TRY block here, so be careful not to throw error
  	 * without releasing the PGresult.
  	 */
! 	dmstate->result = PQexecParams(dmstate->conn, dmstate->query,
! 								   numParams, NULL, values, NULL, NULL, 0);
  	if (PQresultStatus(dmstate->result) !=
  		(dmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK))
  		pgfdw_report_error(ERROR, dmstate->result, dmstate->conn, true,
--- 3153,3188 ----
  	 * We don't use a PG_TRY block here, so be careful not to throw error
  	 * without releasing the PGresult.
  	 */
! 	if (!PQsendQueryParams(dmstate->conn, dmstate->query, numParams,
! 						   NULL, values, NULL, NULL, 0))
! 		pgfdw_report_error(ERROR, NULL, dmstate->conn, true, dmstate->query);
! 
! 	/*
! 	 * Receive data until PQgetResult is ready to get the result without
! 	 * blocking.
! 	 */
! 	while (PQisBusy(dmstate->conn))
! 	{
! 		/* Sleep until there's something to do */
! 		wc = WaitLatchOrSocket(MyLatch,
! 							   WL_LATCH_SET | WL_SOCKET_READABLE,
! 							   PQsocket(dmstate->conn),
! 							   -1L);
! 		ResetLatch(MyLatch);
! 
! 		CHECK_FOR_INTERRUPTS();
! 
! 		/* Data available in socket */
! 		if (wc & WL_SOCKET_READABLE)
! 		{
! 			if (!PQconsumeInput(dmstate->conn))
! 				pgfdw_report_error(ERROR, NULL, dmstate->conn, true,
! 								   dmstate->query);
! 		}
! 	}
! 
! 	/* Get the result */
! 	dmstate->result = PQgetResult(dmstate->conn);
  	if (PQresultStatus(dmstate->result) !=
  		(dmstate->has_returning ? PGRES_TUPLES_OK : PGRES_COMMAND_OK))
  		pgfdw_report_error(ERROR, dmstate->result, dmstate->conn, true,