Merge pull request #1207 from dronord/ora_fetch

fix and optimize oracle fetch
(cherry picked from commit f7e45ba)

modules/db_oracle/res.c

@@ -373,7 +373,7 @@ static int get_rows(ora_con_t* con, db_res_t* _r, OCIStmt* _c, dmap_t* _d)
 	// timelimited operation
 	status = begin_timelimit(con, 0);
 	if (status != OCI_SUCCESS) goto ora_err;
-	do status = OCIStmtFetch2(_c, con->errhp, 1, OCI_FETCH_NEXT, 0,
+	do status = OCIStmtFetch2(_c, con->errhp, 1, OCI_FETCH_LAST, 0,
 		OCI_DEFAULT);
 	while (wait_timelimit(con, status));
 	if (done_timelimit(con, status)) goto stop_load;
@@ -394,6 +394,13 @@ static int get_rows(ora_con_t* con, db_res_t* _r, OCIStmt* _c, dmap_t* _d)
 		goto stop_load;
 	}
 
+	if (rcnt > 5) {
+		ub4 prefetch = rcnt/5;
+		status = OCIAttrSet(_c, OCI_HTYPE_STMT, &prefetch, 0,
+			OCI_ATTR_PREFETCH_ROWS, con->errhp);
+		if (status != OCI_SUCCESS) goto ora_err;
+	}
+
 	RES_ROW_N(_r) = rcnt;
 	if (db_allocate_rows( _r, rcnt)!=0) {
 		LM_ERR("no private memory left\n");