修复BRI触发器 + copy的内存持续增长问题

在原有的函数CopyFrom实现中，如果迭代中的元组无需插入(skip_tuple=true, BRI触发器会引起此情况），此种情况出现时
会导致per-tuple memory context不会reset，如果所有的元组均被触发器转移，会导致该内存上下文不断增长。
本次提交修复了此问题。
发生skip_tuple的情况，必然是BRI存在，可以在每次迭代都安全reset per-tuple memory context。
另：foreign table也需要每次reset（不会存在bulk insert的情况），本提交一并修复。

src/gausskernel/optimizer/commands/copy.cpp

@@ -4282,7 +4282,7 @@ uint64 CopyFrom(CopyState cstate)
      */
     if ((resultRelInfo->ri_TrigDesc != NULL &&
         (resultRelInfo->ri_TrigDesc->trig_insert_before_row || resultRelInfo->ri_TrigDesc->trig_insert_instead_row)) ||
-        cstate->volatile_defexprs) {
+        cstate->volatile_defexprs || isForeignTbl) {
         useHeapMultiInsert = false;
     } else {
         useHeapMultiInsert = true;
@@ -4819,6 +4819,8 @@ uint64 CopyFrom(CopyState cstate)
 
             if (!skip_tuple && isForeignTbl) {
                 resultRelInfo->ri_FdwRoutine->ExecForeignInsert(estate, resultRelInfo, slot, NULL);
+                Assert(!useHeapMultiInsert);
+                resetPerTupCxt = true;
                 processed++;
             } else if (!skip_tuple) {
                 /*
@@ -5004,6 +5006,14 @@ uint64 CopyFrom(CopyState cstate)
                  * tuples inserted by an INSERT command.
                  */
                 processed++;
+            } else {/*skip_tupe == true*/
+                /*
+                 * only the before row insert trigget would make skip_tupe==true
+                 * which useHeapMultiInsert must be false
+                 * so we can safely reset the per-tuple memory context in next iteration
+                 */
+                Assert(useHeapMultiInsert == false);
+                resetPerTupCxt = true;
             }
 #ifdef PGXC
         }

src/test/regress/expected/copy2.out

@@ -321,3 +321,45 @@ DROP TABLE x;
 DROP TABLE y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
+CREATE TABLE measurement (
+city_id int not null,
+logdate int not null,
+peaktemp int,
+unitsales int
+);
+CREATE TABLE measurement_movement (
+city_id int not null,
+logdate int not null,
+peaktemp int,
+unitsales int
+);
+CREATE OR REPLACE FUNCTION measurement_insert_trigger()
+RETURNS TRIGGER AS $$
+BEGIN
+INSERT INTO measurement_movement VALUES (NEW.*);
+RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+CREATE TRIGGER insert_measurement_trigger
+BEFORE INSERT ON measurement
+FOR EACH ROW EXECUTE PROCEDURE measurement_insert_trigger();
+COPY measurement from stdin;
+select * from measurement_movement order by city_id;
+ city_id | logdate | peaktemp | unitsales 
+---------+---------+----------+-----------
+   10001 |      22 |       32 |        42
+   10002 |      23 |       33 |        43
+   10003 |      24 |       34 |        44
+   10004 |      25 |       35 |        45
+   10005 |      26 |       36 |        46
+(5 rows)
+
+select * from measurement order by city_id;
+ city_id | logdate | peaktemp | unitsales 
+---------+---------+----------+-----------
+(0 rows)
+
+drop trigger insert_measurement_trigger on measurement;
+drop function measurement_insert_trigger;
+drop table measurement;
+drop table measurement_movement;

src/test/regress/sql/copy2.sql

@@ -228,3 +228,46 @@ DROP TABLE x;
 DROP TABLE y;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();
+
+
+CREATE TABLE measurement (
+city_id int not null,
+logdate int not null,
+peaktemp int,
+unitsales int
+);
+
+CREATE TABLE measurement_movement (
+city_id int not null,
+logdate int not null,
+peaktemp int,
+unitsales int
+);
+
+CREATE OR REPLACE FUNCTION measurement_insert_trigger()
+RETURNS TRIGGER AS $$
+BEGIN
+INSERT INTO measurement_movement VALUES (NEW.*);
+RETURN NULL;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER insert_measurement_trigger
+BEFORE INSERT ON measurement
+FOR EACH ROW EXECUTE PROCEDURE measurement_insert_trigger();
+
+COPY measurement from stdin;
+10001	22	32	42
+10002	23	33	43
+10003	24	34	44
+10004	25	35	45
+10005	26	36	46
+\.
+
+select * from measurement_movement order by city_id;
+select * from measurement order by city_id;
+
+drop trigger insert_measurement_trigger on measurement;
+drop function measurement_insert_trigger;
+drop table measurement;
+drop table measurement_movement;