fix the bug of incorrect ROWNUM in partition table

src/gausskernel/runtime/executor/nodePartIterator.cpp

@@ -141,6 +141,7 @@ TupleTableSlot* ExecPartIterator(PartIteratorState* node)
     if (!TupIsNull(slot))
         return slot;
 
+    node->ps.lefttree->ps_rownum--;
     /* switch to next partition until we get a unempty tuple */
     for (;;) {
         if (node->currentItr + 1 >= partitionScan) /* have scanned all partitions */

src/test/regress/expected/xc_rownum.out

@@ -1640,3 +1640,119 @@ select * from test where id < 2 union select * from (select * from test order by
 
 drop table student;
 drop table test;
+--test partition table
+-- partition by RANGE
+CREATE TABLE partition_range (c1 int , c2 int)
+ PARTITION BY RANGE (c2) (
+ PARTITION p1 START(1) END(1000),
+ PARTITION p2 END(2000),
+ PARTITION p3 START(2000) END(2500)
+);
+insert into partition_range values(1,200);
+insert into partition_range values(1,300);
+insert into partition_range values(1,400);
+insert into partition_range values(1,1500);
+insert into partition_range values(1,1600);
+insert into partition_range values(1,1700);
+insert into partition_range values(1,2100);
+insert into partition_range values(1,2300);
+select rownum,* from partition_range;
+ rownum | c1 |  c2  
+--------+----+------
+      1 |  1 |  200
+      2 |  1 |  300
+      3 |  1 |  400
+      4 |  1 | 1500
+      5 |  1 | 1600
+      6 |  1 | 1700
+      7 |  1 | 2100
+      8 |  1 | 2300
+(8 rows)
+
+select * from partition_range where rownum < 5;
+ c1 |  c2  
+----+------
+  1 |  200
+  1 |  300
+  1 |  400
+  1 | 1500
+(4 rows)
+
+drop table partition_range;
+-- partition by LIST
+create table partition_list(id int,name varchar,age int)
+partition by list(id)
+(partition p1 values(10),
+ partition p2 values(20),
+ partition p3 values(30),
+ partition p4 values(40)
+);
+insert into partition_list values(10,'ten',10);
+insert into partition_list values(10,'thirteen',13);
+insert into partition_list values(20,'twenty',20);
+insert into partition_list values(20,'twenty-three',23);
+insert into partition_list values(30,'thirty',30);
+insert into partition_list values(30,'Thirty-three',33);
+insert into partition_list values(40,'forty',40);
+insert into partition_list values(40,'forty-three',43);
+select rownum,* from partition_list;
+ rownum | id |     name     | age 
+--------+----+--------------+-----
+      1 | 40 | forty        |  40
+      2 | 40 | forty-three  |  43
+      3 | 30 | thirty       |  30
+      4 | 30 | Thirty-three |  33
+      5 | 20 | twenty       |  20
+      6 | 20 | twenty-three |  23
+      7 | 10 | ten          |  10
+      8 | 10 | thirteen     |  13
+(8 rows)
+
+select * from partition_list where rownum < 5;
+ id |     name     | age 
+----+--------------+-----
+ 40 | forty        |  40
+ 40 | forty-three  |  43
+ 30 | thirty       |  30
+ 30 | Thirty-three |  33
+(4 rows)
+
+drop table partition_list;
+-- partition by HASH
+create table partition_hash(id int,name varchar,age int)
+partition by hash(id)
+(partition p1,
+ partition p2,
+ partition p3
+);
+insert into partition_hash values(10,'ten',10);
+insert into partition_hash values(10,'thirteen',13);
+insert into partition_hash values(20,'twenty',20);
+insert into partition_hash values(20,'twenty-three',23);
+insert into partition_hash values(30,'thirty',30);
+insert into partition_hash values(30,'Thirty-three',33);
+insert into partition_hash values(40,'forty',40);
+insert into partition_hash values(40,'forty-three',43);
+select rownum,* from partition_hash;
+ rownum | id |     name     | age 
+--------+----+--------------+-----
+      1 | 30 | thirty       |  30
+      2 | 30 | Thirty-three |  33
+      3 | 40 | forty        |  40
+      4 | 40 | forty-three  |  43
+      5 | 20 | twenty       |  20
+      6 | 20 | twenty-three |  23
+      7 | 10 | ten          |  10
+      8 | 10 | thirteen     |  13
+(8 rows)
+
+select * from partition_hash where rownum < 5;
+ id |     name     | age 
+----+--------------+-----
+ 30 | thirty       |  30
+ 30 | Thirty-three |  33
+ 40 | forty        |  40
+ 40 | forty-three  |  43
+(4 rows)
+
+drop table partition_hash;

src/test/regress/sql/xc_rownum.sql

@@ -462,3 +462,71 @@ select * from test where id < 2 union select * from (select * from test order by
 
 drop table student;
 drop table test;
+
+--test partition table
+-- partition by RANGE
+CREATE TABLE partition_range (c1 int , c2 int)
+ PARTITION BY RANGE (c2) (
+ PARTITION p1 START(1) END(1000),
+ PARTITION p2 END(2000),
+ PARTITION p3 START(2000) END(2500)
+);
+
+insert into partition_range values(1,200);
+insert into partition_range values(1,300);
+insert into partition_range values(1,400);
+insert into partition_range values(1,1500);
+insert into partition_range values(1,1600);
+insert into partition_range values(1,1700);
+insert into partition_range values(1,2100);
+insert into partition_range values(1,2300);
+
+select rownum,* from partition_range;
+select * from partition_range where rownum < 5;
+
+drop table partition_range;
+
+-- partition by LIST
+create table partition_list(id int,name varchar,age int)
+partition by list(id)
+(partition p1 values(10),
+ partition p2 values(20),
+ partition p3 values(30),
+ partition p4 values(40)
+);
+
+insert into partition_list values(10,'ten',10);
+insert into partition_list values(10,'thirteen',13);
+insert into partition_list values(20,'twenty',20);
+insert into partition_list values(20,'twenty-three',23);
+insert into partition_list values(30,'thirty',30);
+insert into partition_list values(30,'Thirty-three',33);
+insert into partition_list values(40,'forty',40);
+insert into partition_list values(40,'forty-three',43);
+
+select rownum,* from partition_list;
+select * from partition_list where rownum < 5;
+
+drop table partition_list;
+
+-- partition by HASH
+create table partition_hash(id int,name varchar,age int)
+partition by hash(id)
+(partition p1,
+ partition p2,
+ partition p3
+);
+
+insert into partition_hash values(10,'ten',10);
+insert into partition_hash values(10,'thirteen',13);
+insert into partition_hash values(20,'twenty',20);
+insert into partition_hash values(20,'twenty-three',23);
+insert into partition_hash values(30,'thirty',30);
+insert into partition_hash values(30,'Thirty-three',33);
+insert into partition_hash values(40,'forty',40);
+insert into partition_hash values(40,'forty-three',43);
+
+select rownum,* from partition_hash;
+select * from partition_hash where rownum < 5;
+
+drop table partition_hash;