1. Before this PR if rowset does not contain column which should be read for related SlotDescriptor will call `insert_default` to column, but it's not this real defautl value.Real default value relevant information should be provided by the frontend side.
2. Support fetch when light schema change is not enabled, but disable for AGG or UNIQUE MOR model
In the case of rowets non-overlap and desc sorting, the logic of VCollectIterator::Level0Iterator::init_for_union will be followed. In this function, the row ref pos of the first level0 iterator is set to 0, and the row pos of other level0 iterators are all Set to -1.
But in the level1iterator, when rowets are non-overlapping and is ordering by desc, the list of rowset iterators will be reversed, causing the row ref pos of the first level0 iterator in the list to be -1, causing the block reader to think that the entire tablet has no data.
bug: some chinese word not sort by pinyin in GBK coding
CREATE TABLE `test_convert` (
`a` varchar(100) NULL
) ENGINE=OLAP
DUPLICATE KEY(`a`)
DISTRIBUTED BY HASH(`a`) BUCKETS 3
PROPERTIES (
"replication_allocation" = "tag.location.default: 1"
);
insert into test_convert values("b"), ("a"), ("c"), ("睿"), ("多"), ("丝");
Query OK, 6 rows affected (0.03 sec)
{'label':'insert_ca73a6acc2194d5b_888218a3949355a6', 'status':'VISIBLE', 'txnId':'18068'}
mysql [test]>select * from test_convert;
+------+
| a |
+------+
| a |
| c |
| 丝 |
| b |
| 多 |
| 睿 |
+------+
6 rows in set (0.01 sec)
mysql [test]>select * from test_convert order by convert(a using gbk);
+------+
| a |
+------+
| a |
| b |
| c |
| 多 |
| 丝 |
| 睿 |
+------+
6 rows in set (0.01 sec)
```
create table tbl1 (k1 varchar(100), k2 string) distributed by hash(k1) buckets 1 properties("replication_num" = "1");
insert into tbl1 values(1, "alice");
select cast(k1 as INT) as id from tbl1 order by id limit 2;
```
The above query could pass `checkEnableTwoPhaseRead` since the order by element is SlotRef but actually it's an function call expr
