yujun777 opened a new issue, #65808:
URL: https://github.com/apache/doris/issues/65808
### Description
A direct `MIN_DELTA` table stream on a MOW UNIQUE KEY table emits
`UPDATE_BEFORE` and `UPDATE_AFTER` when a key is inserted again after its
delete event has already been consumed. From the logical table perspective, the
second write should be an `APPEND`.
This reproduces without IVM and without materialized-view complete refresh.
### Reproduction
```sql
CREATE TABLE base_table (
k1 INT,
v1 INT
) UNIQUE KEY(k1)
DISTRIBUTED BY HASH(k1) BUCKETS 1
PROPERTIES (
"replication_num" = "1",
"binlog.enable" = "true",
"binlog.format" = "ROW",
"binlog.need_historical_value" = "true",
"enable_unique_key_merge_on_write" = "true"
);
CREATE STREAM base_stream ON TABLE base_table
PROPERTIES ("type" = "min_delta");
CREATE TABLE tmp_table (k1 INT, v1 INT)
DUPLICATE KEY(k1)
DISTRIBUTED BY HASH(k1) BUCKETS 1
PROPERTIES ("replication_num" = "1");
INSERT INTO base_table VALUES (1, 10);
DELETE FROM base_table WHERE k1 = 1;
INSERT INTO tmp_table SELECT * FROM base_stream;
INSERT INTO base_table VALUES (1, 10);
SET show_hidden_columns = true;
SELECT k1, v1,
__DORIS_STREAM_CHANGE_TYPE_COL__,
__DORIS_STREAM_SEQUENCE_COL__
FROM base_stream;
```
### Actual result
```text
k1 v1 __DORIS_STREAM_CHANGE_TYPE_COL__ __DORIS_STREAM_SEQUENCE_COL__
1 NULL UPDATE_BEFORE <sequence>
1 10 UPDATE_AFTER <sequence>
```
The initial insert followed by delete is consumed by the `INSERT INTO
tmp_table SELECT * FROM base_stream` statement, and the stream offset is
advanced before the second insert.
### Expected result
The second insert should be returned as one logical `APPEND` row, because
the key is absent from the visible table state after the delete was consumed.
### Suspected area
MOW keeps a delete tombstone physically. A subsequent write for that key
appears to be classified as `ROW_BINLOG_UPDATE` instead of `ROW_BINLOG_APPEND`,
after which `MIN_DELTA` expands it to `UPDATE_BEFORE` plus `UPDATE_AFTER`.
Relevant code paths include `historical_row_retriever.cpp` and
`block_reader.cpp`.
### Related issues
- [#65265](https://github.com/apache/doris/issues/65265)
- [#65418](https://github.com/apache/doris/issues/65418)
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