Unexpected Estimated Rows of `OR`

[bajinsheng]

Bug Report

The number of Estimated Rows in the query plan is unexpected.

1. Minimal reproduce step (Required)

CREATE TABLE t0(c0 INT);
INSERT INTO t0 VALUES(0), (1), (2), (3), (4), (5), (6), (7), (8), (9);
ANALYZE TABLE t0;

EXPLAIN SELECT * FROM t0  WHERE TRUE; -- estimated rows: 10.00
EXPLAIN SELECT * FROM t0  WHERE (TRUE)OR(TO_BASE64(t0.c0)); -- estimated rows: 8.00

2. What did you expect to see? (Required)

The estimated rows of the second SELECT should be 10.0.

3. What did you see instead (Required)

The estimated rows of the second SELECT is 8.0.

As a reference, this result is expected if another expression is used as the right operand of the OR:

EXPLAIN SELECT * FROM t0  WHERE (TRUE)OR((t0.c0>0); -- estimated rows: 10.00

4. What is your TiDB version? (Required)

| Release Version: v6.4.0-alpha-12-g51a6684fb
Edition: Community
Git Commit Hash: 51a6684fb767cfd86a8312e0e6447963b927c791
Git Branch: master
UTC Build Time: 2022-10-05 12:40:23
GoVersion: go1.19.1
Race Enabled: false
TiKV Min Version: 6.2.0-alpha
Check Table Before Drop: false
Store: unistore |