Equivalent view extraction rounds VAR_SAMP results

[123lpygithub]

Under semantic-equivalent rewriting, the source and mutated queries are logically equivalent, but produce different results on PolarDB-X.

Version: 5.4.19-SNAPSHOT

How to repeat:

DROP DATABASE IF EXISTS vect_submit_c2;
CREATE DATABASE vect_submit_c2;
USE vect_submit_c2;

CREATE TABLE t3 (
  c3 INT
);

INSERT INTO t3 VALUES
  (0),
  (0),
  (1);

-- Source Original SQL
SELECT VAR_SAMP(c3) AS var_samp_c3
FROM t3;

-- View SQL
CREATE VIEW v_t3 AS
SELECT VAR_SAMP(c3) AS var_samp_c3
FROM t3;

-- Mutated SQL
SELECT var_samp_c3
FROM v_t3;

Observed result - Query A (original):

var_samp_c3
0.33333333333333337

Observed result - Query B (mutated):

var_samp_c3
0.3334