Tikv cast string as decimal function inconsistent behavior with tidb

[yibin87]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

set tidb_opt_projection_push_down = 'on';
Case1
create table t1(s1 time);
insert into t1 values ('11:11:11');
select cast(s1 as decimal(7,2)) from t1;
--Expect
99999.99
--Actual
100000

Case2
set tidb_opt_projection_push_down = 'on';
CREATE TABLE t1 (v varchar(10), tt tinytext, t text, mt mediumtext, lt longtext);
INSERT INTO t1 VALUES ('1.01', '2.02', '3.03', '4.04', '5.05');
SELECT CAST(v AS DECIMAL), CAST(tt AS DECIMAL), CAST(t AS DECIMAL),
CAST(mt AS DECIMAL), CAST(lt AS DECIMAL) from t1;
--Expect
CAST(v AS DECIMAL) CAST(tt AS DECIMAL) CAST(t AS DECIMAL) CAST(mt AS DECIMAL) CAST(lt AS DECIMAL)
1 2 3 4 5
--Actual
CAST(v AS DECIMAL) CAST(tt AS DECIMAL) CAST(t AS DECIMAL) CAST(mt AS DECIMAL) CAST(lt AS DECIMAL)
1.00 2.00 3.00 4.00 5.00

2. What is your TiDB version? (Required)

| Release Version: v7.4.0-alpha-2012-gfe01d11df6-dirty
Edition: Community
Git Commit Hash: fe01d11
Git Branch: div_increase_prec
UTC Build Time: 2024-03-15 08:10:07

[yibin87]

Checked tidb is consistent with mysql

[yibin87]

/assign @yibin87

[yibin87]

/assign @gengliqi

[yibin87]

#52644, tikv also differs from tidb in whether produces warning msgs.

[gengliqi]

should be closed due to tikv/tikv#16913 is closed