create or replace table t(
id int,
KEY_TYPE(id),
x int,
row_start SYS_DATATYPE as row start invisible,
row_end SYS_DATATYPE as row end invisible,
period for system_time(row_start, row_end)
) with system versioning;
insert t values (1, 2);
replace t values (1, 3);
select *, current_row(row_end) as current from t for system_time all order by x;
id	x	current
1	2	0
1	3	1
drop table t;
create table t (
id int unique,
x int,
row_start SYS_DATATYPE as row start invisible,
row_end SYS_DATATYPE as row end invisible,
period for system_time (row_start, row_end)
) with system versioning;
insert t values (1, 2);
replace t values (1, 3);
select *, current_row(row_end) as current from t for system_time all order by x;
id	x	current
1	2	0
1	3	1
drop table t;
# MDEV-15645 Assertion `table->insert_values' failed in write_record upon REPLACE into a view with underlying versioned table
create or replace table t1 (a int, b int, primary key (a), unique(b)) with system versioning;
insert into t1 values (1,1);
create or replace table t2 (c int);
create or replace view v as select t1.* from t1 join t2;
replace into v (a, b) select a, b from t1;
drop view v;
drop tables t1, t2;
CREATE TABLE t1 (
pk INT AUTO_INCREMENT,
f INT,
row_start SYS_DATATYPE AS ROW START INVISIBLE,
row_end SYS_DATATYPE AS ROW END INVISIBLE,
PRIMARY KEY(pk),
UNIQUE(f),
PERIOD FOR SYSTEM_TIME(row_start, row_end)
) WITH SYSTEM VERSIONING;
INSERT INTO t1 () VALUES (),(),(),(),(),();
UPDATE IGNORE t1 SET f = 1;
REPLACE t1 SELECT * FROM t1;
DROP TABLE t1;
# MDEV-22540 ER_DUP_ENTRY upon REPLACE or Assertion failed
set timestamp=1589245268.41934;
create table t1 (a int primary key) with system versioning;
insert into t1 values (1),(2);
connect  con1,localhost,root,,test;
set timestamp=1589245268.52093;
replace into t1 values (1),(2);
connection default;
replace into t1 values (1),(2);
connection con1;
replace into t1 values (1),(2);
ERROR 23000: Duplicate entry '1' for key 'PRIMARY'
drop table t1;