create table t (a int) with system versioning;
insert into t values (1);
update t set a= 2;
show global variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	DEFAULT
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	DEFAULT
select * from t;
a
2
set system_versioning_asof= '2031-1-1 0:0:0';
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	2031-01-01 00:00:00.000000
select * from t;
a
2
set system_versioning_asof= '2011-1-1 0:0:0';
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	2011-01-01 00:00:00.000000
select * from t;
a
set global system_versioning_asof= 'alley';
ERROR 42000: Variable 'system_versioning_asof' can't be set to the value of 'alley'
set global system_versioning_asof= null;
ERROR 42000: Variable 'system_versioning_asof' can't be set to the value of 'NULL'
set global system_versioning_asof= 1;
ERROR 42000: Incorrect argument type to variable 'system_versioning_asof'
set global system_versioning_asof= 1.1;
ERROR 42000: Incorrect argument type to variable 'system_versioning_asof'
set system_versioning_asof= 'alley';
ERROR 42000: Variable 'system_versioning_asof' can't be set to the value of 'alley'
set system_versioning_asof= null;
ERROR 42000: Variable 'system_versioning_asof' can't be set to the value of 'NULL'
set system_versioning_asof= 1;
ERROR 42000: Incorrect argument type to variable 'system_versioning_asof'
set system_versioning_asof= 1.1;
ERROR 42000: Incorrect argument type to variable 'system_versioning_asof'
# GLOBAL @@system_versioning_asof
set global system_versioning_asof= '1911-11-11 11:11:11.1111119';
Warnings:
Note	1292	Truncated incorrect datetime value: '1911-11-11 11:11:11.1111119'
Note	1292	Truncated incorrect datetime value: '1911-11-11 11:11:11.1111119'
show global variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1911-11-11 11:11:11.111111
set global system_versioning_asof= '1900-01-01 00:00:00';
show global variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1900-01-01 00:00:00.000000
set global system_versioning_asof= timestamp'1911-11-11 11:11:11.1111119';
Warnings:
Note	1292	Truncated incorrect DATETIME value: '1911-11-11 11:11:11.1111119'
show global variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1911-11-11 11:11:11.111111
set @ts= timestamp'1900-01-01 00:00:00';
set global system_versioning_asof= @ts;
show global variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1900-01-01 00:00:00.000000
set global system_versioning_asof= default;
select @@global.system_versioning_asof;
@@global.system_versioning_asof
DEFAULT
# SESSION @@system_versioning_asof
set system_versioning_asof= '1911-11-11 11:11:11.1111119';
Warnings:
Note	1292	Truncated incorrect datetime value: '1911-11-11 11:11:11.1111119'
Note	1292	Truncated incorrect datetime value: '1911-11-11 11:11:11.1111119'
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1911-11-11 11:11:11.111111
set system_versioning_asof= '1900-01-01 00:00:00';
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1900-01-01 00:00:00.000000
set system_versioning_asof= timestamp'1911-11-11 11:11:11.1111119';
Warnings:
Note	1292	Truncated incorrect DATETIME value: '1911-11-11 11:11:11.1111119'
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1911-11-11 11:11:11.111111
set @ts= timestamp'1900-01-01 00:00:00';
set system_versioning_asof= @ts;
show variables like 'system_versioning_asof';
Variable_name	Value
system_versioning_asof	1900-01-01 00:00:00.000000
# DEFAULT: value is copied from GLOBAL to SESSION
set global system_versioning_asof= timestamp'1911-11-11 11:11:11.111111';
set system_versioning_asof= '1900-01-01 00:00:00';
select @@global.system_versioning_asof != @@system_versioning_asof as different;
different
1
set system_versioning_asof= default;
select @@global.system_versioning_asof = @@system_versioning_asof as equal;
equal
1
set global system_versioning_asof= DEFAULT;
set system_versioning_asof= DEFAULT;
select @@global.system_versioning_asof, @@system_versioning_asof;
@@global.system_versioning_asof	@@system_versioning_asof
DEFAULT	DEFAULT
select * from t for system_time all;
a
2
1
select * from t;
a
2
select * from t for system_time as of timestamp current_timestamp(6);
a
2
select * from t for system_time all;
a
2
1
select * from t for system_time from '0-0-0' to current_timestamp(6);
a
2
1
select * from t for system_time between '0-0-0' and current_timestamp(6);
a
2
1
show status like "Feature_system_versioning";
Variable_name	Value
Feature_system_versioning	2
drop table t;
#
# MDEV-16991 Rounding vs truncation for TIME, DATETIME, TIMESTAMP
#
SET sql_mode=TIME_ROUND_FRACTIONAL;
SET @@global.system_versioning_asof= timestamp'2001-12-31 23:59:59.9999999';
Warnings:
Note	1292	Truncated incorrect DATETIME value: '2001-12-31 23:59:59.9999999'
SELECT @@global.system_versioning_asof;
@@global.system_versioning_asof
2002-01-01 00:00:00.000000
SET @@global.system_versioning_asof= DEFAULT;