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create table emp
(
emp_id int,
name varchar(127),
mgr int
) with system versioning;
insert into emp values (1, 'bill', 0),
(2, 'bill', 1),
(3, 'kate', 1);
set @ts=now(6);
delete from emp;
insert into emp values (4, 'john', 1);
with ancestors as (select * from emp) select * from ancestors;
emp_id name mgr
4 john 1
set @tmp= "with ancestors as (select * from emp) select * from ancestors";
prepare stmt from @tmp;
execute stmt;
emp_id name mgr
4 john 1
drop prepare stmt;
with ancestors as (select * from emp for system_time all) select * from ancestors;
emp_id name mgr
1 bill 0
2 bill 1
3 kate 1
4 john 1
set @tmp= "with ancestors as (select * from emp for system_time all) select * from ancestors";
prepare stmt from @tmp;
execute stmt;
emp_id name mgr
1 bill 0
2 bill 1
3 kate 1
4 john 1
drop prepare stmt;
with recursive ancestors as (select * from emp) select * from ancestors;
emp_id name mgr
4 john 1
set @tmp= "with recursive ancestors as (select * from emp) select * from ancestors";
prepare stmt from @tmp;
execute stmt;
emp_id name mgr
4 john 1
drop prepare stmt;
select emp_id from (select emp_id from emp where row_end>'2031-1-1') as tmp;
emp_id
4
set @tmp= "select emp_id from (select emp_id from emp where row_end>'2031-1-1') as tmp";
prepare stmt from @tmp;
execute stmt;
emp_id
4
drop prepare stmt;
with recursive
ancestors
as
(
select e.emp_id, e.name, e.mgr
from emp as e
where name = 'john'
union
select ee.emp_id, ee.name, ee.mgr
from emp as ee, ancestors as a
where ee.mgr = a.emp_id
)
select * from ancestors;
emp_id name mgr
4 john 1
set @tmp= "
with recursive
ancestors
as
(
select e.emp_id, e.name, e.mgr
from emp as e
where name = 'john'
union
select ee.emp_id, ee.name, ee.mgr
from emp as ee, ancestors as a
where ee.mgr = a.emp_id
)
select * from ancestors";
prepare stmt from @tmp;
execute stmt;
emp_id name mgr
4 john 1
drop prepare stmt;
with recursive
ancestors
as
(
select e.emp_id, e.name, e.mgr
from emp for system_time as of timestamp @ts as e
where name = 'bill'
union
select ee.emp_id, ee.name, ee.mgr
from emp for system_time as of timestamp @ts as ee,
ancestors as a
where ee.mgr = a.emp_id
)
select * from ancestors;
emp_id name mgr
1 bill 0
2 bill 1
3 kate 1
set @tmp= "
with recursive
ancestors
as
(
select e.emp_id, e.name, e.mgr
from emp for system_time as of timestamp @ts as e
where name = 'bill'
union
select ee.emp_id, ee.name, ee.mgr
from emp for system_time as of timestamp @ts as ee,
ancestors as a
where ee.mgr = a.emp_id
)
select * from ancestors";
prepare stmt from @tmp;
execute stmt;
emp_id name mgr
1 bill 0
2 bill 1
3 kate 1
drop prepare stmt;
drop table emp;
create or replace table t1 (x int) with system versioning;
create or replace table t2 (y int) with system versioning;
insert into t1 values (1);
set @t0= now(6);
delete from t1;
insert into t1 values (2);
insert into t2 values (10);
select * from (select *, t1.row_end, t1.row_end as endo from t1) as s0;
x row_end endo
2 # #
select * from (select *, t1.row_end, t2.row_start from t1, t2) as s0;
x y row_end row_start
2 10 # #
# SYSTEM_TIME propagation from inner to outer
select * from (select * from t1 for system_time as of timestamp @t0, t2) as s0;
x y
1 10
with s1 as (select * from t1 for system_time as of timestamp @t0, t2) select * from s1;
x y
1 10
# leading table selection
select * from (select *, t1.row_end from t2, t1 for system_time as of timestamp @t0) as s2;
y x row_end
10 1 #
with s3 as (select *, t1.row_end from t2, t1 for system_time as of timestamp @t0) select * from s3;
y x row_end
10 1 #
### VIEW instead of t1
set @q= concat("create view vt1 as select * from t1 for system_time as of timestamp '", @t0, "'");
prepare q from @q;
execute q;
drop prepare q;
create view vt2 as select * from t1;
# SYSTEM_TIME propagation from view
select * from vt1;
x
1
# SYSTEM_TIME propagation from inner to outer
select * from (select * from vt1, t2) as s0;
x y
1 10
### SYSTEM_TIME clash
select * from (select * from t1 for system_time all) for system_time all as dt0;
ERROR HY000: Table `dt0` is not system-versioned
select * from vt1 for system_time all;
ERROR HY000: Table `vt1` is not system-versioned
with dt1 as (select * from t1 for system_time all)
select * from dt1 for system_time all;
ERROR HY000: Table `dt1` is not system-versioned
### UNION
set @t1= now(6);
delete from t2;
insert into t2 values (3);
# SYSTEM_TIME is not propagated
select x from t1 union
select y from t2;
x
2
3
select x from t1 for system_time as of @t0 union
select y from t2;
x
1
3
select x from t1 union
select y from t2 for system_time as of @t1;
x
2
10
select x from t1 for system_time as of @t0 union
select y from t2 for system_time as of @t1;
x
1
10
# LEFT/RIGHT JOIN
create or replace table t1 (x int, y int) with system versioning;
create or replace table t2 (x int, y int) with system versioning;
insert into t1 values (1, 1), (1, 2), (1, 3), (4, 4), (5, 5);
insert into t2 values (1, 2), (2, 1), (3, 1);
## Outer or inner SYSTEM_TIME produces same expression
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 100.00 Using where
1 SIMPLE t1 ALL NULL NULL NULL NULL 5 100.00 Using where; Using join buffer (flat, BNL join)
Query A:
Note 1003 select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t2`.`row_start` <= <cache>(current_timestamp(6)) and `test`.`t1`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t1`.`row_start` <= <cache>(current_timestamp(6))
id select_type table type possible_keys key key_len ref rows filtered Extra
1 SIMPLE t2 ALL NULL NULL NULL NULL 3 100.00 Using where
1 SIMPLE t1 ALL NULL NULL NULL NULL 5 100.00 Using where; Using join buffer (flat, BNL join)
Query B:
Note 1003 select `test`.`t1`.`x` AS `x`,`test`.`t1`.`y` AS `y1`,`test`.`t2`.`x` AS `x2`,`test`.`t2`.`y` AS `y2` from `test`.`t1` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) join `test`.`t2` FOR SYSTEM_TIME AS OF TIMESTAMP current_timestamp(6) where `test`.`t1`.`x` = `test`.`t2`.`x` and `test`.`t2`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t2`.`row_start` <= <cache>(current_timestamp(6)) and `test`.`t1`.`row_end` > <cache>(current_timestamp(6)) and `test`.`t1`.`row_start` <= <cache>(current_timestamp(6))
Fine result: queries A and B are equal.
## LEFT JOIN: t1, t2 versioned
select * from (
select t1.x as LJ1_x1, t1.y as y1, t2.x as x2, t2.y as y2
from t1 left join t2 on t1.x = t2.x)
as derived;
LJ1_x1 y1 x2 y2
1 1 1 2
1 2 1 2
1 3 1 2
4 4 NULL NULL
5 5 NULL NULL
alter table t2 drop system versioning;
## LEFT JOIN: t1 versioned
select * from (
select t1.x as LJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2
from t1 left join t2 on t1.x = t2.x)
as derived;
LJ2_x1 y1 x2 y2
1 1 1 2
1 2 1 2
1 3 1 2
4 4 NULL NULL
5 5 NULL NULL
alter table t1 drop system versioning;
alter table t2 add system versioning;
## LEFT JOIN: t2 versioned
select * from (
select t1.x as LJ3_x1, t1.y as y1, t2.x as x2, t2.y as y2
from t1 left join t2 on t1.x = t2.x)
as derived;
LJ3_x1 y1 x2 y2
1 1 1 2
1 2 1 2
1 3 1 2
4 4 NULL NULL
5 5 NULL NULL
alter table t1 add system versioning;
## RIGHT JOIN: t1, t2 versioned
select * from (
select t1.x as RJ1_x1, t1.y as y1, t2.x as x2, t2.y as y2
from t1 right join t2 on t1.x = t2.x)
as derived;
RJ1_x1 y1 x2 y2
1 1 1 2
1 2 1 2
1 3 1 2
NULL NULL 2 1
NULL NULL 3 1
alter table t2 drop system versioning;
## RIGHT JOIN: t1 versioned
select * from (
select t1.x as RJ2_x1, t1.y as y1, t2.x as x2, t2.y as y2
from t1 right join t2 on t1.x = t2.x)
as derived;
RJ2_x1 y1 x2 y2
1 1 1 2
1 2 1 2
1 3 1 2
NULL NULL 2 1
NULL NULL 3 1
alter table t1 drop system versioning;
alter table t2 add system versioning;
## RIGHT JOIN: t2 versioned
select * from (
select t1.x as RJ3_x1, t1.y as y1, t2.x as x2, t2.y as y2
from t1 right join t2 on t1.x = t2.x)
as derived;
RJ3_x1 y1 x2 y2
1 1 1 2
1 2 1 2
1 3 1 2
NULL NULL 2 1
NULL NULL 3 1
drop table t1, t2;
drop view vt1, vt2;
|
