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SET @@session.default_storage_engine = 'MyISAM';
drop table if exists t1;
# Case 1. Partitioning by RANGE based on a non-stored virtual column.
CREATE TABLE t1 (
a DATE NOT NULL,
b int as (year(a))
)
PARTITION BY RANGE( b ) (
PARTITION p0 VALUES LESS THAN (2006),
PARTITION p2 VALUES LESS THAN (2008)
);
insert into t1 values ('2006-01-01',default);
insert into t1 values ('2007-01-01',default);
insert into t1 values ('2005-01-01',default);
insert into t1 (a) values ('2007-01-02');
select * from t1;
a b
2005-01-01 2005
2006-01-01 2006
2007-01-01 2007
2007-01-02 2007
select partition_name,table_rows,data_length from information_schema.partitions where table_name = 't1';
partition_name table_rows data_length
p0 1 7
p2 3 21
# Modify the expression of virtual column b
ALTER TABLE t1 modify b int as (year(a)-1);
select * from t1;
a b
2005-01-01 2004
2006-01-01 2005
2007-01-01 2006
2007-01-02 2006
select partition_name,table_rows,data_length from information_schema.partitions where table_name = 't1';
partition_name table_rows data_length
p0 2 14
p2 2 14
drop table t1;
# Case 2. Partitioning by LIST based on a stored virtual column.
CREATE TABLE t1 (a int, b int as (a % 3 ) persistent)
PARTITION BY LIST (a+1)
(PARTITION p1 VALUES IN (1), PARTITION p2 VALUES IN (2));
insert into t1 values (1,default);
select partition_name,table_rows,data_length from information_schema.partitions where table_name = 't1';
partition_name table_rows data_length
p1 0 0
p2 1 9
select * from t1;
a b
1 1
select * from t1;
a b
1 1
drop table t1;
# Case 3. Partitioning by HASH based on a non-stored virtual column.
CREATE TABLE t1 (
a DATE NOT NULL,
b int as (year(a))
)
PARTITION BY HASH( b % 3 ) PARTITIONS 3;
insert into t1 values ('2005-01-01',default);
insert into t1 values ('2006-01-01',default);
select * from t1;
a b
2005-01-01 2005
2006-01-01 2006
select partition_name,table_rows,data_length from information_schema.partitions where table_name = 't1';
partition_name table_rows data_length
p0 0 0
p1 1 7
p2 1 7
# Modify the expression of virtual column b
ALTER TABLE t1 modify b int as (year(a)-1);
select * from t1;
a b
2005-01-01 2004
2006-01-01 2005
select partition_name,table_rows,data_length from information_schema.partitions where table_name = 't1';
partition_name table_rows data_length
p0 1 7
p1 1 7
p2 0 0
drop table t1;
create table t1 (a int, b datetime as (now())) partition by hash(b+1) partitions 3;
ERROR HY000: Constant, random or timezone-dependent expressions in (sub)partitioning function are not allowed
create table t1 (a int, b varchar(100) as (user())) partition by hash(b+1) partitions 3;
ERROR HY000: Constant, random or timezone-dependent expressions in (sub)partitioning function are not allowed
create table t1 (a int, b double as (rand())) partition by hash(b+1) partitions 3;
ERROR HY000: Constant, random or timezone-dependent expressions in (sub)partitioning function are not allowed
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