Klustron 1.3.1 release notes

1.3.1 新增语法如下：

1、新增兼容mysql的show命令

SHOW CREATE DATABASE db_name;
SHOW CREATE SCHEMA schema_name;
SHOW INDEX IN table_name [ WHERE expr ];

例如:

mysql> show index in t1;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| table | non_unique | key_name | seq_in_index | column_name | collation | cardinality | sub_part | packed | null | index_type | comment | index_comment | visible | expression |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
| t1    | 1          | t1_a_idx | 1            | a           | A         | 0           | NULL     | NULL   | YES  | BTREE      |         |               | YES     | NULL       |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------+------------+---------+---------------+---------+------------+
1 row in set (0.00 sec)

2、生成列

create table t1(a int,
	b int generated always as (a+1) virtual,
	c int generated always as (a+2) stored);

3、序列新增属性cache_method。用来控制cache size是否根据负载动态变化

CREATE [ TEMPORARY | TEMP ] SEQUENCE [ IF NOT EXISTS ] name
    [ AS data_type ]
    [ INCREMENT [ BY ] increment ]
    [ MINVALUE minvalue | NO MINVALUE | NOMINVALUE ] [ MAXVALUE maxvalue | NO MAXVALUE | NOMAXVALUE ]
    [ { START | STARTS } [ WITH ] start ] [ NOCACHE | CACHE cache ] [ [ NO ] CYCLE | NOCYCLE ] [CACHE METHOD cache_method]
    [ ORDER | NOORDER ] [ SHARD  shard ]
    [ OWNED BY { table_name.column_name | NONE } ]

where cache_method can be one of:
    'STATIC'
    'DYNAMIC'

4、支持EXPLAIN的别名DESC、DESCRIBE。例如：

mysql> desc select * From t1;
+----------------------------------------------------------------+
| QUERY PLAN                                                     |
+----------------------------------------------------------------+
| RemotePlan  (cost=101.02..101.02 rows=1 width=4)               |
|   Shard: 1    Remote SQL: SELECT t1.a FROM  `abc_$$_public`.`t1`  |
+----------------------------------------------------------------+
2 rows in set (0.00 sec)

5、支持"DESC table_name"查看表结构:

mysql> desc t1;
+-------+---------+------+------+---------+-------+
| field | type    | null | key  | default | extra |
+-------+---------+------+------+---------+-------+
| a     | integer | YES  |      | NULL    |       |
+-------+---------+------+------+---------+-------+
1 row in set (0.00 sec)

END