Add `information_schema` database for all catalog.
This is useful when using BI tools to connect to Doris,
the tools can get meta info from `information_schema`.
This PR mainly changes:
1. There will be a `information_schema` db in each catalog.
2. Each `information_schema` db only store the meta info of the catalog it belongs to.
3. For `information_schema`, the `TABLE_SCHEMA` column's value is the database name.
4. There is a new global variable `show_full_dbname_in_info_schema_db`, default is false, if set to true,
The `TABLE_SCHEMA` column's value is the like `ctl.db`, because:
When connect to Doris, the `database` info in connection url will be: `xxx?db=ctl.db`.
And then some BI will try to query `information_schema` with sql like:
`select * from information_schema.columns where TABLE_SCHEMA = "ctl.db"`
So it has to be format as `ctl.db`
eg, the `information_schema.columns` table in external catalog `doris` is like:
```
mysql> select * from information_schema.columns limit 1\G
*************************** 1. row ***************************
TABLE_CATALOG: doris
TABLE_SCHEMA: doris.__internal_schema
TABLE_NAME: column_statistics
COLUMN_NAME: id
ORDINAL_POSITION: 1
COLUMN_DEFAULT: NULL
IS_NULLABLE: NO
DATA_TYPE: varchar
CHARACTER_MAXIMUM_LENGTH: 4096
CHARACTER_OCTET_LENGTH: 16384
NUMERIC_PRECISION: NULL
NUMERIC_SCALE: NULL
DATETIME_PRECISION: NULL
CHARACTER_SET_NAME: NULL
COLLATION_NAME: NULL
COLUMN_TYPE: varchar(4096)
COLUMN_KEY:
EXTRA:
PRIVILEGES:
COLUMN_COMMENT:
COLUMN_SIZE: 4096
DECIMAL_DIGITS: NULL
GENERATION_EXPRESSION: NULL
SRS_ID: NULL
```
6. Modify the behavior of
- show tables
- shwo databases
- show columns
- show table status
The above statements may query the `information_schema` db if there is `where` predicate after them
新加case注意事项
-
变量名前要写 def,否则是全局变量,并行跑的 case 的时候可能被其他 case 影响。
Problematic code:
ret = ***Correct code:
def ret = *** -
尽量不要在 case 中 global 的设置 session variable,或者修改集群配置,可能会影响其他 case。
Problematic code:
sql """set global enable_pipeline_x_engine=true;"""Correct code:
sql """set enable_pipeline_x_engine=true;""" -
如果必须要设置 global,或者要改集群配置,可以指定 case 以 nonConcurrent 的方式运行。
-
case 中涉及时间相关的,最好固定时间,不要用类似 now() 函数这种动态值,避免过一段时间后 case 就跑不过了。
Problematic code:
sql """select count(*) from table where created < now();"""Correct code:
sql """select count(*) from table where created < '2023-11-13';""" -
case 中 streamload 后请加上 sync 一下,避免在多 FE 环境中执行不稳定。
Problematic code:
streamLoad { ... } sql """select count(*) from table """Correct code:
streamLoad { ... } sql """sync""" sql """select count(*) from table """