The following cases are unstable.
1. LoadStreamMgrTest
2. TaskWorkerPoolTest.PriorTaskWorkerPool
Rationales
1. LoadStreamMgrTest
It is related to timeout. If we investigate the examples in BRPC, we will find the timeout is usually set to 0 rather than a specific number.
2. TaskWorkerPoolTest.PriorTaskWorkerPool
The order of the threads for the lock contentions is undetermined.
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
