Update column info for system.database

Signed-off-by: Matthew Peveler <matt.peveler@popsql.com>
This commit is contained in:
Matthew Peveler 2020-12-01 21:36:08 +02:00 committed by GitHub
parent 6333570c1e
commit a10222b5fe
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

View File

@ -1,9 +1,38 @@
# system.databases {#system-databases}
This table contains a single String column called name the name of a database.
Contains information about database. Each database that the server knows about has a corresponding entry in the table.
Each database that the server knows about has a corresponding entry in the table.
Columns:
This system table is used for implementing the `SHOW DATABASES` query.
- `name` ([String](../../sql-reference/data-types/string.md)) — Database name.
- `engine` ([String](../../sql-reference/data-types/string.md)) — [Database engine](../..//engines/database-engines/index.md).
- `data_path` ([String](../../sql-reference/data-types/string.md)) — Data path.
- `metadata_path` ([String](../../sql-reference/data-types/enum.md)) — Metadata path.
- `uuid` ([UUID](../../sql-reference/data-types/uuid.md)) — Database UUID.
The `name` column from this system table is used for implementing the `SHOW DATABASES` query.
**Example**
Create a database.
``` sql
CREATE DATABASE test
```
Check all of the available databases.
``` sql
SELECT * FROM system.databases
```
``` text
┌─name───────────────────────────┬─engine─┬─data_path──────────────────┬─metadata_path───────────────────────────────────────────────────────┬─────────────────────────────────uuid─┐
│ _temporary_and_external_tables │ Memory │ /var/lib/clickhouse/ │ │ 00000000-0000-0000-0000-000000000000 │
│ default │ Atomic │ /var/lib/clickhouse/store/ │ /var/lib/clickhouse/store/d31/d317b4bd-3595-4386-81ee-c2334694128a/ │ d317b4bd-3595-4386-81ee-c2334694128a │
│ test │ Atomic │ /var/lib/clickhouse/store/ │ /var/lib/clickhouse/store/39b/39bf0cc5-4c06-4717-87fe-c75ff3bd8ebb/ │ 39bf0cc5-4c06-4717-87fe-c75ff3bd8ebb │
│ system │ Atomic │ /var/lib/clickhouse/store/ │ /var/lib/clickhouse/store/1d1/1d1c869d-e465-4b1b-a51f-be033436ebf9/ │ 1d1c869d-e465-4b1b-a51f-be033436ebf9 │
└────────────────────────────────┴────────┴────────────────────────────┴─────────────────────────────────────────────────────────────────────┴──────────────────────────────────────┘
```
[Original article](https://clickhouse.tech/docs/en/operations/system_tables/databases) <!--hide-->