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Задокументировал information_schema.
2.7 KiB
2.7 KiB
system.databases
Contains information about the databases that are available to the current user.
Columns:
name
(String) — Database name.engine
(String) — Database engine.data_path
(String) — Data path.metadata_path
(String) — Metadata path.uuid
(UUID) — Database UUID.comment
(String) — Database comment.
The name
column from this system table is used for implementing the SHOW DATABASES
query.
Example
Create a database.
CREATE DATABASE test;
Check all of the available databases to the user.
SELECT * FROM system.databases;
┌─name───────────────┬─engine─┬─data_path──────────────────┬─metadata_path───────────────────────────────────────────────────────┬─uuid─────────────────────────────────┬─comment─┐
│ INFORMATION_SCHEMA │ 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/ │ 24363899-31d7-42a0-a436-389931d752a0 │ │
│ information_schema │ Memory │ /var/lib/clickhouse/ │ │ 00000000-0000-0000-0000-000000000000 │ │
│ system │ Atomic │ /var/lib/clickhouse/store/ │ /var/lib/clickhouse/store/1d1/1d1c869d-e465-4b1b-a51f-be033436ebf9/ │ 03e9f3d1-cc88-4a49-83e9-f3d1cc881a49 │ │
└────────────────────┴────────┴────────────────────────────┴─────────────────────────────────────────────────────────────────────┴──────────────────────────────────────┴─────────┘