SCHEMATA view
The INFORMATION_SCHEMA.SCHEMATA
view provides information about the datasets
in a project or region. The view returns one row for each dataset.
Before you begin
To query the SCHEMATA
view for dataset metadata, you need the bigquery.datasets.get
Identity and Access Management (IAM) permission at the project level.
Each of the following predefined IAM roles includes the
permissions that you need in order to get the SCHEMATA
view:
roles/bigquery.admin
roles/bigquery.dataEditor
roles/bigquery.dataOwner
roles/bigquery.dataViewer
For more information about BigQuery permissions, see Access control with IAM.
Schema
When you query theINFORMATION_SCHEMA.SCHEMATA
view, the query results contain
one row for each dataset in the specified project.
The INFORMATION_SCHEMA.SCHEMATA
view has the following schema:
Column name | Data type | Value |
---|---|---|
CATALOG_NAME |
STRING |
The name of the project that contains the dataset |
SCHEMA_NAME |
STRING |
The dataset's name also referred to as the datasetId |
SCHEMA_OWNER |
STRING |
The value is always NULL |
CREATION_TIME |
TIMESTAMP |
The dataset's creation time |
LAST_MODIFIED_TIME |
TIMESTAMP |
The dataset's last modified time |
LOCATION |
STRING |
The dataset's geographic location |
DDL |
STRING |
The CREATE SCHEMA
DDL statement that can be used to create the dataset |
DEFAULT_COLLATION_NAME |
STRING |
The name of the default collation specification
if it exists; otherwise, NULL .
|
Scope and syntax
Queries against this view must include a region qualifier. If you do not specify a regional qualifier, metadata is retrieved from the US region. The following table explains the region scope for this view:
View Name | Resource scope | Region scope |
---|---|---|
[PROJECT_ID.]INFORMATION_SCHEMA.SCHEMATA |
Project level | US region |
[PROJECT_ID.]`region-REGION`.INFORMATION_SCHEMA.SCHEMATA |
Project level | REGION |
- Optional:
PROJECT_ID
: the ID of your Google Cloud project. If not specified, the default project is used.
REGION
: any dataset region name. For example,`region-us`
.
Example
-- Returns metadata for datasets in a region.
SELECT * FROM region-us.INFORMATION_SCHEMA.SCHEMATA;
Example
To run the query against a project other than your default project, add the project ID to the dataset in the following format:
`PROJECT_ID`.INFORMATION_SCHEMA.SCHEMATA
`myproject`.INFORMATION_SCHEMA.SCHEMATA
.
SELECT * EXCEPT (schema_owner) FROM INFORMATION_SCHEMA.SCHEMATA;
The result is similar to the following. For readability, some columns are excluded from the result.
+----------------+---------------+---------------------+---------------------+------------+------------------------------------------+ | catalog_name | schema_name | creation_time | last_modified_time | location | ddl | +----------------+---------------+---------------------+---------------------+------------+------------------------------------------+ | myproject | mydataset1 | 2018-11-07 19:50:24 | 2018-11-07 19:50:24 | US | CREATE SCHEMA `myproject.mydataset1` | | | | | | | OPTIONS( | | | | | | | location="us" | | | | | | | ); | +----------------+---------------+---------------------+---------------------+------------+------------------------------------------+ | myproject | mydataset2 | 2018-07-16 04:24:22 | 2018-07-16 04:24:22 | US | CREATE SCHEMA `myproject.mydataset2` | | | | | | | OPTIONS( | | | | | | | default_partition_expiration_days=3.0, | | | | | | | location="us" | | | | | | | ); | +----------------+---------------+---------------------+---------------------+------------+------------------------------------------+ | myproject | mydataset3 | 2018-02-07 21:08:45 | 2018-05-01 23:32:53 | US | CREATE SCHEMA `myproject.mydataset3` | | | | | | | OPTIONS( | | | | | | | description="My dataset", | | | | | | | location="us" | | | | | | | ); | +----------------+---------------+---------------------+---------------------+------------+------------------------------------------+