TABLE_SNAPSHOTS view
The INFORMATION_SCHEMA.TABLE_SNAPSHOTS
view contains metadata about your
table snapshots. For more information, see Introduction to table
snapshots.
Required permissions
To query the INFORMATION_SCHEMA.TABLE_SNAPSHOTS
view, you need the
bigquery.tables.list
Identity and Access Management (IAM) permission for the dataset.
The roles/bigquery.metadataViewer
predefined role includes the required
permission.
For more information about BigQuery permissions, see Access control with IAM.
Schema
When you query the INFORMATION_SCHEMA.TABLE_SNAPSHOTS
table, the results
contain one row for each table snapshot in the specified dataset or region.
The INFORMATION_SCHEMA.TABLE_SNAPSHOTS
table has the following schema.
The standard table that the
table snapshot was taken from is called the base table.
Column name | Data type | Value |
---|---|---|
table_catalog |
STRING |
The name of the project that contains the table snapshot |
table_schema |
STRING |
The name of the dataset that contains the table snapshot |
table_name |
STRING |
The name of the table snapshot |
base_table_catalog |
STRING |
The name of the project that contains the base table |
base_table_schema |
STRING |
The name of the dataset that contains the base table |
base_table_name |
STRING |
The name of the base table |
snapshot_time |
TIMESTAMP |
The time that the table snapshot was created |
Scope and syntax
Queries against this view must include a dataset or a region qualifier. For queries with a dataset qualifier, you must have permissions for the dataset. For queries with a region qualifier, you must have permissions for the project. For more information see Syntax. The following table explains the region and resource scopes for this view:
View name | Resource scope | Region scope |
---|---|---|
[`PROJECT_ID`.]`region-REGION`.INFORMATION_SCHEMA.TABLE_SNAPSHOTS |
Project level | REGION |
[`PROJECT_ID`.]DATASET_ID.INFORMATION_SCHEMA.TABLE_SNAPSHOTS |
Dataset level | Dataset location |
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`
.DATASET_ID
: the ID of your dataset. For more information, see Dataset qualifier.
Example
-- Returns metadata for the table snapshots in the specified dataset.
SELECT * FROM myDataset.INFORMATION_SCHEMA.TABLE_SNAPSHOTS;
-- Returns metadata for the table snapshots in the specified region.
SELECT * FROM `region-us`.INFORMATION_SCHEMA.TABLE_SNAPSHOTS;
Example
The following query retrieves metadata for the table snapshots in the mydataset
dataset. In this example, it displays the table snapshot
myproject.mydataset.mytablesnapshot
,
which was taken from the base table myproject.mydataset.mytable
on May 14,
2021, at 12 PM UTC.
SELECT * FROM `myproject`.mydataset.INFORMATION_SCHEMA.TABLE_SNAPSHOTS;
The result is similar to the following:
+----------------+---------------+-----------------+--------------------+-------------------+-----------------+-----------------------------+ | table_catalog | table_schema | table_name | base_table_catalog | base_table_schema | base_table_name | snapshot_time | +----------------+---------------+-----------------+----------------------------------------------------------------------------------------+ | myproject | mydataset | mytablesnapshot | myProject | mydataset | mytable | 2021-05-14 12:00:00.000 UTC | +----------------+---------------+-----------------+--------------------+-------------------+-----------------+-----------------------------+