DescribeDBInstanceDataSkew - AnalyticDB - Alibaba Cloud Documentation Center

Queries the information about data skew for an AnalyticDB for PostgreSQL instance.

Operation description

To prevent data skew from affecting your database service, you can call this operation to query the details about data skew on an AnalyticDB for PostgreSQL instance.

Limits

You can call this operation up to 1,000 times per second per account. If the number of the calls per second exceeds the limit, throttling is triggered. As a result, your business may be affected. We recommend that you take note of the limit when you call this operation.

Debugging

You can run this interface directly in OpenAPI Explorer, saving you the trouble of calculating signatures. After running successfully, OpenAPI Explorer can automatically generate SDK code samples.

Debug

Authorization information

The following table shows the authorization information corresponding to the API. The authorization information can be used in the Action policy element to grant a RAM user or RAM role the permissions to call this API operation. Description:

Operation: the value that you can use in the Action element to specify the operation on a resource.
Access level: the access level of each operation. The levels are read, write, and list.
Resource type: the type of the resource on which you can authorize the RAM user or the RAM role to perform the operation. Take note of the following items:
- For mandatory resource types, indicate with a prefix of * .
- If the permissions cannot be granted at the resource level, All Resources is used in the Resource type column of the operation.
Condition Key: the condition key that is defined by the cloud service.
Associated operation: other operations that the RAM user or the RAM role must have permissions to perform to complete the operation. To complete the operation, the RAM user or the RAM role must have the permissions to perform the associated operations.

Operation	Access level	Resource type	Condition key	Associated operation
gpdb:DescribeDBInstanceDataSkew	get	DBInstance `acs:gpdb::{#accountId}:dbinstance/{#DBInstanceId}`	none	none

Request parameters

Parameter	Type	Required	Description	Example
DBInstanceId	string	Yes	The ID of the instance. Note You can call the DescribeDBInstances operation to query the details of all AnalyticDB for PostgreSQL instances in a specific region, including instance IDs.	gp-bp12ga6v69h86****
PageSize	integer	No	The number of entries per page. Valid values: 30 50 100 Default value: 30.	20
PageNumber	integer	No	The number of the page to return. The value must be an integer that is greater than 0. Default value: 1.	1
Database	string	No	The name of the database.	test
OrderBy	string	No	order by condition	{Field: TableSkew, Type: Desc}

Response parameters

Parameter	Type	Description	Example
	object
RequestId	string	The ID of the request.	B4CAF581-2AC7-41AD-8940-D56DF7AADF5B
TotalCount	integer	The total number of entries returned.	100
PageNumber	integer	The page number of the returned page.	1
Items	array<object>	Details about data skew.
Items	object
Sequence	integer	The sequence number of the data skew case. All data skew cases are sorted by severity in descending order.	1
DatabaseName	string	The name of the database.	adbtest
SchemaName	string	The name of the schema.	schema1
TableName	string	The name of the table.	tab1
Owner	string	The owner of the table.	adbpguser
TableSize	string	The total number of rows in the table.	100000
TableSkew	string	The skew ratio of the table. Valid values: 0 to 100. Unit: %. A greater value indicates that the table is more severely skewed. A smaller value indicates less impact on query performance. A value of 0 indicates no data skew.	10.23
DistributeKey	string	The distribution key of the table.	ItemId
TimeLastUpdated	string	The time when the table was last deleted, inserted, or updated.	2020-09-08T20:00:00Z

Examples

Sample success responses

JSONformat

{
  "RequestId": "B4CAF581-2AC7-41AD-8940-D56DF7AADF5B",
  "TotalCount": 100,
  "PageNumber": 1,
  "Items": [
    {
      "Sequence": 1,
      "DatabaseName": "adbtest",
      "SchemaName": "schema1",
      "TableName": "tab1",
      "Owner": "adbpguser",
      "TableSize": 100000,
      "TableSkew": 10.23,
      "DistributeKey": "ItemId",
      "TimeLastUpdated": "2020-09-08T20:00:00Z"
    }
  ]
}

Error codes

For a list of error codes, visit the Service error codes.

Change history

Change time	Summary of changes	Operation
2024-08-06	The request parameters of the API has changed	View Change Details