DescribeQueryExplain-阿里云帮助中心

Obtain the execution plan for an SQL statement.

Operation description

This operation supports only ApsaraDB RDS for MySQL and PolarDB for MySQL instances.
When using the Alibaba Cloud or DAS SDK, use the latest version.
When calling the DAS service with the SDK, set the region to cn-shanghai.

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Test

RAM authorization

The table below describes the authorization required to call this API. You can define it in a Resource Access Management (RAM) policy. The table's columns are detailed below:

Action: The actions can be used in the Action element of RAM permission policy statements to grant permissions to perform the operation.
API: The API that you can call to perform the action.
Access level: The predefined level of access granted for each API. Valid values: create, list, get, update, and delete.
Resource type: The type of the resource that supports authorization to perform the action. It indicates if the action supports resource-level permission. The specified resource must be compatible with the action. Otherwise, the policy will be ineffective.
- For APIs with resource-level permissions, required resource types are marked with an asterisk (*). Specify the corresponding Alibaba Cloud Resource Name (ARN) in the Resource element of the policy.
- For APIs without resource-level permissions, it is shown as All Resources. Use an asterisk (*) in the Resource element of the policy.
Condition key: The condition keys defined by the service. The key allows for granular control, applying to either actions alone or actions associated with specific resources. In addition to service-specific condition keys, Alibaba Cloud provides a set of common condition keys applicable across all RAM-supported services.
Dependent action: The dependent actions required to run the action. To complete the action, the RAM user or the RAM role must have the permissions to perform all dependent actions.

Action

Access level

Resource type

Condition key

Dependent action

hdm:DescribeQueryExplain

get

*All Resource

*

None

Request syntax

POST  HTTP/1.1

Request parameters

Parameter	Type	Required	Description	Example
InstanceId	string	Yes	The ID of the instance.	rm-2ze8g2am97624****
NodeId	string	No	The ID of the node. Note For PolarDB for MySQL instances, if you specify a node ID, the system queries the execution plan on that node. Otherwise, it queries the execution plan on a secondary node.For high availability ApsaraDB RDS for MySQL instances, if you specify an instance ID, the system queries the execution plan on that node. Otherwise, it queries the execution plan on a secondary node.	pi-bp1v203xzzh0a****
Sql	string	Yes	The SQL statement for which you want to get the execution plan.	select * from test where name = 'mockUser'
DbName	string	No	The name of the database.	dbtest01
Schema	string	No	Schema information. This is a reserved parameter.	无

Response elements

Element	Type	Description	Example
	object	Response schema
Code	string	The status code returned. A value of 200 indicates success.	200
Message	string	The response message. Note If the request succeeds, this parameter returns Successful. If the request fails, this parameter returns error details such as an error code.	Successful
RequestId	string	The ID of the request.	B6D17591-B48B-4D31-9CD6-9B9796B2****
Success	string	Indicates whether the request succeeded: true: The request succeeded. false: The request failed.	true
Data	array<object>	List of execution plans.
	object	The returned data.
Id	string	The ID of the query.	1
SelectType	string	The type of the query.	SIMPLE
Table	string	The name of the table.	test
Type	string	The join type.	eq_ref
PossibleKeys	string	The indexes that might be used.	test_idx
Key	string	The index actually used in the execution plan.	PRIMARY
KeyLen	string	The length of the index actually used.	3
Ref	string	The column used by the index.	test_column
Rows	string	The number of rows to scan.	1000
Extra	string	Additional information.	无
QueryPlan	string	A reserved field for the PostgreSQL engine.	无
TableList	array	A reserved field for the PostgreSQL engine.
	string	A reserved field for the PostgreSQL engine.	无
IndexList	array	A reserved field for the PostgreSQL engine.
	string	A reserved field for the PostgreSQL engine.	无
LogicalPlanList	array	A reserved field for the PolarDB X engine.
	string	A reserved field for the PolarDB X engine.	无
StmtText	string	A reserved field for the SQL Server engine.	无
StmtId	string	A reserved field for the SQL Server engine.	无
NodeId	string	A reserved field for the SQL Server engine.	无
Parent	string	A reserved field for the SQL Server engine.	无
PhysicalOp	string	A reserved field for the SQL Server engine.	无
LogicalOp	string	A reserved field for the SQL Server engine.	无
Argument	string	A reserved field for the SQL Server engine.	无
DefinedValues	string	A reserved field for the SQL Server engine.	无
EstimateRows	string	A reserved field for the SQL Server engine.	无
EstimateIO	string	A reserved field for the SQL Server engine.	无
EstimateCPU	string	A reserved field for the SQL Server engine.	无
AvgRowSize	string	A reserved field for the SQL Server engine.	无
TotalSubtreeCost	string	A reserved field for the SQL Server engine.	无
OutputList	string	A reserved field for the SQL Server engine.	无
Warnings	string	A reserved field for the SQL Server engine.	无
Parallel	string	A reserved field for the SQL Server engine.	无
EstimateExecutions	string	A reserved field for the SQL Server engine.	无

Examples

Success response

JSON format

{
  "Code": "200",
  "Message": "Successful",
  "RequestId": "B6D17591-B48B-4D31-9CD6-9B9796B2****",
  "Success": "true",
  "Data": [
    {
      "Id": "1",
      "SelectType": "SIMPLE",
      "Table": "test",
      "Type": "eq_ref",
      "PossibleKeys": "test_idx",
      "Key": "PRIMARY",
      "KeyLen": "3",
      "Ref": "test_column",
      "Rows": "1000",
      "Extra": "无",
      "QueryPlan": "无",
      "TableList": [
        "无"
      ],
      "IndexList": [
        "无"
      ],
      "LogicalPlanList": [
        "无"
      ],
      "StmtText": "无",
      "StmtId": "无",
      "NodeId": "无",
      "Parent": "无",
      "PhysicalOp": "无",
      "LogicalOp": "无",
      "Argument": "无",
      "DefinedValues": "无",
      "EstimateRows": "无",
      "EstimateIO": "无",
      "EstimateCPU": "无",
      "AvgRowSize": "无",
      "TotalSubtreeCost": "无",
      "OutputList": "无",
      "Warnings": "无",
      "Parallel": "无",
      "EstimateExecutions": "无"
    }
  ]
}

Error codes

HTTP status code	Error code	Error message	Description
400	InvalidParams	The request parameters are invalid.

See Error Codes for a complete list.

Release notes

See Release Notes for a complete list.