DescribeQueryExplain - Database Autonomy Service - Alibaba Cloud Documentation Center

Queries the execution plan of an SQL statement.

Operation description

Currently, only RDS MySQL and PolarDB MySQL instances support querying SQL execution plans.
When using Alibaba Cloud or DAS software development kit (SDK), we recommend that you use the latest version.
When you call the DAS service using an SDK, you must specify the region as 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 support 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 instance ID.	rm-2ze8g2am97624****
NodeId	string	No	The node ID. Note For PolarDB MySQL instances, if you provide a node ID, the execution plan will be queried on the specified node. Otherwise, the execution plan will be queried on the read-only node. For RDS MySQL high availability instances, if you provide an instance ID, the execution plan will be queried on the specified node. Otherwise, the execution plan will be queried on the read-only node.	pi-bp1v203xzzh0a****
Sql	string	Yes	The SQL statement for which you want to query the execution plan.	select * from test where name = 'mockUser'
DbName	string	No	The database name.	dbtest01
Schema	string	No	The schema information. This is a reserved parameter.	无

Response parameters

Parameter	Type	Description	Example
	object	Schema of Response
Code	string	The returned status code. A value of 200 indicates that the request was successful.	200
Message	string	The returned message. Note When the request is successful, this parameter returns Successful. When the request fails, this parameter returns exception information, such as an error code.	Successful
RequestId	string	The request ID.	B6D17591-B48B-4D31-9CD6-9B9796B2****
Success	string	Indicates whether the request was successful: true: The request was successful. false: The request failed.	true
Data	array	List
	object	The returned data.
Id	string	The query ID.	1
SelectType	string	The query type.	SIMPLE
Table	string	The table name.	test
Type	string	The join type.	eq_ref
PossibleKeys	string	The possible indexes that can be selected.	test_idx
Key	string	The index that is actually selected in the execution plan.	PRIMARY
KeyLen	string	The length of the index that is actually selected.	3
Ref	string	The columns used by the index.	test_column
Rows	string	The number of rows to be scanned.	1000
Extra	string	Additional information.	无
QueryPlan	string	A reserved field for the PG engine.	无
TableList	array	A reserved field for the PG engine.
	string	A reserved field for the PG engine.	无
IndexList	array	A reserved field for the PG engine.
	string	A reserved field for the PG 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 SQLServer engine.	无
StmtId	string	A reserved field for the SQLServer engine.	无
NodeId	string	A reserved field for the SQLServer engine.	无
Parent	string	A reserved field for the SQLServer engine.	无
PhysicalOp	string	A reserved field for the SQLServer engine.	无
LogicalOp	string	A reserved field for the SQLServer engine.	无
Argument	string	A reserved field for the SQLServer engine.	无
DefinedValues	string	A reserved field for the SQLServer engine.	无
EstimateRows	string	A reserved field for the SQLServer engine.	无
EstimateIO	string	A reserved field for the SQLServer engine.	无
EstimateCPU	string	A reserved field for the SQLServer engine.	无
AvgRowSize	string	A reserved field for the SQLServer engine.	无
TotalSubtreeCost	string	A reserved field for the SQLServer engine.	无
OutputList	string	A reserved field for the SQLServer engine.	无
Warnings	string	A reserved field for the SQLServer engine.	无
Parallel	string	A reserved field for the SQLServer engine.	无
EstimateExecutions	string	A reserved field for the SQLServer 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.