ExecuteGremlinExplainQuery
Executes a Gremlin Explain query.
Amazon Neptune has added a Gremlin feature named explain
that provides is a self-service tool for understanding the execution
approach being taken by the Neptune engine for the query. You invoke
it by adding an explain
parameter to an HTTP call that
submits a Gremlin query.
The explain feature provides information about the logical structure of query execution plans. You can use this information to identify potential evaluation and execution bottlenecks and to tune your query, as explained in Tuning Gremlin queries. You can also use query hints to improve query execution plans.
When invoking this operation in a Neptune cluster that has IAM authentication enabled, the IAM user or role making the request must have a policy attached that allows one of the following IAM actions in that cluster, depending on the query:
Note that the neptune-db:QueryLanguage:Gremlin IAM condition key can be used in the policy document to restrict the use of Gremlin queries (see Condition keys available in Neptune IAM data-access policy statements).
Request Syntax
POST /gremlin/explain HTTP/1.1
Content-type: application/json
{
"gremlin": "string
"
}
URI Request Parameters
The request does not use any URI parameters.
Request Body
The request accepts the following data in JSON format.
- gremlin
-
The Gremlin explain query string.
Type: String
Required: Yes
Response Syntax
HTTP/1.1 200
output
Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The response returns the following as the HTTP body.
- output
-
A text blob containing the Gremlin explain result, as described in Tuning Gremlin queries.
Errors
For information about the errors that are common to all actions, see Common Errors.
- BadRequestException
-
Raised when a request is submitted that cannot be processed.
HTTP Status Code: 400
- CancelledByUserException
-
Raised when a user cancelled a request.
HTTP Status Code: 500
- ClientTimeoutException
-
Raised when a request timed out in the client.
HTTP Status Code: 408
- ConcurrentModificationException
-
Raised when a request attempts to modify data that is concurrently being modified by another process.
HTTP Status Code: 500
- ConstraintViolationException
-
Raised when a value in a request field did not satisfy required constraints.
HTTP Status Code: 400
- FailureByQueryException
-
Raised when a request fails.
HTTP Status Code: 500
- IllegalArgumentException
-
Raised when an argument in a request is not supported.
HTTP Status Code: 400
- InvalidArgumentException
-
Raised when an argument in a request has an invalid value.
HTTP Status Code: 400
- InvalidParameterException
-
Raised when a parameter value is not valid.
HTTP Status Code: 400
- MalformedQueryException
-
Raised when a query is submitted that is syntactically incorrect or does not pass additional validation.
HTTP Status Code: 400
- MemoryLimitExceededException
-
Raised when a request fails because of insufficient memory resources. The request can be retried.
HTTP Status Code: 500
- MissingParameterException
-
Raised when a required parameter is missing.
HTTP Status Code: 400
- ParsingException
-
Raised when a parsing issue is encountered.
HTTP Status Code: 400
- PreconditionsFailedException
-
Raised when a precondition for processing a request is not satisfied.
HTTP Status Code: 400
- QueryLimitExceededException
-
Raised when the number of active queries exceeds what the server can process. The query in question can be retried when the system is less busy.
HTTP Status Code: 500
- QueryLimitException
-
Raised when the size of a query exceeds the system limit.
HTTP Status Code: 400
- QueryTooLargeException
-
Raised when the body of a query is too large.
HTTP Status Code: 400
- TimeLimitExceededException
-
Raised when the an operation exceeds the time limit allowed for it.
HTTP Status Code: 500
- TooManyRequestsException
-
Raised when the number of requests being processed exceeds the limit.
HTTP Status Code: 429
- UnsupportedOperationException
-
Raised when a request attempts to initiate an operation that is not supported.
HTTP Status Code: 400
See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following: