mirror of
https://github.com/hasura/graphql-engine.git
synced 2024-12-21 06:21:39 +03:00
126 lines
3.9 KiB
ReStructuredText
126 lines
3.9 KiB
ReStructuredText
.. meta::
|
|
:description: Hasura explain API reference
|
|
:keywords: hasura, docs, explain API, API reference
|
|
|
|
.. _explain_api_reference:
|
|
|
|
Explain API Reference
|
|
=====================
|
|
|
|
.. contents:: Table of contents
|
|
:backlinks: none
|
|
:depth: 1
|
|
:local:
|
|
|
|
The Explain API is used to analyse queries and subscriptions. It returns a list of Postgres plans for a query and a single Postgres plan for a subscription, based
|
|
on the defined permissions.
|
|
|
|
Endpoint
|
|
--------
|
|
|
|
All requests are ``POST`` requests to the ``/v1/graphql/explain`` endpoint.
|
|
|
|
API Spec
|
|
--------
|
|
|
|
Request
|
|
^^^^^^^
|
|
|
|
The request expects a JSON object with the following keys:
|
|
- ``query``: the GraphQL query to be analysed
|
|
- ``user`` (optional): the ``x-hasura-role`` along with session variables
|
|
|
|
.. code-block:: http
|
|
|
|
POST /v1/graphql/explain HTTP/1.1
|
|
Content-Type: application/json
|
|
|
|
{
|
|
"query": "<query>",
|
|
"user": {
|
|
"x-hasura-role" : "...",
|
|
"x-hasura-session-var1" : "..."
|
|
}
|
|
}
|
|
|
|
Sample request
|
|
**************
|
|
|
|
.. code-block:: http
|
|
|
|
POST /v1/graphql/explain HTTP/1.1
|
|
Content-Type: application/json
|
|
|
|
{
|
|
"query": {
|
|
"query": "query getAuthors { authors { name }}",
|
|
"operationName": "getAuthors"
|
|
}
|
|
}
|
|
|
|
|
|
Response
|
|
^^^^^^^^
|
|
|
|
The response for a query is a list of plans:
|
|
|
|
.. code-block:: none
|
|
|
|
[
|
|
{
|
|
"field": String -- "name of the field",
|
|
"sql": String -- "the generated SQL for the operation",
|
|
"plan": [String] -- "Postgres's plan for the generated SQL"
|
|
}
|
|
]
|
|
|
|
The response for a subscription is a single plan:
|
|
|
|
.. code-block:: none
|
|
|
|
{
|
|
"sql": String -- "the generated SQL for the operation",
|
|
"plan": [String] -- "Postgres's plan for the generated SQL"
|
|
}
|
|
|
|
Sample response for a query
|
|
***************************
|
|
|
|
.. code-block:: json
|
|
|
|
[
|
|
{
|
|
"field": "authors",
|
|
"sql": "SELECT coalesce(json_agg(\"root\" ), '[]' ) AS \"root\" FROM (SELECT row_to_json((SELECT \"_1_e\" FROM (SELECT \"_0_root.base\".\"name\" AS \"name\" ) AS \"_1_e\" ) ) AS \"root\" FROM (SELECT * FROM \"public\".\"authors\" WHERE ('true') ) AS \"_0_root.base\" ) AS \"_2_root\" ",
|
|
"plan": [
|
|
"Aggregate (cost=14.27..14.27 rows=1 width=32)",
|
|
" -> Seq Scan on authors (cost=0.00..11.83 rows=610 width=32)",
|
|
" SubPlan 1",
|
|
" -> Result (cost=0.00..0.00 rows=1 width=32)"
|
|
]
|
|
}
|
|
]
|
|
|
|
Sample response for a subscription
|
|
**********************************
|
|
|
|
.. code-block:: json
|
|
|
|
{
|
|
"sql": "\n select\n _subs.result_id, _fld_resp.root as result\n from\n unnest(\n $1::uuid[], $2::json[]\n ) _subs (result_id, result_vars)\n left outer join lateral\n (\n SELECT coalesce(json_agg(\"root\" ), '[]' ) AS \"root\" FROM (SELECT row_to_json((SELECT \"_1_e\" FROM (SELECT \"_0_root.base\".\"name\" AS \"name\" ) AS \"_1_e\" ) ) AS \"root\" FROM (SELECT * FROM \"public\".\"authors\" WHERE ('true') ) AS \"_0_root.base\" ) AS \"_2_root\" \n ) _fld_resp ON ('true')\n ",
|
|
"plan": [
|
|
"Nested Loop Left Join (cost=14.27..14.93 rows=100 width=48)",
|
|
" -> Function Scan on _subs (cost=0.00..0.30 rows=100 width=16)",
|
|
" -> Materialize (cost=14.27..14.28 rows=1 width=32)",
|
|
" -> Aggregate (cost=14.27..14.27 rows=1 width=32)",
|
|
" -> Seq Scan on authors (cost=0.00..11.83 rows=610 width=32)",
|
|
" SubPlan 1",
|
|
" -> Result (cost=0.00..0.00 rows=1 width=32)"
|
|
]
|
|
}
|
|
|
|
Disabling Explain API
|
|
---------------------
|
|
|
|
The Explain API is part of the :ref:`Metadata API <metadata_apis>` and can only be disabled by disabling the same.
|