Fix N+1 queries for children list
We're having a few N+1 issues in our Hierarchy widget when loading children and additional data. This leads to us being above the error budget in Product Planning, since the `workItemTreeQuery` often takes >2 seconds to load.
In the issues you can find a few queries that are already identified to have N+1 issues, but there are more than that. If you find another N+1 problem, add it as an issue to this epic.
<details><summary>workItemTreeQuery</summary>
## Query to test
```graphql
query workItemTreeQuery($id: WorkItemID!, $pageSize: Int = 100, $endCursor: String) {
workItem(id: $id) {
namespace {
id
fullName
__typename
}
...WorkItemHierarchy
__typename
}
}
fragment WorkItemHierarchy on WorkItem {
id
workItemType {
id
name
iconName
__typename
}
title
confidential
userPermissions {
deleteWorkItem
updateWorkItem
adminParentLink
setWorkItemMetadata
createNote
adminWorkItemLink
__typename
}
widgets {
type
... on WorkItemWidgetHierarchy {
type
hasChildren
depthLimitReachedByType {
workItemType {
id
name
__typename
}
depthLimitReached
__typename
}
rolledUpCountsByType {
countsByState {
opened
all
closed
__typename
}
workItemType {
id
name
iconName
__typename
}
__typename
}
parent {
id
__typename
}
children(first: $pageSize, after: $endCursor) {
pageInfo {
...PageInfo
__typename
}
count
nodes {
id
iid
confidential
workItemType {
id
name
iconName
__typename
}
namespace {
id
fullPath
name
__typename
}
title
state
createdAt
closedAt
webUrl
reference(full: true)
widgets {
... on WorkItemWidgetHierarchy {
type
hasChildren
rolledUpCountsByType {
countsByState {
all
closed
__typename
}
workItemType {
id
name
iconName
__typename
}
__typename
}
__typename
}
...WorkItemMetadataWidgets
__typename
}
__typename
}
__typename
}
__typename
}
...WorkItemMetadataWidgets
__typename
}
__typename
}
fragment PageInfo on PageInfo {
hasNextPage
hasPreviousPage
startCursor
endCursor
__typename
}
fragment WorkItemMetadataWidgets on WorkItemWidget {
type
... on WorkItemWidgetStartAndDueDate {
dueDate
startDate
__typename
}
... on WorkItemWidgetWeight {
weight
rolledUpWeight
widgetDefinition {
editable
rollUp
__typename
}
__typename
}
... on WorkItemWidgetProgress {
progress
updatedAt
__typename
}
... on WorkItemWidgetHealthStatus {
healthStatus
rolledUpHealthStatus {
count
healthStatus
__typename
}
__typename
}
... on WorkItemWidgetMilestone {
milestone {
...MilestoneFragment
__typename
}
__typename
}
... on WorkItemWidgetAssignees {
allowsMultipleAssignees
canInviteMembers
assignees {
nodes {
...User
__typename
}
__typename
}
__typename
}
... on WorkItemWidgetLabels {
allowsScopedLabels
labels {
nodes {
...Label
__typename
}
__typename
}
__typename
}
... on WorkItemWidgetLinkedItems {
linkedItems {
nodes {
linkId
linkType
__typename
}
__typename
}
__typename
}
__typename
}
fragment Label on Label {
id
title
description
color
textColor
__typename
}
fragment User on User {
id
avatarUrl
name
username
webUrl
webPath
__typename
}
fragment MilestoneFragment on Milestone {
expired
id
title
state
startDate
dueDate
webPath
__typename
}
```
### Variables
```json
{
"pageSize": 50,
"id": "gid://gitlab/WorkItem/144139838",
"endCursor": ""
}
```
</details>
epic