| `Maximum field length` | See [the explanation in instance limits.](../administration/instance_limits.md#maximum-field-length). |
| `Maximum bulk request size (MiB)` | Repository indexing uses the Elasticsearch bulk request API. This setting determines the maximum size of an individual bulk request during these operations. |
| `Bulk request concurrency` | Each repository indexing operation may submit bulk requests in parallel. This increases indexing performance, but fills the Elasticsearch bulk requests queue faster. |
| `type` | string | yes | Type of panel to be rendered. For stacked column panel types, set to `stacked-column` |
| `query_range` | yes | yes | For stacked column panel types, you must use a [range query](https://prometheus.io/docs/prometheus/latest/querying/api/#range-queries) |
##### Single Stat
To add a single stat panel type to a dashboard, look at the following sample dashboard file:
> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/460) in [GitLab Premium](https://about.gitlab.com/pricing/) 12.8.
Approval rules are often only relevant to specific branches, like `master`.
When configuring [**Default Approval Rules**](#adding--editing-a-default-approval-rule)
these can be scoped to all the protected branches at once by navigating to your project's
**Settings**, expanding **Merge request approvals**, and selecting **Any branch** from
the **Target branch** dropdown.
Alternatively, you can select a very specific protected branch from the **Target branch** dropdown:
![Scoped to Protected Branch](img/scoped_to_protected_branch_v12_8.png)
To enable this configuration, see [Code Owner’s approvals for protected branches](../protected_branches.md#protected-branches-approval-by-code-owners-premium).
## Adding or removing an approval
When an [eligible approver](#eligible-approvers) visits an open merge request,