Fatal error: Allowed memory size exhausted

Problem/Motivation

If there are a lot of records to reference to, a fatal error occurs: Allowed memory size exhausted in web/core/lib/Drupal/Core/Entity/Sql/SqlContentEntityStorage.php on line 484.

Steps to reproduce

• Create around 100'000 records of a content type to reference
• Create a content type with an entity reference field to the before mentioned content type
• Install verf module
• Create a view of the second content type
• In the Filter criteria section click on "Add"
• In "Add filter criteria" modal dialog select the entity reference field verf filter
• Click on "Apply" in the modal dialog
• The dialog remains open, close it by clicking on top right x
• Reload the views page

Proposed resolution

The error is caused by too many referenceable entities. Therefore, add some sort of limit in Drupal\verf\Plugin\views\filter\EntityReference::getReferenceableEntities(), both if no target bundles are selected and if target bundles are selected on the filter configuration form.