By catch on
Change record status: 
Published (View all published change records)
Project: 
Drupal core
Introduced in branch: 
11.2.x
Introduced in version: 
11.2.0
Issue links: 
https://www.drupal.org/node/2930736
Description: 

Drupal\views\EntityViewsData::$fieldStorageDefinitions and Drupal\views\EntityViewsData::getFieldStorageDefinitions() have both been deprecated. These were protected properties/methods and no replacement is provided. The field schema should be obtained directly from the field definition now.

Before:
$field_schema = $this->getFieldStorageDefinitions()[$field_name]->getSchema();

After
$field_schema = $field_definition->getFieldStorageDefinition()->getSchema();

Impacts: 
Module developers