If you use the Data Catalog feature for Tableau Server (with the data management add-on), we recommend upgrading to Tableau Server 2019.3.4 or later. These versions contain a fix for an issue that prevents lineage from populating, database permissions not taking effect, and vizzes loading slowly. For more information, please see this Knowledge Base article.
Changes were applied to improve security. See ADV-2019-027, ADV-2019-031, ADV-2019-033, ADV-2019-034, ADV-2019-036, ADV-2019-037, ADV-2019-038, ADV-2019-040, ADV-2019-041, ADV-2019-042, ADV-2019-043, ADV-2019-044, ADV-2019-045, and ADV-2019-046 in Security Bulletins for more details.