To ensure that the AWS Glue Data Catalog is scalable and can handle an increasing volume of data sources and schemas, you should implement data partitioning and indexing strategies. This improves query performance and enables the catalog to efficiently manage large volumes of data. Periodically reviewing and optimizing the catalog structure can be helpful, but it may not be sustainable as the volume of data grows. Using AWS Glue crawlers can help with discovering and cataloging new data sources, but it does not directly address scalability. Leveraging AWS Lake Formation can provide additional governance and access control features, but it is not the primary solution for ensuring scalability.