When the data in a source database is changed or updated, it is necessary that the relevant connection structure in the studio follows that change or update as well. Otherwise, errors may occur when trying to analyze a column that has been modified/deleted in a database.
You can synchronize the connection structure displayed in the DQ Repository tree view with the database structures to eliminate any incoherences. You can perform synchronization at the following three different levels:
DB connection: to refresh the catalog and schema lists,
Tables: to refresh the list of tables,
Column: to refresh the list of columns.