# Synchronizing metadata connections and database structures

Available in...

* Big Data Platform
* Cloud API Services Platform
* Cloud Big Data Platform
* Cloud Data Fabric
* Cloud Data Management Platform
* Data Fabric
* Data Management Platform
* Data Services Platform
* MDM Platform
* Real-Time Big Data Platform

When the data in a source database is changed or updated, it is necessary that the relevant connection structure in Talend 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 incoherence. 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.

### In this section

* [Synchronizing and reloading catalog and schema lists](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2024-06/synchronizing-and-reloading-catalog-and-schema-lists)
* [Synchronizing and reloading table lists](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2024-06/synchronizing-and-reloading-table-lists)
* [Synchronizing and reloading column lists](https://help.qlik.com/talend/en-US/studio-user-guide/8.0-R2024-06/synchronizing-and-reloading-column-lists)