To view your schema, look for the schema browser button in the navigation bar on the left edge of the app:

Use the connection and database chooser dropdown buttons at the top of the panel to select a server to browse:

To refresh your schema, click the refresh icon:

If you have multiple schemas (eg PostgreSQL) or datasets (eg BigQuery), you can use the schema filter to select which to display:

Type a search term to filter your schema data and quickly find what you are looking for: