Connect a data source
Add the source
Open Data, choose Add source, and pick the system you want to read. You are asked to authorise the connection with that system, which is what grants us read access.
Choose the scope
Bring across only what you need. A narrow first sync finishes quickly and makes problems obvious; you can widen it afterwards without starting again.
The first sync
The first sync reads everything in scope and is the slowest one. Later syncs read only what changed.
You can keep working while it runs. Anything already synced is available immediately.
Permissions
A connection can only read what the account that authorised it can read. If records are missing, check that account's permissions in the source system before looking anywhere else.