Feature: Add more data type support for key

[jaredzhou]

Feature description

this pg connector only support int type key for table for now , i don't see the reason, i think other type like varchar is possible, and it's common to use uuid or varchar as primary key

[lovromazgon]

We currently don't support them because we were focusing on making it possible to do an incremental snapshot (i.e. if the snapshot is interrupted we don't have to start the snapshot again from scratch). This is specifically important for huge tables where the snapshot can take hours or even days. That's why we currently have the restriction for keys to be an ordinal type that's auto-incremented. However, we do plan to add support for other types, with the caveat of not being able to do an incremental snapshot.

[jaredzhou]

that make sense, glad to see the support for varchar.

[lovromazgon]

I realized that you can still use the connector to move data continuously using logical replication (CDC), the restriction on the primary key type only applies to snapshots.