[discuss] Transaction API's autocommit

[kevinjqliu]

Porting over from #1246

Can be a potential footgun (#1246 (comment))
Autocommit usage (#1246 (comment))

However, there may still be some concerns around this since Transaction is a public class. If this is the case, I think we can start from making the parameter "private" (autocommit -> _autocommit) and/or adding some doc to explain the usage.

[kevinjqliu]

The idea is to make the code simpler if we only want to evolve schema/spec/...
i.e.

with table.update_schema() as update:
    update.add_column("some_field", IntegerType(), "doc")

instead of another with..transaction wrapper

with table.transaction() as transaction:
    with transaction.update_schema() as update_schema:
        update.add_column("some_other_field", IntegerType(), "doc")

....

What about moving the autocommit logic out of Transaction and into the class that uses it instead?

For example, UpdateSchema can implement __enter__ and __exit__ to commit the transaction automatically?

Currently, these classes use autocommit=True:

• ManageSnapshots
• UpdateSchema
• UpdateSpec