TableSink in TableEnvironment as well as in ConnectTableDescriptor. The affected
TableEnvironment::registerTableSink
ConnectTableDescriptor::registerTableSource
ConnectTableDescriptor::registerTableSink
ConnectTableDescriptor::registerTableSourceAndSink
(Most of them are already deprecated, except for TableEnvironment::fromTableSource,
which was intended to deprecate but missed by accident).
FLIP-64 [1] already explained why we want to deprecate TableSource & TableSink from
user's interface. In a short word, these interfaces should only read & write the physical
representation of the table, and they are not fitting well after we already introduced some
logical table fields such as computed column, watermarks.
Another reason is the exposure of registerTableSource in Table Env just make the whole
SQL protocol opposite. TableSource should be used as a reader of table, it should rely on
other metadata information held by framework, which eventually comes from DDL or
ConnectDescriptor. But if we register a TableSource to Table Env, we have no choice but
have to rely on TableSource::getTableSchema. It will make the design obscure, sometimes
TableSource should trust the information comes from framework, but sometimes it should
also generate its own schema information.
Furthermore, if the authority about schema information is not clear, it will make things much
more complicated if we want to improve the table api usability such as introducing automatic
schema inference in the near future.
Since this is an API break change, I've also included user mailing list to gather more feedbacks.
Locked
