Major Description
We will store table schema in table properties for the read-side to restore. In Spark 3.1, we add char/varchar support natively. In some commands like `create table`, `alter table` with these types, the char
or varchar will be stored directly to those properties. If a user uses Spark 2 to read such a table it will fail to parse the schema.
A table can be a newly created one by Spark 3.1 and later or an existing one modified by Spark 3.1 and on.
