Cloned Tables: Default Value for Columns Not Allowed¶

The default value for a column cannot be dropped if the column was added to a table using the ALTER TABLE command. This restriction prevents inconsistency between values in rows inserted before the column was added and rows inserted after the column was added.

If you create a clone of that table, the column with the DEFAULT value does not inherit the restriction in some cases.

Columns in cloned tables behave as follows:

Previously:

If a source table has a column with a default value that was added after table creation time (that is, using the ALTER TABLE command), dropping the default value for that column is blocked.

If a table is cloned from that source table, it might not inherit the restriction on dropping the DEFAULT value in some cases.

Currently:

The columns in the cloned table will inherit the intended behavior from its source table.

Ref: 948