Whether to compare characters case insensitively for enum columns. It only matters for ingestion client as it's the place to concert enum strings to enum values.

We store the default value as string here since it's from user input. Nil means the default value is NULL. Actual default value of column data type should be stored in memstore.

Deleted columns are kept as placeholders in Table.Columns.

Whether disable enum cases auto expansion.

Immutable, columns cannot be renamed.

Immutable, columns cannot have their types changed.