ref #9436
Currently EPHEMERAL column requires an explicit default value provided on CREATE TABLE - we can allow implicit default there

TableProperties properties = getTablePropertiesAndNormalizeCreateQuery(create);
    DatabasePtr database;
    bool need_add_to_database = !create.temporary;
    if (need_add_to_database)
        database = DatabaseCatalog::instance().getDatabase(database_name);
    if (need_add_to_database && database->getEngineName() == "Replicated")
    {
        auto guard = DatabaseCatalog::instance().getDDLGuard(create.getDatabase(), create.getTable());
        if (auto * ptr = typeid_cast<DatabaseReplicated *>(database.get());
            ptr && !getContext()->getClientInfo().is_replicated_database_internal)
        {
            assertOrSetUUID(create, database);
            guard->releaseTableLock();
            return ptr->tryEnqueueReplicatedDDL(query_ptr, getContext());
        }
    }
    if (create.replace_table)
        return doCreateOrReplaceTable(create, properties);
    
    bool created = doCreateTable(create, properties);
    if (!created)   
        return {};
    
    QualifiedTableName qualified_name{database_name, create.getTable()};
    TableNamesSet loading_dependencies = getDependenciesSetFromCreateQuery(getContext()->getGlobalContext(), qualified_name, query_ptr);
    if (!loading_dependencies.empty())
        DatabaseCatalog::instance().addLoadingDependencies(qualified_name, std::move(loading_dependencies));
    return fillTableIfNeeded(create);
}
bool InterpreterCreateQuery::doCreateTable(ASTCreateQuery & create,