22.2.1.4422.

```
create table test_alias (K Int64, D Date, S String, B Int64 Alias length(S)) Engine=MergeTree order by K;
insert into test_alias select number, today(), 'sdfsdfsdfsdfsdfds' from numbers(10000000);

session1: 
clickhouse-benchmark -c 10 <<< "insert into test_alias select number, today(), 'sdfsdfsdfsdfsdfds' from numbers(10000)"

session2: 
alter table test_alias drop column B;
0 rows in set. Elapsed: 251.043 sec.
```

especially it can be a problem with S3 disks

Alias columns do not persist in parts even in columns.txt
else if (command_ast->type == ASTAlterCommand::REMOVE_TTL)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = AlterCommand::REMOVE_TTL;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::MODIFY_SETTING)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = AlterCommand::MODIFY_SETTING;
        command.settings_changes = command_ast->settings_changes->as<ASTSetQuery &>().changes;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::MODIFY_DATABASE_SETTING)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = AlterCommand::MODIFY_DATABASE_SETTING;
        command.settings_changes = command_ast->settings_changes->as<ASTSetQuery &>().changes;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::RESET_SETTING)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.type = AlterCommand::RESET_SETTING;
        for (const ASTPtr & identifier_ast : command_ast->settings_resets->children)
        {