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
command.if_not_exists = command_ast->if_not_exists;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::ADD_PROJECTION)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.projection_decl = command_ast->projection_decl;
        command.type = AlterCommand::ADD_PROJECTION;
        const auto & ast_projection_decl = command_ast->projection_decl->as<ASTProjectionDeclaration &>();
        command.projection_name = ast_projection_decl.name;
        if (command_ast->projection)
            command.after_projection_name = command_ast->projection->as<ASTIdentifier &>().name();
        command.first = command_ast->first;
        command.if_not_exists = command_ast->if_not_exists;
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::DROP_CONSTRAINT)
    {
        AlterCommand command;
        command.ast = command_ast->clone();
        command.if_exists = command_ast->if_exists;
        command.type = AlterCommand::DROP_CONSTRAINT;
        command.constraint_name = command_ast->constraint->as<ASTIdentifier &>().name();
        return command;
    }
    else if (command_ast->type == ASTAlterCommand::DROP_INDEX)
    {
        AlterCommand command;
        command.ast = command_ast->clone();