https://clickhouse-test-reports.s3.yandex.net/18817/9049599e367bcccd809f45af138452f965b3303a/stress_test_(thread)/test_run.txt.out.log


if (command->type == ASTAlterCommand::DELETE)
    {
        MutationCommand res;
        res.ast = command->ptr();
        res.type = DELETE;
        res.predicate = command->predicate;
        res.partition = command->partition;
        return res;
    }
    else if (command->type == ASTAlterCommand::UPDATE)
    {
        MutationCommand res;
        res.ast = command->ptr();
        res.type = UPDATE;
        res.predicate = command->predicate;
        res.partition = command->partition;
        for (const ASTPtr & assignment_ast : command->update_assignments->children)
        {
            const auto & assignment = assignment_ast->as<ASTAssignment &>();
            auto insertion = res.column_to_update_expression.emplace(assignment.column_name, assignment.expression());
            if (!insertion.second)
                throw Exception("Multiple assignments in the single statement to column " + backQuote(assignment.column_name),
                    ErrorCodes::MULTIPLE_ASSIGNMENTS_TO_COLUMN);
        }
        return res;
    }
    else if (command->type == ASTAlterCommand::MATERIALIZE_INDEX)
    {
        MutationCommand res;
        res.ast = command->ptr();