```
DROP TABLE IF EXISTS foo;

CREATE TABLE foo (timestamp DateTime, x UInt64)
ENGINE = MergeTree PARTITION BY toYYYYMMDD(timestamp)
ORDER BY (timestamp);

INSERT INTO foo (timestamp, x) SELECT toDateTime('2020-01-01 00:05:00'), number from system.numbers_mt LIMIT 100;

SELECT count() FROM system.mutations; -- ok

ALTER TABLE foo UPDATE x = 1 WHERE x = (SELECT x from foo WHERE x = 1);

SELECT count() FROM system.mutations; -- stuck

```
if (storage)
        {
            std::vector<String> hint_name{};
            for (const auto & name : columns_context.requiredColumns())
            {
                auto hints = storage->getHints(name);
                hint_name.insert(hint_name.end(), hints.begin(), hints.end());
            }
            if (!hint_name.empty())
            {
                ss << ", maybe you meant: ";
                ss << toString(hint_name);
            }
        }
        else
        {
            if (!source_column_names.empty())
                for (const auto & name : columns_context.requiredColumns())
                    ss << " '" << name << "'";
            else
                ss << ", no source columns";
        }
        if (columns_context.has_table_join)
        {
            ss << ", joined columns:";
            for (const auto & column : analyzed_join->columnsFromJoinedTable())
                ss << " '" << column.name << "'";
        }
        if (!array_join_sources.empty())
        {