**Describe the bug**

Since we upgraded to 20.10.3.30, one of our clickhouse cluster takes much more time to start. (Up to 50 minutes, and before it took ~3 minutes)
The log file is filled with
>  <Debug> DiskLocal: Reserving 1.00 MiB on disk `default`, having unreserved 16.90 TiB

Additionally, the memory consumption increases, linearly, a lot (up to arround 230 G for us) and then drop back to normal values once clickhouse finished starting up. During that loading phase, a single CPU core is used at 100%.
If that memory is not available for the machine, clickhouse gets OOMed by the kernel.


**How to reproduce**
* Issue appeared after we upgraded to ClickHouse server version 20.10.3.30

* How could I find wich of our tables may be responsible for that ?


**Expected behavior**
A fast startup :)

{
        return part->info;
    }
    static DataPartStateAndInfo dataPartPtrToStateAndInfo(const DataPartPtr & part)
    {
        return {part->getState(), part->info};
    }
    using DataPartsIndexes = boost::multi_index_container<DataPartPtr,
        boost::multi_index::indexed_by<
            
            boost::multi_index::ordered_unique<
                boost::multi_index::tag<TagByInfo>,
                boost::multi_index::global_fun<const DataPartPtr &, const MergeTreePartInfo &, dataPartPtrToInfo>
            >,
            
            boost::multi_index::ordered_unique<
                boost::multi_index::tag<TagByStateAndInfo>,
                boost::multi_index::global_fun<const DataPartPtr &, DataPartStateAndInfo, dataPartPtrToStateAndInfo>,
                LessStateDataPart
            >
        >
    >;
    
    mutable std::mutex data_parts_mutex;
    DataPartsIndexes data_parts_indexes;
    DataPartsIndexes::index<TagByInfo>::type & data_parts_by_info;
    DataPartsIndexes::index<TagByStateAndInfo>::type & data_parts_by_state_and_info;