Statistics
https://play.clickhouse.com/play?user=play#c2VsZWN0IAp0b1N0YXJ0T2ZIb3VyKGNoZWNrX3N0YXJ0X3RpbWUpIGFzIGQsCmNvdW50KCksICBncm91cFVuaXFBcnJheShwdWxsX3JlcXVlc3RfbnVtYmVyKSwgIGFueShyZXBvcnRfdXJsKQpmcm9tIGNoZWNrcyB3aGVyZSAnMjAyMi0wNi0wMScgPD0gY2hlY2tfc3RhcnRfdGltZSBhbmQgdGVzdF9uYW1lIGxpa2UgJyUwMjQ5MV9wYXJ0X2xvZ19oYXNfdGFibGVfdXVpZCUnIGFuZCB0ZXN0X3N0YXR1cyBpbiAoJ0ZBSUwnLCAnRkxBS1knKSBncm91cCBieSBkIG9yZGVyIGJ5IGQgZGVzYw==

Some times there are not output from requests.
const StorageMetadataPtr & metadata_snapshot,
    const PartitionCommands & commands,
    ContextPtr query_context)
{
    PartitionCommandsResultInfo result;
    for (const PartitionCommand & command : commands)
    {
        PartitionCommandsResultInfo current_command_results;
        switch (command.type)
        {
            case PartitionCommand::DROP_PARTITION:
            {
                if (command.part)
                {
                    auto part_name = command.partition->as<ASTLiteral &>().value.safeGet<String>();
                    checkPartCanBeDropped(part_name);
                    dropPart(part_name, command.detach, query_context);
                }
                else
                {
                    checkPartitionCanBeDropped(command.partition, query_context);
                    dropPartition(command.partition, command.detach, query_context);
                }
            }
            break;
            case PartitionCommand::DROP_DETACHED_PARTITION:
                dropDetached(command.partition, command.part, query_context);
                break;