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

Some times there are not output from requests.
};
namespace fs = std::filesystem;
namespace ProfileEvents
{
    extern const Event RejectedInserts;
    extern const Event DelayedInserts;
    extern const Event DelayedInsertsMilliseconds;
    extern const Event InsertedWideParts;
    extern const Event InsertedCompactParts;
    extern const Event InsertedInMemoryParts;
    extern const Event MergedIntoWideParts;
    extern const Event MergedIntoCompactParts;
    extern const Event MergedIntoInMemoryParts;
}
namespace CurrentMetrics
{
    extern const Metric DelayedInserts;
}
namespace
{
    constexpr UInt64 RESERVATION_MIN_ESTIMATION_SIZE = 1u * 1024u * 1024u; 
}
namespace DB
{
namespace ErrorCodes
{
    extern const int NO_SUCH_DATA_PART;
    extern const int NOT_IMPLEMENTED;
    extern const int DIRECTORY_ALREADY_EXISTS;
    extern const int TOO_MANY_UNEXPECTED_DATA_PARTS;