**Use case**
mysql repl to clickhouse

**Describe the solution you'd like**
Hope MaterializeMySQL engine can support MySQL prefix index



return makeASTFunction("toYYYYMM", std::make_shared<ASTIdentifier>(primary_key.name));
        }
        if (type->haveMaximumSizeOfValue() && (!best_size || type->getSizeOfValueInMemory() < best_size))
        {
            if (which.isInt8() || which.isUInt8())
            {
                best_size = type->getSizeOfValueInMemory();
                best_partition = numbers_partition(primary_key.name, std::numeric_limits<UInt8>::max());
            }
            else if (which.isInt16() || which.isUInt16())
            {
                best_size = type->getSizeOfValueInMemory();
                best_partition = numbers_partition(primary_key.name, std::numeric_limits<UInt16>::max());
            }
            else if (which.isInt32() || which.isUInt32())
            {
                best_size = type->getSizeOfValueInMemory();
                best_partition = numbers_partition(primary_key.name, std::numeric_limits<UInt32>::max());
            }
            else if (which.isInt64() || which.isUInt64())
            {
                best_size = type->getSizeOfValueInMemory();
                best_partition = numbers_partition(primary_key.name, std::numeric_limits<UInt64>::max());
            }
        }
    }
    return best_partition;
}
static ASTPtr getOrderByPolicy(