Hello!

I think you can have two long fields (hi, lo) and have index on (hi asc, lo
asc). Such index will be around 20 bytes/rec.

Actually this will only give you 127 bit fields if I'm not mistaken, since
perhaps you don't want to use negative lo values.

Regards,
-- 
Ilya Kasnacheev


пт, 28 июн. 2019 г. в 20:38, Prasad Bhalerao <[email protected]>:

> The problem with BigInteger is it takes around 80 bytes. I will be having
> 2 BigInteger fields in my class which will take around 176 bytes per
> record. I will be having around 40 to 60 million such entries in my cache.
>
> So I am thinking to squeeze some bytes using two long numbers or using two
> byte arrays.
>
> How can I create index on byte array field and create index on it and use
> it in where clause. Can you give simple example?
>
> Also if I use Int128 data type, how can I create index on it and use it in
> where clause?
> Simple example would be helpful.
>
> Thanks,
> Prasad
>
> On Fri 28 Jun, 2019, 10:24 PM Ilya Lantukh <[email protected] wrote:
>
>> Hi,
>>
>> Theoretically, you can create an index and use >= and <= comparisons for
>> any data type. In your particular case, I think, using BigInteger is the
>> most straightforward approach.
>>
>> Hope this helps.
>>
>> On Fri, Jun 28, 2019 at 9:39 AM Prasad Bhalerao <
>> [email protected]> wrote:
>>
>>> Hi,
>>>
>>> I want to store 128 bit number as a one the field in value object in my
>>> cache.
>>>
>>> I can do that using multiple ways.
>>> e.g.
>>> 1) I can store 128 bit number using java.math.BigInteger.
>>>       a) But If store it using BigInteger, can I create index on this
>>> field?
>>>       b) How can I use this field in where clause to filter the data?
>>>
>>> 2) I can store 128 bit number using byte array (byte[]).
>>>     a) Can I create an index on byte array?
>>>     b) Can I use this byte array field in where clause to filter the
>>> data.
>>>         e.g.  mostly the where clause would be bytearr >=? and   bytearr
>>> <=
>>>
>>> 3) I can implement my own Number datatype e.g. Int128 using two long
>>> numbers and and I implement compareTo method which is a bit tricky.
>>>    a) I can create index on nested objects but how I can use this Int128
>>> data type field in where clause and make use of overridden compareTo method
>>> to filter the data?
>>>
>>> Can someone please advise?
>>>
>>>
>>>
>>> Thanks,
>>> Prasad
>>>
>>>
>>>

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