Re: String-with-number sort and insert order preservation

From: Marek Šab (msab..uk.cvut.cz)
Date: Wed Feb 03 2010 - 12:20:00 EST

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    Hi,

    again thanks for answers, I will do for now pretty much what Andrey
    suggested - do subsequent commits as this is "one-time" operation and
    when the network will grow I will again populute the range in db (no
    more than 10k hosts)

    @Ari - yeah I overlooked this when you said it first time, but as I've
    already said, this table is mere list/enumeration for now and needs to
    be populated once per db lifetime

    Cheers, 

    --
Marek Šabo

    On 02/03/2010 01:44 PM, Andrey Razumovsky wrote:
> Actually, no. If you need to index data by IP, you just add indexing by IP
> column. If you want to perform in future meaningful sort by meaningless IP,
> you will have to think about such cases as changes the IP column - then the
> order might break. Answering your question, if you really think you need
> control over PK values, you either use custom PKs (and generate them
> yourself), or, if the speed isn't priority, do many sequent commits instead
> of one (if the logic of your app allows you)
>
> 2010/2/3 Marek Šabo <msab..uk.cvut.cz>
>
>   
>> Thank you all for your ideas, my progress:
>>
>>
>>
>>  1) Is there any way to sort varchar fields which happen to numbers, more
>>     
>>> precisely ipv4s?
>>> query.addOrdering(Ip4Address.IP_ADDRESS_PROPERTY, SortOrder.ASCENDING);
>>> This of course sets the hundreds as first in line, any tips on some
>>> custom sorting?
>>>
>>>
>>>       
>> I just implemented custom comparator and added the result list from query
>> to treeset - anyway the IPs are unique.
>>
>>     
>>> 2) Is there any way how to override this mechanism in order to preserve
>>> order of inserted rows?
>>>
>>>
>>>
>>>       
>> This one I can't really cope with. Of course I could fill it in ten other
>> ways which will preserve the order of inserted rows, so really, haven't any
>> of you ever needed or wanted the data to be indexed by auto-generated pk in
>> order you add them to context while in persisting phase? Because that would
>> nicely solve issue #1 as well because the IPs would be sorted according to
>> pk. This is collateral functionality that's why it isn't designed as OOP
>> would preach.
>>
>> Regards,
>>
>> Marek
>>
>>     
>
>
>

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