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From Edson Carlos Ericksson Richter <edson.rich...@mgrinformatica.com.br>
Subject Re: Apache Derby (in the guise of Java DB) now shipping in Sun Java SE SDK
Date Fri, 16 Jun 2006 19:26:13 GMT
Sorry, but I can't agree...
1) So whenever I used the table, now I need to rewrite to use the view. 
Or should I start to use views everywhere?
2) What is impact of performance?
3) It can't be done if column is not null. Is not possible to change 
column to nullable (may be defining a default).

Any solution here is a wacky workaround for something near to simple... 
If Derby team really wan't to gain developers, need to think in them... 
not fight against.

Some hours ago, I've seen an announcement about JMX integration. It's 
beauty. But for a developer, it's mean near nothing, because management 
(as far as I could understand) is usefull if you have a database running...

Still too complicate. I really do prefer some "rename column 
TABLE.COLUMN to NEWCOLUMN" (like in SapDB/MaxDB) or some kind of ALTER 
TABLE ALTER COLUMN... like other databases do... and I (and others, be 
sure) will remain with other products until then...

tkx for the tips (besides I already knew them)...

Richter



Suavi Ali Demir escreveu:
> Add a new column to the table, copy the data into new column, change your view (drop-create)
to start using the new column and ignore the old column in the table.
>   Ali
>   
>
> Edson Carlos Ericksson Richter <edson.richter@mgrinformatica.com.br> wrote:
>   Just curious, how could a view change datatype of one column?
>
> AFAIK, I can create additional column into the table, then use an view 
> with alias to that column... But what happen if the column if part of 
> primary key? Or foreign key? A unique index? Then developer still need 
> to deal with migrating data, droping constraints, recreate, and so on.
>
> I do prefer think on views like "views" - not an workaround for missing 
> (and very important) database features.
>
>
> Richter
>
> Suavi Ali Demir escreveu:
>   
>> Updateable views would make it easy. Regards, Ali
>>
>>
>> Edson Carlos Ericksson Richter wrote:
>> Unfortunately, for developers, TBDITW don't allow change column names, 
>> datatypes, nullability, etc...
>> At least, no without large efforts (like creating a new table, migrating 
>> all data to new table, dropping constraints & table, creating a table 
>> with correct columns, copying data back, recreating constraints...)
>>
>> So is still necessary to develop in another database of preference (to 
>> get speed and productivity), then migrate to Derby... and cross fingers 
>> to not need change anything after app is in production, because changing 
>> a column on a table with million of records take hours... and need too 
>> much attention to not make mistakes, then I give it up. Forget. I can't 
>> deal with Derby in production, not now... I'll be very happy when this 
>> would be possible.
>>
>> Anyway, it's a great database... work like a charm in static database 
>> schemas...
>>
>>
>> Sorry by the rant,
>>
>> Richter
>>
>>
>> David Van Couvering escreveu:
>>
>>     
>>> As you may or may not have seen on the blogosphere, build 88 of 
>>> Mustang includes Java DB 10.2, Sun's supported distribution of Derby 
>>> 10.2.
>>>
>>> This is great news, both for our team and for developers. Developers 
>>> get the Best Database In the World (TM) out-of-the box, and Derby will 
>>> likely get a lot more users and attention!
>>>
>>> If you want to check it out, please go to
>>>
>>> http://download.java.net/jdk6/binaries/
>>>
>>> David
>>>
>>>
>>>
>>>
>>>       
>> begin:vcard
>> fn:Edson Carlos Ericksson Richter
>> n:Richter;Edson
>> org;quoted-printable:MGR Inform=C3=A1tica Ltda;Desenvolvimento
>> adr:Cristo Redentor;;Assis Brasil, 3257, Sala 409;Porto Alegre;RS;91010007;Brasil
>> email;internet:edson.richter@mgrinformatica.com.br
>> title:Diretor de Sistemas
>> tel;work:(51)3347-0446
>> tel;cell:(51)9259-2993
>> x-mozilla-html:FALSE
>> url:http://www.mgrinformatica.com.br
>> version:2.1
>> end:vcard
>>
>>
>>
>>
>>     
>
> begin:vcard
> fn:Edson Carlos Ericksson Richter
> n:Richter;Edson
> org;quoted-printable:MGR Inform=C3=A1tica Ltda;Desenvolvimento
> adr:Cristo Redentor;;Assis Brasil, 3257, Sala 409;Porto Alegre;RS;91010007;Brasil
> email;internet:edson.richter@mgrinformatica.com.br
> title:Diretor de Sistemas
> tel;work:(51)3347-0446
> tel;cell:(51)9259-2993
> x-mozilla-html:FALSE
> url:http://www.mgrinformatica.com.br
> version:2.1
> end:vcard
>
>
>
>   


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