Mailing-List: contact derby-user-help@db.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Derby Discussion" <derby-user@db.apache.org>
Received-SPF: pass (hermes.apache.org: local policy)
Message-ID: <429F4B82.8080805@mgrinformatica.com.br>
Date: Thu, 02 Jun 2005 15:10:10 -0300
From: Edson Carlos Ericksson Richter <edson.richter@mgrinformatica.com.br>
User-Agent: Mozilla Thunderbird 1.0 (X11/20041206)
MIME-Version: 1.0
To: Derby Discussion <derby-user@db.apache.org>
Subject: Re: Server side cursor
References: <429B7338.5060704@mgrinformatica.com.br>
 <429CA561.2090800@Sourcery.Org> <429CB161.2080706@mgrinformatica.com.br>
 <429D8B46.6050708@Sourcery.Org> <429F4482.8030607@Sourcery.Org>
In-Reply-To: <429F4482.8030607@Sourcery.Org>
Content-Type: multipart/mixed;
 boundary="------------000003090108000906060908"

This is a multi-part message in MIME format.
--------------000003090108000906060908
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 8bit

Yes, that's what I have in mind.

See, if I issue a very large, expensive select * from huge_table, if I 
have server side cursors, response is immediate, because there is 
nothing to process. My cursor is just a pointer to real data in the table.

Even if I make a select * from huge_table order by some_column, if the 
column is indexed, the server-side cursor is just a pointer to index... 
And real action goes when I scroll records...

Thanks for clarification.

Richter


Satheesh Bandaram escreveu:

> Thinking about this some more, may be you mean SQL cursors by 
> "server-side cursors". These are definitely not supported by Derby. 
> Derby only has JDBC based cursors. SQL cursors didn't leap to my head, 
> since Derby doesn't have them.
>
> Satheesh
>
> Satheesh Bandaram wrote:
>
>>By "server-side cursors", do you mean the ability to process on the
>>server, using procedures/functions? Same cursor mechanism works on the
>>server too. See if 'Derby server-side programming' part in developer
>>guide provides more info:
>>
>>http://incubator.apache.org/derby/docs/devguide/cdevspecial.html
>>
>>Satheesh
>>
>>Edson Carlos Ericksson Richter wrote:
>>
>>  
>>
>>>Thanks.
>>>
>>>I made a fgrep -iR "server side" * in docs and found nothing about it.
>>>a fgrep -iR "cursor" * found several docs, but none specific about
>>>server side cursors.
>>>
>>>Even a fgrep -iR "cursor" | egrep -i "server" reveal no doc about
>>>server side cursor.
>>>
>>>May be the terminoly I'm looking for is wrong. Under what name server
>>>side cursor subject could be find?
>>>
>>>Thanks again,
>>>
>>>Edson Richter
>>>
>>>
>>>
>>>Satheesh Bandaram escreveu:
>>>
>>>    
>>>
>>>>Derby certainly can. Data for cursors in Derby is fetched on demand.
>>>>Check Derby documentation for more info.
>>>>
>>>>Satheesh
>>>>
>>>>Edson Carlos Ericksson Richter wrote:
>>>>
>>>> 
>>>>
>>>>      
>>>>
>>>>>Is derby able to delivery very large resultsets (really bigger than
>>>>>phisical memory of the db server) throught server side cursors?
>>>>>
>>>>>Thanks,
>>>>>
>>>>>  
>>>>>        
>>>>>
>>>>
>>>> 
>>>>
>>>>      
>>>>
>>>    
>>>
>>
>>  
>>


-- 
Edson Carlos Ericksson Richter
MGR Inform�tica Ltda.
Fones: 3347-0446 / 9259-2993


--------------000003090108000906060908
Content-Type: text/x-vcard; charset=utf-8;
 name="edson.richter.vcf"
Content-Transfer-Encoding: 7bit
Content-Disposition: attachment;
 filename="edson.richter.vcf"

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


--------------000003090108000906060908--