[SQL] Client and server cursors // deferred ClientSide

[Andreas Grosam]

On Mittwoch, 5. März 2003, Ruslan Zasukhin <sunshine at public.kherson.ua> wrote:
>on 3/5/03 3:49 AM, Andreas Grosam at agrosam at computerworks.ch
>wrote:
>
>>>    curs = db.SqlSelect( "SELECT ...", ReadWrite, kClient )
>> 
>> Regarding Client versus Serve Side Cursor:
>
>> Defaults to a third version, which first manages the resources on the server
>> side - once fetched, they become onwed by the client and the server
>> immediately releases the fetched rows.
>
>Similar to mySQL's FETCH by one record, yes?
>
>> This may be called "defered" ClientSide Cursor. Combines several advantages at
>> low cost. 
>
>I have also another idea.
>
>Client Cursor load all data, Server kill main resources of server TMP
>cursor, but to be able now UPDATE that client cursor is created proxy -
>object of VDK_Cursor which do not keep recourse, but just talk to client
>cursor and update records.
>

Please consider the case where a cursor has millions of records. In this case transfering all the records to the client in order to get the cursor may  become impractical.

Certainly, there are allays pros and cons. A DB App developer should be able to control that.

>In the same time, CLIENT object on Server, still keep records locked.
>Well, yes, locks and time of unlock are defined by Isolation
>level.
>
>
>-- 
>Best regards,
>Ruslan Zasukhin      [ I feel the need...the need for speed ]
>-------------------------------------------------------------
>e-mail: ruslan at paradigmasoft.com
>web: http://www.paradigmasoft.com
>
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