[SQL] Client and server cursors // deferred ClientSide

[Ruslan Zasukhin]

on 3/5/03 6:13 PM, 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.

Correct. 

IF you know that your query can get so many records you need use Serverside
cursor, or LIMIT 

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

Of course!

-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
-------------------------------------------------------------
e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

To subscribe to the Valentina mail list go to:
http://listserv.macserve.net/mailman/listinfo/valentina
-------------------------------------------------------------