[SQL] Client and server cursors

[Ruslan Zasukhin]

on 3/5/03 12:20 AM, Gunnar Swan at GunnarSwan at practicetopass.com wrote:

>> IF you want change or add or delete some record of this cursor, you need
>> send to server OTHER SQL command as
>>        "INSERT ... " or
>>        "UPDATE .. WHERE ID = N"
>>        "DELETE .. WHERE ID = N"
>>        
> 
> And create a new cursor to modify a record or add new record.
> This is ok. I do this today.
> Many times I use joins to fetch recordset (cursor). I rarely
> write records to a joined recordset. I almost always open
> new cursor and insert to the table, then refresh.
> 
> 
>> -----
>> What we try now implement for Valentina is ability to use the SAME cursor
>> API, that we use for local dbs.
>> 
>> So this looks as
>> 
>>    curs = db.SqlSelect( "SELECT ...", ReadWrite, kClient )
>> 
>> Now if you want do modifications of records you can do simply:
>> 
>>    curs.Stringfield( "name" ) = 'something new'
>>    curs.Update();  <<<<<<<< this send command to server.
>>    
>> €€>> What you think about this approach ?
> 
> Does this not imply many open, scrolling cursors on server ?
> And lots of RAM for cursors ?

Yes!  But since you can decide what you want you must be able tune it.
For busy servers of course better avoid many cursors on server side.
For intranet servers that have e.g. 20-5 users this is not big problem, can
be be more effective.

> Over TCP/IP ?

So what?  Look on your own description of YOUR current steps.
You ALSO right now send SQL command, so there is no additional overhead on
network. In fact it can be even less because data are sent in binary format.

> If on internet, is data encrypted or the transmission ?

The same is for way of SQL command.

Encrypt or not encrypt data on net, this is other question.

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

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