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From Vic Cekvenich ...@basebeans.com>
Subject Re: RowSetDynaClass
Date Tue, 18 Feb 2003 13:32:36 GMT

Ans 1: In # 5 bellow I give you a Sun site where all the drivers are 
listed that do RowSet. I use this: 
http://jxdbcon.sourceforge.net/nightly , it's open source!

Ans 2: RowSet is THE most efficient and most scalable way, it is in fact 
JDBC. So you can't do better!
For large # of rows returned (which first you try to work arround) I use 
offset, as explained bellow in #4.

.V

Jack Zakarian wrote:
> Hi Vic,
> 
> Item 6 talks about CachedRowSets. I read the article and visited Sun's
> website. Its states that you can not use the binary's in commercial
> products.
> It also says that the data set is sent to the client. 
> 
> I have two questions
> 1. Is there an alternative to the CachedRowSet that can be used in
> commercial products? If not what do you use?
> 
> 2. Does using CachedRowSets cause a lot of network traffic if the size
> of the set is big?
> 
> Thanks,
> 
> Jack
> 
> -----Original Message-----
> From: Vic Cekvenich [mailto:vc@basebeans.com] 
> Sent: Tuesday, February 18, 2003 6:25 AM
> To: struts-user@jakarta.apache.org
> Subject: Re: RowSetDynaClass
> 
> (my post got lost) bellow:
> 
> Luiz-Otavio Zorzella wrote:
> 
>>Craig R. McClanahan wrote:
>>
>>>Sundar Narasimhan wrote:
>>>
>>>
>>>>I agree that this approach works well for "small" result
>>>>sets. However, if there are say 10k rows.. it would be nice to have
>>>>such a class work together with a Pager tag set.. any thoughts re.
> 
> that?
> 
>>>
>>>Sounds like a good problem that needs to be solved in a general way.
>>>Best way to get it addressed might be to put in an enhancement
> 
> request
> 
>>>against BeanUtils to add row index limits on the rows that are 
>>>returned by
>>>the list.
>>>
>>>  http://nagoya.apache.org/bugzilla/
>>
>>
>>I have another idea for dealing with paging, in the lines of 
>>ResultSetDynaClass... From an earlier email:
>>
>>********************
>>
>>I want, like in the a ResultSetDynaClass, a structure that does not
> 
> copy 
> 
>>the elements, from which I can get an Iterator. Now, once I
> 
> "getNext()" 
> 
>>from the Iterator, I want to get a copy of the object, so that I can 
>>later use it, even after exhauting the ResultSet. This is a "kind of"
> 
> a 
> 
>>lazy loading. BTW, the "advance ()" method is what I would use if I
> 
> want 
> 
>>to advance, but not have the copy generated...
>>
>>Maybe I could create a constructor for 
>>ResultSetDynaClass/ResultSetIterator that receives a boolean that 
>>specifies if I want copies of elements rather than references...
>>
>>*********************
>>
>>Zorzella
> 
> 
> 
> 1. Closing the RowSet is the traditioanl aproach, even in ODBC, 
> Client-Server or even in C API Client Side DB, very few drivers support 
> streaming rows.
> 
> 2. Most apps have hundreds of users, not many need thousands of 
> concurent users per CPU; but with above aproach several thosuand per CPU
> 
> on app. server works fine with sub second response time at least for my 
> clients.
> 
> 3. If you do go down the road (and best to pick up this thread in 
> Commons as mentioned) than 
> http://gee.cs.oswego.edu/dl/classes/collections/ are nice threaded 
> collections (part of JDK1.5 now). But be very carefull when creating own
> 
> threads on the app. server.
> 
> 4. 
> http://www.postgresql.org/docs/view.php?version=7.3&idoc=0&file=sql-sele
> ct.html
> one way is to pass the offset above to the RowSet via getParameter. This
> 
> works with large resultsets.
> 
> 5. Consider using RowSetDynaClass instead of ResultSetDynaClass...... 
> acctualy I allways use RowSet* never ResulstSet*. Copying is optional 
> with RowSet.
> Here are drivers that do RowSet (click rowset)
> http://industry.java.sun.com/products/jdbc/drivers
> 
> 
> 6. This sounds more of something Hibreanate should do and not Struts.
> And everyone knows my fave aproach is:
> http://developer.java.sun.com/developer/technicalArticles/javaserverpage
> s/cachedrowset 
> 
> Simple and fast (combined with offset on Select)
> 
> hth
> 
> .V
> 
> 
> 
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