[Qt-interest] C++ + QT vs C#

[Scott Aron Bloom]

Maybe you missed the point...

Both applications were written using the same algorithm,...
Reading in 1 line of the file at

-----Original Message-----
From: qt-interest-bounces at trolltech.com [mailto:qt-interest-bounces at trolltech.com] On Behalf Of Philippe Fremy
Sent: Thursday, March 19, 2009 11:05 AM
To: qt-interest at trolltech.com
Subject: Re: [Qt-interest] C++ + QT vs C#


Hi,

Given your description of how the previous programmer wrote his
application, all your number show is that this guy is a really really
bad programmer.

This does not really bring any good argument in the debate of C# vs C++
. A bad programmer can screw up any application, written in any
language, with any kind of library.

I maybe a bit harsh here, but before learning Qt, he should take some
computer classes.

cheers,

Philippe

Scott Aron Bloom wrote:
> Hope all you QT people like my numbers.. I’m pretty proud of them.
> 
>  
> 
> So I’ve been working on a project for a client, and the previous
> consultant (who had to leave the project but Im friends with) is a C#
> guy… Loves C# etc etc…  Claims the performance is great and that Im full
> of $%#@ when I say Ill stick with C++ when and I need performance…  And
> even if I don’t.. Ill still take C++ J
> 
>  
> 
> In taking over the project, essentially we had to be able to read in a
> tab separated file, with a random header, and insert it into a new
> table, using the first row as the field names of the database.
> 
>  
> 
> He wrote it in C# and had all but the insert into DB working.. Now.. I
> didn’t like his style (he read the whole file in at once and then used a
> string splitter to split the lines… 
> 
>  
> 
> Initially its app sat at 450MB to read in the 118k rows due to having
> the whole thing in memory + each line in memory…
> 
>  
> 
> Well we both wrote it to be read 1 line, process 1 line, maybe a bit
> slower… but not much..
> 
>  
> 
>  
> 
>                 C++(Console) C++(GUI)                C#
> 
> Memory before loading anything             6MB                      
> 9MB       22MB
> 
> Memory after reading each line
> 
> and inserting into DB                                     
> 6MB                       9MB       180MB (love heap managers…)
> 
> Memory after show db in GUI
> 
> In QT using QSqlQueryModel and
> QAbstractTableModel                                  
> NA                          12MB    450MB
> 
>  
> 
> Runtime to load                with NO DB connection
> 
> (release mode)                                
> 3s                            3s            9s
> 
> Runtime to load with DB inserts                               
> 210s                       210s       540s
> 
> Runtime to show in GUI                                               
> NA                          .5s          3.3s
> 
>  
> 
> Size of data…
> 
> ~118k rows of 105 columns of ~50 filled columns.
> 
>  
> 
> BTW.. I cant use BULK IMPORT commands because they are not SQL database
> agnostic.
> 
>  
> 
> Scott
> 
>  
> 
>  
> 
>  
> 
>  
> 
> 
> ------------------------------------------------------------------------
> 
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