WebClasses and Performance

[David]

I'm pretty new to WebClasses. I'm writing a VB WebClass app that takes data
from an Access97
database and presents it in table format. Pretty simple stuff.

However, sometimes I'm building a table of 200-300 rows. My WebClass code
simply takes the data on
each row of the table, slaps a <TD> before it and a </TD> behind it, and
concatenates the whole
table together in a string variable.

At the end of the routine, I set my TagContents to equal the string variable
holding the table.

When my recordset is small, the WebClass runs fine. However, when the recordset
is large (200-300
records), it takes forever to build the table string. I've done some quick
timings and, due to the
number of fields in my table, I'm only able to build 6-10 table rows a second.
For a 300 row table,
that's quite a wait!

Any suggestions on how to speed things up? I'm using constants wherever
I can. Also, when I test
the code (not in a WebClass) to output to a file or the intermediate window,
it runs much more quickly.

Has anyone else run into WebClass performance issues? How did you get around
them?

Thanks!
David.

[Lior Amar]

I don't have a solution for you using webclasses, I just thought I would my
2 cents on WebClasses....WebClasses are EVIL. They're an incredible
technology that simply doesn't work well yet. For your speed problem, have
you thought about using ASP and COM. Have a COM object create the string
for you in a nice tight loop and then simply instanciate that object from
ASP and do a Response.write objCom.CreatedString .

Remember WebClasses are EVIL....and it's too bad cause it sure is a kick ***
technology...Maybe they'll fix there bugs in VB7. They tend to also skip
tags when you have a lot of concurrent users.

"David" <hoerster@netscape.net> wrote in message
news:3950b640$1@news.devx.com...
>
> I'm pretty new to WebClasses. I'm writing a VB WebClass app that takes
data
> from an Access97
> database and presents it in table format. Pretty simple stuff.
>
> However, sometimes I'm building a table of 200-300 rows. My WebClass code
> simply takes the data on
> each row of the table, slaps a <TD> before it and a </TD> behind it, and
> concatenates the whole
> table together in a string variable.
>
> At the end of the routine, I set my TagContents to equal the string
variable
> holding the table.
>
> When my recordset is small, the WebClass runs fine. However, when the
recordset
> is large (200-300
> records), it takes forever to build the table string. I've done some
quick
> timings and, due to the
> number of fields in my table, I'm only able to build 6-10 table rows a
second.
> For a 300 row table,
> that's quite a wait!
>
> Any suggestions on how to speed things up? I'm using constants wherever
> I can. Also, when I test
> the code (not in a WebClass) to output to a file or the intermediate
window,
> it runs much more quickly.
>
> Has anyone else run into WebClass performance issues? How did you get
around
> them?
>
> Thanks!
> David.

[Jim Pragit]

"Lior Amar" <lior_amar@hotmail.com> wrote:
>Remember WebClasses are EVIL....and it's too bad cause it sure is a kick
***
>technology...Maybe they'll fix there bugs in VB7.

Based on what Microsoft's said so far about VB7, WebClasses appear to be
a 'dead' technology. WebClasses will probably be retained for backwards
compatibility but not much else.

- Jim

[Gary Nelson]

David,
Concatenating a lot of strings in VB is a ver slow process (WebClass or
not).

I use two methods to speed them up.

1) create a large string and place the variables where they belong using
MID$

2) open a file for output, print the variables to the file, close the file,
reopen it as binary, define a string as the same length as the file and get
the variable from the file.

Using MID$ is about 1000 times faster than concatenating, and I use it when
I really need the speed.

Using a file is about 100 times faster than concatenating in memory. Since
it´s easier to do than MID$ I use it when speed is not as important.

(By the way I haven't done actual timing on this since I first ran across
the problem when VB4 came out)

Gary

[Gary Nelson]

David,

Just out of curiosity I tested the speed for each method. It took 300 times
as long to concatenate in memory as it did to write to a file on the hard
drive, and mid$ was so fast I cound´t even get a reading on it without
increasing the iterations.

Gary

Dim x As Integer
a$ = String$(100, 65)

' test 1 concatenate in memory

tt! = Timer
For x% = 1 To 1000
b$ = b$ & a$
Next
Debug.Print Format$(Timer - tt!, "0.00000")

' test 2 concatenate using mid$

tt! = Timer
b$ = Space$(1000 * Len(a$))
For x = 1 To 1000
Mid$(b$, ((x - 1) * Len(a$)) + 1, Len(a$)) = a$
Next
Debug.Print Format$(Timer - tt!, "0.00000")

' test 3 concatenate using hard drive

tt! = Timer
fff = FreeFile
Open "temp" For Binary As fff
For x = 1 To 1000
Put fff, , a$
Next
b$ = Space$(LOF(fff))
Get fff, 1, b$
Close fff
Kill "temp"
Debug.Print Format$(Timer - tt!, "0.00000")

'results:
3.19141
0,00000
0,10938