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Hi,
Working on big data sets will probably end up being terribly slow. If you can stream the data, it might be orders of magnitude faster.
You haven't told anything useful so far, explain what kind of data it is, where it comes from, what you want to do with it, how long it is allowed to take, and exactly why you want to close the database.
Luc Pattyn
Have a look at my entry for the lean-and-mean competition; please provide comments, feedback, discussion, and don’t forget to vote for it! Thank you.
Local announcement (Antwerp region): Lange Wapper? Neen!
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My app saves data (string) in the database which is of .mdb format.
At the startup all the data from the database is loaded into the memory
because the app needs to iterate through the data many times.
I think it will be faster to iterate through the string array rather than
iterating through the database, thats why i load it in a string array. am I correct in thinking so?
I use ADODB to connect to the database.
Is there a way to have the strings in the memory, without eating up the RAM?
how do i convert the data into stream?
well what is stream anyway?
TheMrProgrammer
http://www.icbse.com/2009/funny-exam-answers-school-students
http://download.cnet.com/TheCalcMan/3000-2094_4-10958266.html
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TheMrProgrammer wrote: I think it will be faster to iterate through the string array rather than
iterating through the database, thats why i load it in a string array. am I correct in thinking so?
No. A simple DB query with required filter in where condition will be faster than iterating an array. As I said, in worst case, searches in arrays takes O(n) time. This becomes pretty slow when you have huge number of data. Databases are clever to handle searches and can perform well than a linear storage like array.
TheMrProgrammer wrote: because the app needs to iterate through the data many times.
If you still need data in memory, load it to a right data structure that supports faster searches. You can try a SortedList which will do searches in O(log n) time as it uses binary search internally. This can improve the search time drastically.
If you have 2 million unique strings, HashSet(T) is also a good choice. It uses hash tables internally and searches are done in constant (O(1)) time.
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TheMrProgrammer wrote: I think it will be faster to iterate through the string array rather than
iterating through the database, thats why i load it in a string array. am I correct in thinking so?
If by iterating you mean you will need each row once, then loading them all at once is the worst thing you could do.
TheMrProgrammer wrote: Is there a way to have the strings in the memory, without eating up the RAM?
Magic powder perhaps.
Luc Pattyn
Have a look at my entry for the lean-and-mean competition; please provide comments, feedback, discussion, and don’t forget to vote for it! Thank you.
Local announcement (Antwerp region): Lange Wapper? Neen!
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Luc Pattyn wrote:
Magic powder perhaps.
You are wrong! Magic powder sits out of managed heap and there is no way for it to reduce memory allocated for managed strings.
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If I were you I would check into how to call garbage collection more often or call it explicitly. Also something you might find useful is the use of memory pressure.
Thanks,
Humble Programmer
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Hello Everbody,
M getting a problem on textBox Keypress.When i pass 1st Character in textBox on keypress it takes textBox.text="" value.Can Anybody provide Solution to the problem please its menance bug.
Thanks in advance
Thanks Christian Graus
Problem [Solved]
modified on Saturday, September 12, 2009 3:45 AM
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The keypress event allows you to block the text from going on to the textbox, Handle the keyup event instead, if you want the key's contents to already be reflected in the textboxes contents. It's not a bug, at all.
(edit) as I think about it, the textchanged event is the one you want, if you want to know when the text in the textbox changes.
Christian Graus
Driven to the arms of OSX by Vista.
Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
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use KeyUp event.
Keypreess fires just before the Text is changed. ![Rose | [Rose]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/rose.gif)
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After scouring the net for info on using VB.net to generate graphic output, specifically a series of rectangles at mathematically derived intervals (a lattice, in fact), I'm now wondering if it's the best way to go. I've found nothing that demonstrates what I'm trying to do. I'm just starting out on a long, long road which I've been meaning to start on for a few years. I'd like to be able to create utilities as needed some day but wanted to start with this project to get going. Is VB (and GDI+) a bad choice for this type of work? I've made spreadsheets to do the math of laying out lattices but seeing them is just as important. Steer me in the right direction if there's a better way to go. I chose VB based on my thinking it's a relatively easy way to quickly get into programming.
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Member 4196521 wrote: Is VB (and GDI+) a bad choice for this type of work?
Not even remotely. It's the most trivial way I can see of doing it in a meaningful language. You just handle the paint event of your form, and you're passed a Graphics object. This object has methods for drawing shapes onto the form, using other objects like Brushes and Pens.
I think your best bet is to look at the MSDN for help on the Graphics object, I suspect that once you know that's where to look, you'll find that the documentation is going to lead you from there.
Christian Graus
Driven to the arms of OSX by Vista.
Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
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Much obliged, Christian. Fears assuaged and whole bottle of eye drops at the ready. Once more unto the breach..
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By all means, ask more specific questions if you still get stuck, but I think that's the boost you needed to get you on your way.
One thing, if you create any brushes, etc, they need to be disposed of, you call Dispose() on them, after using them. Using a system brush like Brushes.Black, does not have this requirement. Nor should you Dispose of the graphics object passed to you on the event args, although if you ever create your own, you should dispose of them, too.
Christian Graus
Driven to the arms of OSX by Vista.
Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.
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Uncanny timing, I had just read about 'dispose' on MSDN. Too soon to tell if I will be using a brush or coordinate points-to-lines to create filled rectangles : {, which may be far more work but seems to offer easier translation from the resultant calculations to be performed in determining spacing, typically to thousandths of inches to reduce accumulated error. The graphics don't require such precision, merely visual feedback, but no sense not using it if it's there I figure.
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Hello, I need help!!!
I have my application in visual studio 2008 (originally 2003). I use Access datbase and Cristal report Viewer to preview my reports. When I'm in the preview of a report, my whole system slow down really bad.
I have my database optimized and indexed
Any ideas what I can be doing wrong? if the problem is CR or Access.
Thanks!
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well their could be alot of reason one can guess only in my opinion you might are passing your whole tables to cr and might then will be filtering using your selection criteria which is making it slower
Best Of Regards,
SOFTDEV
If you have knowledge, let others light their candles at it
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Thanks for that fast answer.
The issuie is that the report shows up fast, but while the preview of the report (crviewer) is open the rest of the computers slow down, it sound to my like all the database were locked but not because it still working but slow.
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try to use windows task manger and see which process is consuming more cpu and memory
Best Of Regards,
SOFTDEV
If you have knowledge, let others light their candles at it
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I'll try it whan I go to my client office.
In the mean time we found out that if they leave a preview of the any report open and minimize they continue working normally, if you don’t have a preview screen open your computer start slowing down…that’s weird!
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Hi,
Is there a way that you can check the state of the left mouse button inside a timer routine? I have a mouseup event but sometimes it seems like it doesn't go into the routine when i let go of the button.
Thanks
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If you are having a handler then it should be executed when mouse up happens. Can you cite a scenario when it does not fires?
It's not necessary to be so stupid, either, but people manage it. - Christian Graus, 2009 AD
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I'm basically making my own slider.
Dim mouseheight As Integer
Dim slidepos As Integer
Dim handletop As Integer
Private Sub sliderhandle_mousedown(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderhandle.MouseDown
handletop = sliderhandle.Top
If MouseButtons = Windows.Forms.MouseButtons.Left Then
SliderTimer.Enabled = True
End If
mouseheight = MousePosition.Y
End Sub
Private Sub sliderhandle_mouseup(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderhandle.MouseUp
SliderTimer.Enabled = False
handletop = sliderhandle.Top
End Sub
Private Sub SliderTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SliderTimer.Tick
slidepos = handletop + MousePosition.Y - mouseheight
If slidepos >= EmptyBar.Bottom - 15 Then
sliderhandle.Top = EmptyBar.Bottom - 15
ElseIf slidepos <= EmptyBar.Top Then
sliderhandle.Top = EmptyBar.Top
Else
sliderhandle.Top = slidepos
End If
endTimer:
End Sub
End Class
So when i have the mouse down it is going through the timer routine and when i let go it should make sliderTimer.enabled = false
It works most of the time except for when i click and move the slider for a split second. Then what happens is it follows my mouse even though i do not have the button clicked. So i was thinking if i could check the mouse button state then i could force it to disable the timer.
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Hi,
Control.MouseButtons contains the instantaneous value you want.
if ((Control.MouseButtons & MouseButtons.Left)!=0) ... would be C# code, VB must be similar.
Luc Pattyn
Have a look at my entry for the lean-and-mean competition; please provide comments, feedback, discussion, and don’t forget to vote for it! Thank you.
Local announcement (Antwerp region): Lange Wapper? Neen!
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Sorry if this has been answered, but I couldn't find it.
I'm in VS2005 but using win7 as my os. There are problems resizing forms (strange flickers) and the new win7 "tricks" (for instance, dragging the window off the top to maximize) don't work. Do I need to recompile with VS2008 or is there another solution?
Thanks
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Works for me just fine on Win7 Ultimate
Tosch
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