Search Results

Search found 40567 results on 1623 pages for 'database performance'.

Page 370/1623 | < Previous Page | 366 367 368 369 370 371 372 373 374 375 376 377  | Next Page >

• Generated images fail to load in browser

  - by notJim

  I've got a page on a webapp that has about 13 images that are generated by my application, which is written in the Kohana PHP framework. The images are actually graphs. They are cached so they are only generated once, but the first time the user visits the page, and the images all have to be generated, about half of the images don't load in the browser. Once the page has been requested once and images are cached, they all load successfully. Doing some ad-hoc testing, if I load an individual image in the browser, it takes from 450-700 ms to load with an empty cache (I checked this using Google Chrome's resource tracking feature). For reference, it takes around 90-150 ms to load a cached image. Even if the image cache is empty, I have the data and some of the application's startup tasks cached, so that after the first request, none of that data needs to be fetched. My questions are: Why are the images failing to load? It seems like the browser just decides not to download the image after a certain point, rather than waiting for them all to finish loading. What can I do to get them to load the first time, with an empty cache? Obviously one option is to decrease the load times, and I could figure out how to do that by profiling the app, but are there other options? As I mentioned, the app is in the Kohana PHP framework, and it's running on Apache. As an aside, I've solved this problem for now by fetching the page as soon as the data is available (it comes from a batch process), so that the images are always cached by the time the user sees them. That feels like a kludgey solution to me, though, and I'm curious about what's actually going on.

  Read the article

• update iphone application behaviour

  - by Jim

  Hi, I developed one database related application for iPhone device(SQlite database). Now i want to update that application with more features(I want to push an update for the same application). Here i am more concerned about the user data while pushing the update so my question is if i will push an update then does the update will clear all the data that is stored in .sqlite file? if this is case then how to push application update without modifying the previous data in the database file? Please suggest. Thanks, Jim.

  Read the article

• Windows Workflow runs very slowlyh on my DEV machine

  - by Joon

  I am developing an app using WF hosted in IIS as WCF services as a business layer. This runs quickly on any machine running Windows Server 2008 R2, but very slowly on our dev machines, running Windows XP SP3. Yesterday, the workflows were as fast on my dev machine as they are on the server for the whole day. Today, they are back to running slowly again (I rebooted overnight) Has anyone else experienced this problem with workflows running slowly on IIS in XP? What did you do to fix it?

  Read the article

• Update query for Access Database for certain Parameters

  - by nitinkhanna

  Hi, I am using MS Access as a database and using c#, .net for updating some records in it. But it is giving error saying "No value given for one or more required parameters." There are 5 colums in Table and I want to update only 2, for that I have written the query like "update User_DTL set user_role_id = '" + _UserRole + "', auth_id ='" + _authId + "'" + " WHERE Id = '" + _Id + "' "; where _UserRole, _authId, _Id are strings. What may be the error. Do I need to give every parameter in update statement or there is some other way. Thanks

  Read the article

• NetNamedPipe: varying response time when communication is idling

  - by Sven Künzler

  I have two WCF apps communicating one-way over named pipes. All is nice, except for one thing: Normally, the request/response cycle takes zero (marginal) time. However, if there was a time span of, say, half a minute without any communication, the request/response increases up to ~300-500ms. I looked around the net and I got the idea of using a heart beat/ping mechanism to keep the communication channel busy. Using trial and error I found that when doing a request each 10 seconds, the response times stay low. Starting at around 15s intervals, the "hiccup" response times begin to appear. Now I'm wondering where this phenomenon is originating from. I tried setting alle conceivable timeouts on both sides to 1 minute, but that did not help. Can anybody explain what's going on there?

  Read the article

• How expensive is a context switch? Is it better to implement a manual task switch than to rely on OS

  - by Vilx-

  The title says it all. Imagine I have two (three, four, whatever) tasks that have to run in parallel. Now, the easy way to do this would be to create separate threads and forget about it. But on a plain old single-core CPU that would mean a lot of context switching - and we all know that context switching is big, bad, slow, and generally simply Evil. It should be avoided, right? On that note, if I'm writing the software from ground up anyway, I could go the extra mile and implement my own task-switching. Split each task in parts, save the state inbetween, and then switch among them within a single thread. Or, if I detect that there are multiple CPU cores, I could just give each task to a separate thread and all would be well. The second solution does have the advantage of adapting to the number of available CPU cores, but will the manual task-switch really be faster than the one in the OS core? Especially if I'm trying to make the whole thing generic with a TaskManager and an ITask, etc?

  Read the article

• Populating a WPF listbox with items from an SQL (SDF) database

  - by xplinux557

  I have been searching on how to do this for a very long time, and I have not managed to get a straight answer on the subject, so hopefully one of you StackOverflow users will be able to help me here. I have a WPF ListBox named CategoryList and a SDF database called ProgramsList.sdf (with two tables called CategoryList and ProgramsList). What I wish my program to do is get the category names from the CategoryList table and list them in the ListBox control called CategoryList. Here's the code that I tried, but it only caused my program to crash. SqlConnection myConnection = new SqlConnection("Data Source=" + AppDomain.CurrentDomain.BaseDirectory + "ProgramsList.sdf"); SqlDataReader myReader = null; myConnection.Open(); CategoryList.Items.Clear(); SqlDataReader dr = new SqlCommand("SELECT Name FROM CategoryList ORDER BY Name DESC", myConnection).ExecuteReader(); while (myReader.Read()) { CategoryList.Items.Add(dr.GetInt32(0)); } myConnection.Close(); Can anyone help me? Thanks in advance!

  Read the article

• Which js lib/framework runs faster when interfacing with AppEngine?

  - by Jorge

  I'm developing a Google Maps mashup using the Python SDK, and i need to use an AJAX interface. Which lib runs faster on this combination?

  Read the article

• what can cause large discrepancy between minor GC time and total pause time?

  - by cxcg

  We have a latency-sensitive application, and are experiencing some GC-related pauses we don't fully understand. We occasionally have a minor GC that results in application pause times that are much longer than the reported GC time itself. Here is an example log snippet: 485377.257: [GC 485378.857: [ParNew: 105845K-621K(118016K), 0.0028070 secs] 136492K-31374K(1035520K), 0.0028720 secs] [Times: user=0.01 sys=0.00, real=1.61 secs] Total time for which application threads were stopped: 1.6032830 seconds The total pause time here is orders of magnitude longer than the reported GC time. These are isolated and occasional events: the immediately preceding and succeeding minor GC events do not show this large discrepancy. The process is running on a dedicated machine, with lots of free memory, 8 cores, running Red Hat Enterprise Linux ES Release 4 Update 8 with kernel 2.6.9-89.0.1EL-smp. We have observed this with (32 bit) JVM versions 1.6.0_13 and 1.6.0_18. We are running with these flags: -server -ea -Xms512m -Xmx512m -XX:+UseConcMarkSweepGC -XX:NewSize=128m -XX:MaxNewSize=128m -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCApplicationStoppedTime -XX:-TraceClassUnloading Can anybody offer some explanation as to what might be going on here, and/or some avenues for further investigation?

  Read the article

• Getting a permission error when trying to connect to sql database

  - by Matt

  I have a sql server on a dedicated machine, running SQL 2008. I have the IP of the box, a database setup on it. I've built a small script that just does a connection test, and when I run it, I get the following error. Request for the permission of type 'System.Data.SqlClient.SqlClientPermission, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed. I've been told by the admin that SQL remote access has been granted for my IP address. Anybody know what's wrong?

  Read the article

• Can serialization cause a higher memory footprint?

  - by Pentius

  Hey folks, does serialization in Java always have to shrink the memory that is used to hold an object structure? Or is it likely that serialization will have higher costs? In other words: Is serialization a tool to shrink the memory footprint of object structures in Java?

  Read the article

• checking & unchecking a HTML checkbox inside repeater based on database value

  - by subash

  i have a repeater control with item templates having check boxes,and i need the check boxes inside the repeatercontrol to be checked based on the database value of a column field "enabled" of bool type of either true or false. the code is as below what modification should i make to check and uncheck the check box? <asp:Repeater ID="rptrDashboardIssue" runat="server"> <ItemTemplate> <%issueEnum += 1;%> <div style="margin-left: -20px; position: absolute;" id="divModificationCaseflow"> <input type="checkbox" name="chkModificationCaseflow" id="chkModificationCaseflowIssue<%=issueEnum%>" checked="<%# DataBinder.Eval(Container.DataItem, "enabled")%>" /> </div> </ItemTemplate> </asp:Repeater>

  Read the article

• resort on a std::vector vs std::insert

  - by Abruzzo Forte e Gentile

  I have a sorted std::vector of relative small size ( from 5 to 20 elements ). I used std::vector since the data is continuous so I have speed because of cache. On a specific point I need to remove an element from this vector. I have now a doubt: which is the fastest way to remove this value between the 2 options below? setting that element to 0 and call sort to reorder: this has complexity but elements are on the same cache line. call erase that will copy ( or memcpy who knows?? ) all elements after it of 1 place ( I need to investigate the behind scense of erase ). Do you know which one is faster? I think that the same approach could be thought about inserting a new element without hitting the max capacity of the vector. Regards AFG

  Read the article

• Measuring the CPU frequency scaling effect

  - by Bryan Fok

  Recently I am trying to measure the effect of the cpu scaling. Is it accurate if I use this clock to measure it? template<std::intmax_t clock_freq> struct rdtsc_clock { typedef unsigned long long rep; typedef std::ratio<1, clock_freq> period; typedef std::chrono::duration<rep, period> duration; typedef std::chrono::time_point<rdtsc_clock> time_point; static const bool is_steady = true; static time_point now() noexcept { unsigned lo, hi; asm volatile("rdtsc" : "=a" (lo), "=d" (hi)); return time_point(duration(static_cast<rep>(hi) << 32 | lo)); } }; Update: According to the comment from my another post, I believe redtsc cannot use for measure the effect of cpu frequency scaling because the counter from the redtsc does not affected by the CPU frequency, am i right?

  Read the article

• Time complexity of a powerset generating function

  - by Lirik

  I'm trying to figure out the time complexity of a function that I wrote (it generates a power set for a given string): public static HashSet<string> GeneratePowerSet(string input) { HashSet<string> powerSet = new HashSet<string>(); if (string.IsNullOrEmpty(input)) return powerSet; int powSetSize = (int)Math.Pow(2.0, (double)input.Length); // Start at 1 to skip the empty string case for (int i = 1; i < powSetSize; i++) { string str = Convert.ToString(i, 2); string pset = str; for (int k = str.Length; k < input.Length; k++) { pset = "0" + pset; } string set = string.Empty; for (int j = 0; j < pset.Length; j++) { if (pset[j] == '1') { set = string.Concat(set, input[j].ToString()); } } powerSet.Add(set); } return powerSet; } So my attempt is this: let the size of the input string be n in the outer for loop, must iterate 2^n times (because the set size is 2^n). in the inner for loop, we must iterate 2*n times (at worst). 1. So Big-O would be O((2^n)*n) (since we drop the constant 2)... is that correct? And n*(2^n) is worse than n^2. if n = 4 then (4*(2^4)) = 64 (4^2) = 16 if n = 100 then (10*(2^10)) = 10240 (10^2) = 100 2. Is there a faster way to generate a power set, or is this about optimal?

  Read the article

• Fast serialization/deserialization of structs

  - by user256890

  I have huge amont of geographic data represented in simple object structure consisting only structs. All of my fields are of value type. public struct Child { readonly float X; readonly float Y; readonly int myField; } public struct Parent { readonly int id; readonly int field1; readonly int field2; readonly Child[] children; } The data is chunked up nicely to small portions of Parent[]-s. Each array contains a few thousands Parent instances. I have way too much data to keep all in memory, so I need to swap these chunks to disk back and forth. (One file would result approx. 2-300KB). What would be the most efficient way of serializing/deserializing the Parent[] to a byte[] for dumpint to disk and reading back? Concerning speed, I am particularly interested in fast deserialization, write speed is not that critical. Would simple BinarySerializer good enough? Or should I hack around with StructLayout (see accepted answer)? I am not sure if that would work with array field of Parent.children. UPDATE: Response to comments - Yes, the objects are immutable (code updated) and indeed the children field is not value type. 300KB sounds not much but I have zillions of files like that, so speed does matter.

  Read the article

• pumpevents - customized look and feel java taking too much system resources

  - by Aizaz

  I make my own GUI see here but system is taking too much resources on further looking into the issue i have found that java pumpevents method is talking too much time. Any resolutions ???? pump events more detail pump event detail

  Read the article

• Efficiently remove points with same slope

  - by Ram

  Hi, In one of mine applications I am dealing with graphics objects. I am using open source GPC library to clip/merge two shapes. To improve accuracy I am sampling (adding multiple points between two edges) existing shapes. But before displaying back the merged shape I need to remove all the points between two edges. But I am not able to find an efficient algorithm that will remove all points between two edges which has same slope with minimum CPU utilization. Currently all points are of type PointF Any pointer on this will be a great help.

  Read the article

• In Java, is there a gain in using interfaces for complex models?

  - by Gnoupi

  The title is hardly understandable, but I'm not sure how to summarize that another way. Any edit to clarify is welcome. I have been told, and recommended to use interfaces to improve performances, even in a case which doesn't especially call for the regular "interface" role. In this case, the objects are big models (in a MVC meaning), with many methods and fields. The "good use" that has been recommended to me is to create an interface, with its unique implementation. There won't be any other class implementing this interface, for sure. I have been told that this is better to do so, because it "exposes less" (or something close) to the other classes which will use methods from this class, as these objects are referring to the object from its interface (all public method from the implementation being reproduced in the interface). This seems quite strange to me, as it seems like a C++ use to me (with header files). There I see the point, but in Java? Is there really a point in making an interface for such unique implementation? I would really appreciate some clarifications on the topic, so I could justify not following such kind of behavior, and the hassle it creates from duplicating all declarations.

  Read the article

• java increase xmx dynamically at runtime

  - by Tomer

  Hi, I have a jvm server in my machine, now I want to have 2 apservers of mine sitting in same machine, however I want the standby one to have a really low amount of memory allocated with xmx because its passive, one the main server (active) goes down I want to allocate more memory to my passive server which is already up without restarting it (I have have them both having too much xmx - note they would consume memory at startup and I cant allow possibility of outOfMemory). So I want passive - low xmx once active goes down I want my passive to receive much more xmx. is there a way for me to achieve that. Thanks

  Read the article

• Using scanf() in C++ programs is faster than using cin ?

  - by zeroDivisible

  Hello, I don't know if this is true, but when I was reading FAQ on one of the problem providing sites, I found something, that poke my attention: Check your input/output methods. In C++, using cin and cout is too slow. Use these, and you will guarantee not being able to solve any problem with a decent amount of input or output. Use printf and scanf instead. Can someone please clarify this? Is really using scanf() in C++ programs faster than using cin something ? If yes, that is it a good practice to use it in C++ programs? I thought that it was C specific, though I am just learning C++...

  Read the article

• Turn database result into array

  - by Industrial

  Hi everyone, I have just made the update/add/delete part for the "Closure table" way of organizing query hierarchical data that are shown on page 70 in this slideshare: http://www.slideshare.net/billkarwin/sql-antipatterns-strike-back My database looks like this: Table Categories: ID Name 1 Top value 2 Sub value1 Table CategoryTree: child parent 1 1 2 2 2 1 However, I have a bit of an issue getting the full tree back as an multidimensional array from a single query. Here's what I would like to get back: array ( 'topvalue' = array ( 'Subvalue', 'Subvalue2', 'Subvalue3' = array ('Subvalue 1', 'Subvalue 2', 'Subvalue 3' ) ); ); Update: Found this link, but I still have a hard time to convert it into an array: http://karwin.blogspot.com/2010/03/rendering-trees-with-closure-tables.html

  Read the article

• SQL Profiler and Tuning Advisor for Reporting Services - what events should be selected?

  - by chris

  I've used the SQL Profiler to generate a trace file, and tuning advisor to take that trace file and provide some recommendations on db updates. However, the SQL Profiler doesn't seem to track the queries when running against a Reporting Server, the profiler doesn't seem to be capturing any of the queries. I'm logging the defaults (SQL:BatchCompleted and Starting, RPC:completed, and Sessions - Existing Connections) What events should I be capturing in SQL Profiler in order to run the tuning advisor?

  Read the article

• javascript and css loadings

  - by Mike

  I was wondering, If I have, let's say 6 javascripts includes on a page and 4-5 css includes as well on the same page, does it actually makes it optimal for the page to load if I do create one file or perhaps two and append them all together instead of having bunch of them?

  Read the article

• rails belongs_to sql statement using NULL id

  - by Team Pannous

  When paginating through our Phrase table it takes very long to return the results. In the sql logs we see many sql requests which don't make sense to us: Phrase Load (7.4ms) SELECT "phrases".* FROM "phrases" WHERE "phrases"."id" IS NULL LIMIT 1 User Load (0.4ms) SELECT "users".* FROM "users" WHERE "users"."id" IS NULL LIMIT 1 These add up significantly. Is there a way to prevent querying against null ids? This is the underlying model: class Phrase < ActiveRecord::Base belongs_to :user belongs_to :response, :class_name => "Phrase", :foreign_key => "next_id" end

  Read the article

< Previous Page | 366 367 368 369 370 371 372 373 374 375 376 377  | Next Page >