Search Results

Search found 13692 results on 548 pages for 'bad practices'.

Page 279/548 | < Previous Page | 275 276 277 278 279 280 281 282 283 284 285 286  | Next Page >

  • how to Install SproutCore 1.0 on Ubuntu 9.10

    - by Leif
    I am trying to intall SproutCore, but it doesn't work. I followed the instructions in How to Install SproutCore in Virtual Enviroment but after the installation I cant start sc in the commandline. So, I hope you understand, because my English is very bad... greetings, Leif

    Read the article

  • Could MacRuby / HotCocoa supplant the need to know Objective-C?

    - by frou
    I just discovered MacRuby / HotCocoa and really like the sound of what they're doing. I had essentially discounted the prospect of making Cocoa GUI applications myself because I have an aversion to spending time & effort learning yet another C-based language, Objective-C. I'm not saying it's bad, just not for me. Is it the case now, or in the probable future, that one will be able to make Cocoa GUI applications of substantial and first-class nature with MacRuby / HotCocoa alone while ignoring Objective-C completely?

    Read the article

  • Why isn't my query using any indices when I use a subquery?

    - by sfussenegger
    I have the following tables (removed columns that aren't used for my examples): CREATE TABLE `person` ( `id` int(11) NOT NULL, `name` varchar(1024) NOT NULL, `sortname` varchar(1024) NOT NULL, PRIMARY KEY (`id`), KEY `sortname` (`sortname`(255)), KEY `name` (`name`(255)) ); CREATE TABLE `personalias` ( `id` int(11) NOT NULL, `person` int(11) NOT NULL, `name` varchar(1024) NOT NULL, PRIMARY KEY (`id`), KEY `person` (`person`), KEY `name` (`name`(255)) ) Currently, I'm using this query which works just fine: select p.* from person p where name = 'John Mayer' or sortname = 'John Mayer'; mysql> explain select p.* from person p where name = 'John Mayer' or sortname = 'John Mayer'; +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ | 1 | SIMPLE | p | index_merge | name,sortname | name,sortname | 767,767 | NULL | 3 | Using sort_union(name,sortname); Using where | +----+-------------+-------+-------------+---------------+---------------+---------+------+------+----------------------------------------------+ 1 row in set (0.00 sec) Now I'd like to extend this query to also consider aliases. First, I've tried using a join: select p.* from person p join personalias a where p.name = 'John Mayer' or p.sortname = 'John Mayer' or a.name = 'John Mayer'; mysql> explain select p.* from person p join personalias a on p.id = a.person where p.name = 'John Mayer' or p.sortname = 'John Mayer' or a.name = 'John Mayer'; +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ | 1 | SIMPLE | a | ALL | ref,name | NULL | NULL | NULL | 87401 | Using temporary | | 1 | SIMPLE | p | eq_ref | PRIMARY,name,sortname | PRIMARY | 4 | musicbrainz.a.ref | 1 | Using where | +----+-------------+-------+--------+-----------------------+---------+---------+-------------------+-------+-----------------+ 2 rows in set (0.00 sec) This looks bad: no index, 87401 rows, using temporary. Using temporary only appears when I use distinct, but as an alias might be the same as the name, I can't really get rid of it. Next, I've tried to replace the join with a subquery: select p.* from person p where p.name = 'John Mayer' or p.sortname = 'John Mayer' or p.id in (select person from personalias a where a.name = 'John Mayer'); mysql> explain select p.* from person p where p.name = 'John Mayer' or p.sortname = 'John Mayer' or p.id in (select id from personalias a where a.name = 'John Mayer'); +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ | 1 | PRIMARY | p | ALL | name,sortname | NULL | NULL | NULL | 540309 | Using where | | 2 | DEPENDENT SUBQUERY | a | index_subquery | person,name | person | 4 | func | 1 | Using where | +----+--------------------+-------+----------------+------------------+--------+---------+------+--------+-------------+ 2 rows in set (0.00 sec) Again, this looks pretty bad: no index, 540309 rows. Interestingly, both queries (select p.* from person ... or p.id in (4711,12345) and select id from personalias a where a.name = 'John Mayer') work extremely well. Why doesn't MySQL use any indices for both of my queries? What else could I do? Currently, it looks best to fetch person.ids for aliases and add them statically as an in(...) to the second query. There certainly has to be another way to do this with a single query. I'm currently out of ideas though. Could I somehow force MySQL into using another (better) query plan?

    Read the article

  • Singleton: How should it be used

    - by Loki Astari
    Edit: From another question I provided an answer that has links to a lot of questions/answers about singeltons: More info about singletons here: So I have read the thread Singletons: good design or a crutch? And the argument still rages. I see Singletons as a Design Pattern (good and bad). The problem with Singleton is not the Pattern but rather the users (sorry everybody). Everybody and their father thinks they can implement one correctly (and from the many interviews I have done, most people can't). Also because everybody thinks they can implement a correct Singleton they abuse the Pattern and use it in situations that are not appropriate (replacing global variables with Singletons!). So the main questions that need to be answered are: When should you use a Singleton How do you implement a Singleton correctly My hope for this article is that we can collect together in a single place (rather than having to google and search multiple sites) an authoritative source of when (and then how) to use a Singleton correctly. Also appropriate would be a list of Anti-Usages and common bad implementations explaining why they fail to work and for good implementations their weaknesses. So get the ball rolling: I will hold my hand up and say this is what I use but probably has problems. I like "Scott Myers" handling of the subject in his books "Effective C++" Good Situations to use Singletons (not many): Logging frameworks Thread recycling pools /* * C++ Singleton * Limitation: Single Threaded Design * See: http://www.aristeia.com/Papers/DDJ_Jul_Aug_2004_revised.pdf * For problems associated with locking in multi threaded applications * * Limitation: * If you use this Singleton (A) within a destructor of another Singleton (B) * This Singleton (A) must be fully constructed before the constructor of (B) * is called. */ class MySingleton { private: // Private Constructor MySingleton(); // Stop the compiler generating methods of copy the object MySingleton(MySingleton const& copy); // Not Implemented MySingleton& operator=(MySingleton const& copy); // Not Implemented public: static MySingleton& getInstance() { // The only instance // Guaranteed to be lazy initialized // Guaranteed that it will be destroyed correctly static MySingleton instance; return instance; } }; OK. Lets get some criticism and other implementations together. :-)

    Read the article

  • Best way to handle multiple tables to replace one big table in Rails? (e.g. 'Books1', 'Books2', etc.

    - by mikep
    Hello, I've decided to use multiple tables for an entity (e.g. Books1, Books2, Books3, etc.), instead of just one main table which could end up having a lot of rows (e.g. just Books). I'm doing this to try and to avoid a potential future performance drop that could come with having too many rows in one table. With that, I'm looking for a good way to handle this in Rails, mainly by trying to avoid loading a bunch of unused associations. (I know that I could use a partition for this, but, for now, I've decided to go the 'multiple tables' route.) Each user has their books placed into a specific table. The actual book table is chosen when the user is created, and all of their books go into the same table. I'm going to split the adds across the tables. The goal is to try and keep each table pretty much even -- but that's a different issue. One thing I don't particularly want to have is a bunch of unused associations in the User class. Right now, it looks like I'd have to do the following: class User < ActiveRecord::Base has_many :books1, :books2, :books3, :books4, :books5 end class Books1 < ActiveRecord::Base belongs_to :user end class Books2 < ActiveRecord::Base belongs_to :user end class Books3 < ActiveRecord::Base belongs_to :user end I'm assuming that the main performance hit would come in terms of memory and possibly some method call overhead for each User object, since it has to load all of those associations, which in turn creates all of those nice, dynamic model accessor methods like User.find_by_. But for each specific user, only one of the book tables would be usable/applicable, since all of a user's books are stored in the same table. So, only one of the associations would be in use at any time and any other has_many :bookX association that was loaded would be a waste. For example, with a user.id of 2, I'd only need books3.find_by_author('Author'), but the way I'm thinking of setting this up, I'd still have access to Books1..n. I don't really know Ruby/Rails does internally with all of those has_many associations though, so maybe it's not so bad. But right now I'm thinking that it's really wasteful, and that there may just be a better, more efficient way of doing this. So, a few questions: 1) Is there's some sort of special Ruby/Rails methodology that could be applied to this 'multiple tables to represent one entity' scheme? Are there any 'best practices' for this? 2) Is it really bad to have so many unused has_many associations for each object? Is there a better way to do this? 3) Does anyone have any advice on how to abstract the fact that there's multiple book tables behind a single books model/class? For example, so I can call books.find_by_author('Author') instead of books3.find_by_author('Author'). Thank you!

    Read the article

  • Standalone firewall + antivirus or combined security tools?

    - by pukipuki
    For years I'm using some antivirus software and different firewall. Now every antiviruses have got some firewall features and there are complete "internet security" complexes... and every firewall get some antivirus functionality and there are "internet security" versions. Firstly, it is hard and sometimes impossible to install and use standalone AV and FW. Sometimes I can't avoid them (i can't install KAV2010 without removing Outpost firewall etc). Secondly, complex solutions have some disbalance. Farewall from famous antivirus-brand is so user-friendly that is not suitable for me (lack of details in Norton Internet Security for example) and antiviruses from famous firewall-brands are still weak, it is proved by tests. What is today best-practices in case of functionality and security?) Some internet-security complex or two standalone applications from different vendors?

    Read the article

  • Communicating between C# application and Android app via bluetooth

    - by Akki
    The android application acts as a server in this case. I have a main activity which creates a Thread to handle serverSocket and a different thread to handle the socket connection. I am using a uuid common to C# and android. I am using 32feet bluetooth library for C#. The errors i am facing are 1) My logcat shows this debug log Error while doing socket.connect()1 java.io.IOException: File descriptor in bad state Message: File descriptor in bad state Localized Message: File descriptor in bad state Received : Testing Connection Count of Thread is : 1 2) When i try to send something via C# app the second time, this exception is thrown: A first chance exception of type 'System.InvalidOperationException' occurred in System.dll System.InvalidOperationException: BeginConnect cannot be called while another asynchronous operation is in progress on the same Socket. at System.Net.Sockets.Socket.DoBeginConnect(EndPoint endPointSnapshot, SocketAddress socketAddress, LazyAsyncResult asyncResult) at System.Net.Sockets.Socket.BeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state) at InTheHand.Net.Bluetooth.Msft.SocketBluetoothClient.BeginConnect(BluetoothEndPoint remoteEP, AsyncCallback requestCallback, Object state) at InTheHand.Net.Sockets.BluetoothClient.BeginConnect(BluetoothEndPoint remoteEP, AsyncCallback requestCallback, Object state) at InTheHand.Net.Sockets.BluetoothClient.BeginConnect(BluetoothAddress address, Guid service, AsyncCallback requestCallback, Object state) at BTSyncClient.Form1.connect() in c:\users\----\documents\visual studio 2010\Projects\TestClient\TestClient\Form1.cs:line 154 I only know android application programming and i designed the C# by learning bit and pieces. FYI, My android phone is galaxy s with ICS running on it.Please point out my mistakes.. Source codes : C# Code using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Threading; using System.Net.Sockets; using InTheHand.Net.Bluetooth; using InTheHand.Windows.Forms; using InTheHand.Net.Sockets; using InTheHand.Net; namespace BTSyncClient { public partial class Form1 : Form { BluetoothClient myself; BluetoothDeviceInfo bTServerDevice; private Guid uuid = Guid.Parse("00001101-0000-1000-8000-00805F9B34FB"); bool isConnected; public Form1() { InitializeComponent(); if (BluetoothRadio.IsSupported) { myself = new BluetoothClient(); } } private void Form1_Load(object sender, EventArgs e) { } private void button1_Click(object sender, EventArgs e) { connect(); } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { try { myself.GetStream().Close(); myself.Dispose(); } catch (Exception ex) { Console.Out.WriteLine(ex); } } private void button2_Click(object sender, EventArgs e) { SelectBluetoothDeviceDialog dialog = new SelectBluetoothDeviceDialog(); DialogResult result = dialog.ShowDialog(this); if(result.Equals(DialogResult.OK)){ bTServerDevice = dialog.SelectedDevice; } } private void callback(IAsyncResult ar) { String msg = (String)ar.AsyncState; if (ar.IsCompleted) { isConnected = myself.Connected; if (myself.Connected) { UTF8Encoding encoder = new UTF8Encoding(); NetworkStream stream = myself.GetStream(); if (!stream.CanWrite) { MessageBox.Show("Stream is not Writable"); } System.IO.StreamWriter mywriter = new System.IO.StreamWriter(stream, Encoding.UTF8); mywriter.WriteLine(msg); mywriter.Flush(); } else MessageBox.Show("Damn thing isnt connected"); } } private void connect() { try { if (bTServerDevice != null) { myself.BeginConnect(bTServerDevice.DeviceAddress, uuid, new AsyncCallback(callback) , message.Text); } } catch (Exception e) { Console.Out.WriteLine(e); } } } } Server Thread import java.io.IOException; import java.util.UUID; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothServerSocket; import android.bluetooth.BluetoothSocket; import android.util.Log; public class ServerSocketThread extends Thread { private static final String TAG = "TestApp"; private BluetoothAdapter btAdapter; private BluetoothServerSocket serverSocket; private boolean stopMe; private static final UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //private static final UUID uuid = UUID.fromString("6e58c9d5-b0b6-4009-ad9b-fd9481aef9b3"); private static final String SERVICE_NAME = "TestService"; public ServerSocketThread() { stopMe = false; btAdapter = BluetoothAdapter.getDefaultAdapter(); try { serverSocket = btAdapter.listenUsingRfcommWithServiceRecord(SERVICE_NAME, uuid); } catch (IOException e) { Log.d(TAG,e.toString()); } } public void signalStop(){ stopMe = true; } public void run(){ Log.d(TAG,"In ServerThread"); BluetoothSocket socket = null; while(!stopMe){ try { socket = serverSocket.accept(); } catch (IOException e) { break; } if(socket != null){ AcceptThread newClientConnection = new AcceptThread(socket); newClientConnection.start(); } } Log.d(TAG,"Server Thread now dead"); } // Will cancel the listening socket and cause the thread to finish public void cancel(){ try { serverSocket.close(); } catch (IOException e) { } } } Accept Thread import java.io.IOException; import java.io.InputStream; import java.util.Scanner; import android.bluetooth.BluetoothSocket; import android.util.Log; public class AcceptThread extends Thread { private BluetoothSocket socket; private String TAG = "TestApp"; static int count = 0; public AcceptThread(BluetoothSocket Socket) { socket = Socket; } volatile boolean isError; String output; String error; public void run() { Log.d(TAG, "AcceptThread Started"); isError = false; try { socket.connect(); } catch (IOException e) { Log.d(TAG,"Error while doing socket.connect()"+ ++count); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } InputStream in = null; try { in = socket.getInputStream(); } catch (IOException e) { Log.d(TAG,"Error while doing socket.getInputStream()"); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } Scanner istream = new Scanner(in); if (istream.hasNextLine()) { Log.d(TAG, "Received : "+istream.nextLine()); Log.d(TAG,"Count of Thread is : " + count); } istream.close(); try { in.close(); } catch (IOException e) { Log.d(TAG,"Error while doing in.close()"); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } try { socket.close(); } catch (IOException e) { Log.d(TAG,"Error while doing socket.close()"); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } } }

    Read the article

  • Engineers are using explosives to remove hard rock outside our office building. What countermeasures should we take?

    - by Karrax
    Our building is located approx. 100 meters from the explosive charges. They happen several times per day, and really shake the entire building a lot. This is going to go on for many days and the blasts are supposed to get stronger. Our server rooms are nothing fancy; one of them has all the racks on hard concrete while the other one has a raised floor (the one which allows the cables to go beneath it). Does anyone have any tips, countermeasures or best practices for us? Currently we are thinking of the following countermeasures: Daily report of the server rooms status lights (HD lights, power supplies and so on). Nightly check disk scan on the most important servers Order in extra supply of spare harddrives Edit: Many good answers here! However one needs to be accepted. The highest voted answer at the time of this edit will get their answer accepted.

    Read the article

  • Running windows 7 on a Mac Pro

    - by Simon
    My question is simple is running windows 7 on a mac pro as the dominat OS a bad idea? im interested in starting some mac programing but still want to do windows based coding. im tossing up between a macbook pro + a desktop or just a Mac pro. Also what development tools are available for mac?

    Read the article

  • i2s0: transmitter underrun (0)

    - by tbarbe
    were doing some audio stuff and I keep seeing this in the Organizer Console. Sun May 2 20:16:48 unknown kernel[0] : i2s0: transmitter underrun (0) Are these transmitter underruns bad? I think its just when were shutting down audio input...but could a few of these cause some issues later on?

    Read the article

  • Migrating Roaming Profiles from one drive to another

    - by Jared
    As the title suggests, how can I migrate roaming profiles located in one drive (starting to fill up already) to another? Current share is like this "SVR1\Shares\UserProfiles\%username%\ But of course, this is located in C:/Shares/UserProfiles/%username%/ What do I need to do? Do I simply copy/paste into the bigger(RAID1) drive and then repoint all the profile paths (using AD Users&Computers profile properties)? What if I can point this to a different file server all together? Best practices? tips? anything you guys can suggest. Thanks!

    Read the article

  • .Net concurrency performance on client side

    - by Yaron Naveh
    I am writing a client side .Net application which is expected to use a lot of threads. I was warned that .Net performance is very bad when it comes to concurrency. While I am not writing a real-time application, I want to make sure my application is scalable (i.e. allows many threads) and somehow comparable to an equivalent cpp application. Anyone can share his experience? Anyone can refer me to a relevant benchmark?

    Read the article

  • Fullcalendar refetchEvents probem

    - by Gabriel
    Hi guys, I have the following problem. Sometimes the refetchEvents method works well but sometimes works bad (Slow fetchs). For example sometimes I have to do double click in my button for call this method for render the events correctly from my database. So my calendar is not updated correctly when I add a new event. Do you have the same issue? Any help. Thanks A lot.

    Read the article

  • Is it ethical to let users see the request headers from visitors to a url shortening service?

    - by soniiic
    I'm currently in the progress of making a url shortening service that will let the creator see the http request headers that the browser has made when visitors visit the url. The visitors won't be made aware that they are being tracked, but obviously nothing is personally identifiable. Is there anything I should be made aware of ethically or legally that makes this a bad idea?

    Read the article

  • Green System Administrator looking for helpful tips

    - by Joshua Anderson
    I have just been promoted to Systems Administrator for our product. We are designing a application that communicates with the cloud(Amazon EC2). I will be in charge of maintaining all Instances and their underlying components. So far this involves a set of load balanced services instances that connect to a central DB in a multi-tennant DB design. Im interested in what other Sys. Admins have discovered as invaluable tools or practices. Any resources provided will be greatly appreciated.

    Read the article

  • What is the problem with ODBC as a technology?

    - by Andrew Kou
    Recently Zed Shaw (a programmer who blogs) mentioned that ODBC references should be removed from the popular python book Dive into Python. I have never worked with ODBC and I just wanted to understand why ODBC is so "bad". What are the pros and cons of the technology? What alternatives are there?

    Read the article

  • Hungarian in VBA okay?

    - by KennerL90
    I don't use hungarian (str, int) prefixes in .Net, but I still find it useful in VBA, where it is more difficult to see types. Is this bad? Unnecessary? Maybe I'm missing something. I'd really appreciate any feedback. I've been wondering for a while. Thanks everybody.

    Read the article

  • C# - Winforms webBrowser

    - by user335932
    How can i pass the URL property in web browser into an if statement.... private void button2_Click(object sender, EventArgs e) { var GameStats = comboBox1.Text; if (GameStats == "BattleField: Bad Company 2") { //Make URL equal to http://statsverse.com/ } }

    Read the article

  • MKS Integrity versus SVN.

    - by Stevan Rose
    A friend of mine works in a small team where the developers (Java and .net), who currently use SVN for their source control, are about to have MKS Integrity forced upon them. My friend would like to keep an open mind but I suspect that secretly he wants to stay with SVN. Is there anyone out there who would be willing to share their experience/opinions (good, bad or indifferent) of MKS?

    Read the article

  • Who's using Ruby on Rails in production?

    - by Jekke
    I've been kicking around Ruby and the rails framework and have been considering recommending to a client-of-a-client that they use it to rebuild their site, which is currently built in very bad ASP classic that will have to be rewritten from the ground up regardless of what technology is used. One thing I'm missing from my pitch is a list of major sites using Ruby-on-Rails. Are there any yet?

    Read the article

< Previous Page | 275 276 277 278 279 280 281 282 283 284 285 286  | Next Page >