I would like to list all artist's tracks order by track length. artists     albums        tracks ----------  ------------  ------------ id          id            id name        artist_id     album_id             name          name   or artists     albums        tracks ----------  ------------  ------------ id          id            id name        artist_id     album_id             name          artist_id                           name  Less data in the first database, but easier queries in the secont database. Which is better?
Why do database guys go on about normalisation?    What is it? How does it help?    Does it apply to anything outside of databases?
Sometimes a question I ask will get answers that don't help me, or maybe it doesn't receive any answers at all.  How about making a notification when somebody links to my question?   It could be something like this:     New information regarding your question might be available at {link}   It might help me getting an answer from related questions that weren't there when I first asked the question. How to initialize a struct in accordance with C programming language standards I want to initialize a struct element, split in declaration and initialization. This is what I have:  typedef struct MY_TYPE {   bool flag;   short int value;   double stuff; } MY_TYPE;  void function(void) {   MY_TYPE a;   ...   a = { true, 15, 0.123 } }   Is this the way to declare and initialize a local variable of MY_TYPE in accordance with C programming language standards (C89, C90, C99, C11, etc.)? Or is there anything better or at least working?  Update I ended up having a static initialization element where I set every subelement according to my needs. centered logo ok? I'm designing a website for a rather unknown software company. The company likes the design but cannnot get along with our desicion to center their logo on the top of their page, although all the other elements are centered. Therefore a left aligned logo wouldn't look good. I know, it seems all UX studies prove them right, but positioning the logo in the center isn't a unpopular practice anymore.   Furthermore I think the way we read a website has adapted the last 10 years. Are there any studies about this topic that could help prove my point?  Thanks How variance is defined? The variance of a random variable $X$ is defined as $E[(x-\mu )^2]$. Why can't it be defined as $E[|x-\mu |]$. i.e., What is the basic idea behind this definition. Thank you. Which is correct, "neither is" or "neither are"? Bob: "Can I set the font color? Can I customize the text?"  Frank: "Neither of these options is available. Sorry!"    Is "neither is" always correct or should one use "neither are" in some cases and what are the exact rules?  of this-is-why-stackexchange-exists :P When will my device get the Android 5.0 update (Lollipop)? Android 5.0 (Lollipop) was officially announced on October 15th, 2014.  You can review the high-level changes at the  and the announcement on the official .  Of course, not all devices will get this update right away and others won't get it at all. Each manufacturer and carrier often choose to add their custom modifications which tend to delay the official release.  When will each device get Android 5.0, either officially or unofficially, if ever?  See also: Can a shell script set environment variables of the calling shell? I'm using Ubuntu 11.04 and I want to free up some space in my root directory, which is overloaded. I especially want to change the path used for installing applications (they are getting installed directly to the root drive).  Another consideration is that I'm working on a MySQL database server. The server is installed in the root directory itself, so I don't want to  risk losing any data.  Please give me some tips to help sort out this problem. Why are map tiles being repeated? Using MapServer and Openlayers How to start a GUI software on a remote Linux PC via SSH Sometimes I need to start XMBC media player or other GUI software a one of my PC (small Xubuntu PC used as a media center).  Usually I do this starting a X11vnc server on the remote PC via SSH and than connecting with an Xvnc client to the Xfce desktop.  Is there a way to start a GUI software on a remote Linux PC via SSH?  Thanks! LED accent light that slowly dims when removed from power source We've all played with different transformers and power supplies that have an LED indicator that dims before going out entirely when the power supply is unplugged.  I'm working on designing an accent light which would involve a translucent crystal light source (probably made of resin or glass if I can find a cheap supplier) containing LEDs and certain electronics, and a base which would supply electrical current. For gamers, it might appear somewhat like a Welkynd Stone. My question is what is the simplest way to cause the LEDs to dim slowly (say over 2-10 seconds) when the crystal is removed from the base? Similar to the unplugged transformer, but with an intentional and controlled dimming.  I just purchased some LEDs and plan to build a test system over the next month or two. These LEDs are in a 5 meter strip divided into 3 LED series run in parallel and rated at 12v. I do not know the amp rating of the LEDs, but I'm guessing in the 20ma range (what I've read is average for bright white). I will probably use 4 series totaling 12 LEDs in the test build.   If I have the transformer from AC power built into the base, I was guessing I could use a number of capacitors in parallel with a resistor to store electricity and slowly discharge it into the LEDs. But I'm a self-taught enthusiast so I honestly don't know if this would actually work. Nor do I know the number and ratings of capacitors and resitor that I would need.  If I have the transformer built into the crystal, the transformer and rectifier would retain a small amount of electricity, but I don't think it would be nearly enough to provide the effect I'm looking for, so something else would have to be added to make it last for several seconds.  A nicad battery with control electronics is literally my last resort for achieving this effect, and I'll probably give up on the idea before I go programming my own circuit board.  That's my main question. If anyone wants to toss in some thoughts on how to connect the crystal to the base, I'm open to suggestions. My original plan was to simply have a direct copper to copper connection with the base. But I've recently been considering an EM charging system (akin to a powermat or  my dad has). The concern with the wireless is providing consistent power to the LEDs, though it is safer. I've also learned quite a bit already about constructing the power supply from perusing this SE site, but if anyone has any suggestions for that, too, I'm all ears. For the test build I'll probably hook it up to a computer power supply, or a laptop power supply if I can find a 12v one at Goodwill or the local electronics parts store.  If I get the test model to work, I plan on building possibly a dozen of these for accent lighting around my home. How can I start automatically a command on Ubuntu 18.04? I have a small command like this  xinput set-prop "XP-PEN G430S Pen Pen (0)" --type=float "Coordinate Transformation Matrix" 1.155756, 0.000000, 0.000000, 0.000000, 1.529, 0.000000, 0.000000, 0.000000, 1.000000   to use my XP-PEN tablet, I have to start it automatically every time that I start my PC. How can I do that? How to create batch file in Windows using "start" with a path and command with spaces I need to create a batch file which starts multiple console applications in a Windows .cmd file.  This can be done using the start command.  However, the command has a path in it.  I also need to pass paramaters which have spaces as well.  How to do this?  E.g. batch file  start "c:\path with spaces\app.exe" param1 "param with spaces" What happens when a Wizard loses Intelligence after preparing his spells? A Wizard prepares a number of spells equal to his Wizard level + his Intelligence modifier.  But what happens if he loses Intelligence (the most obvious way I can think of is unattuning to a Headband of intellect and having a base Intelligence score of less than 18) after preparing his spells? Does he...   Lose access to the first [INT mod lost] spells he prepared? Lose access to the last [INT mod lost] spells he prepared? Randomly lose access to [INT mod lost] of the spells he prepared? Keep access to all his prepared spells (but will be able to prepare fewer spells after his next long rest, unless he regains the lost intelligence)? Why doesn't backpropagation work when you initialize all the weight the same value (say 0.5), but works fine when given random numbers?   Shouldn't the algorithm calculate the error and work from there, despite the fact that the weights are initially the same? When adjusting the volume in Windows 8.1, a box appears at the top left corner of the screen. This box sticks around for ~13 seconds before it fades away. If you attempt to dismiss it by click on it, it switches to the music app.  How do you disable or dismiss this annoying box? At the very least, can the time visible be adjusted? More times than not, it's in the way. Which statistics to use? How can I modify the advanced search form when my hook runs too early? I'm using  to modify the content of the form on the search page &mdash; I want to remove the "phrase" and "not" fields, and restrict the "only of the types" checkboxes to a hand selected list of types.  I have the following code, which is being called and which I think should work:  function MYMODULE_form_search_form_alter(&amp;$form, &amp;$form_state, $form_id) {     unset($form['basic']);     unset($form['advanced']['keywords']['phrase']);     unset($form['advanced']['keywords']['negative']);     unset($form['advanced']['type']);     $form['advanced']['type'] = array(         '#type' =&gt; 'checkboxes',         '#title' =&gt; t('Only of the type(s)'),         '#options' =&gt; array(             'blog' =&gt; 'Blog entry',             'event' =&gt; 'Event',             'news' =&gt; 'News article'         )     );     // print_r($form);     // die; }   Except  gets to the search form after my form alter hook runs, so I don't get a chance to modify any of the form elements that it's adding.  I'm running Drupal 7.22.  How can I modify the advanced search form when my module hook runs before the hook that defines the advanced search form? How to fix byte array java.lang.NullPointerException Why won't this ocelot do anything but breed?