I have a table that does not have a primary key. This is because there is no unique field. So I created an index on SerNum, ScanDate so I could look at the table in SerNum, Scandate order. It appears as though the index is useless. When I select `WITH(INDEX ...) the results are not in the proper order. Why is this not working?  When I select with an order by SerNum, ScanDate I get  TR_SerNum   TR_Scan_Date    TR_Facility_Id  TR_Operation_Code 288470645   2015-12-04 14:39:08 95799   091 288470645   2015-12-04 18:15:53 95799   099 288470645   2015-12-06 00:42:07 95501   484 288470645   2015-12-06 23:43:54 95501   912 288470645   2015-12-07 00:16:54 95501   913 288474131   2015-11-04 06:14:37 27676   086 288474131   2015-11-29 12:38:42 73107   893 288474975   2015-11-08 13:23:13 13220   484 288474975   2015-11-09 20:30:50 13220   892 288476236   2015-09-13 01:39:44 60499   893 288476236   2015-09-13 16:27:17 60499   918 288476237   2015-08-31 18:39:45 48340   918 288476237   2015-08-31 20:00:50 48340   919 288476238   2015-09-04 12:35:19 36619   893   When I preform a select with index I get  TR_SerNum   TR_Scan_Date    TR_Facility_Id  TR_Operation_Code 288470645   2015-12-04 14:39:08 95799   091 288470645   2015-12-04 18:15:53 95799   099 288476300   2015-08-24 15:22:05 75260   918 288476300   2015-08-24 21:10:22 75260   919 288476315   2015-08-24 22:08:40 75260   918 288476862   2015-08-24 14:06:56 74141   918 288476311   2015-08-25 01:30:29 79402   919 288477203   2015-08-25 15:30:58 79402   918 288476402   2015-08-25 15:37:53 79402   918 288476515   2015-08-25 19:05:00 72231   919 288476647   2015-08-25 15:53:16 71102   919 288476522   2015-08-25 21:50:56 53714   918 288476399   2015-08-25 21:50:56 53714   918
This is a spin-off question from .   says this on the subject of storage order (clustered index) and the output order     A lot of people believe that a clustered index guarantees a sort order on output. But that's not what it does; it guarantees a storage order on disk.   See, for example, .   I've read the blog post by Hugo Kornelis and understands that an index doesn't guarantee that the sql server reads the records in a specific order. Yet I have a hard time accepting that I can't assume this for my scenario?  CREATE TABLE [dbo].[SensorValues](   [DeviceId] [int] NOT NULL,   [SensorId] [int] NOT NULL,   [SensorValue] [int] NOT NULL,   [Date] [int] NOT NULL, CONSTRAINT [PK_SensorValues] PRIMARY KEY CLUSTERED  (   [DeviceId] ASC,   [SensorId] ASC,   [Date] DESC ) WITH (     FILLFACTOR=75,     DATA_COMPRESSION = PAGE,     PAD_INDEX = OFF,     STATISTICS_NORECOMPUTE = OFF,     SORT_IN_TEMPDB = OFF,     IGNORE_DUP_KEY = OFF,     ONLINE = OFF,     ALLOW_ROW_LOCKS = ON,     ALLOW_PAGE_LOCKS = ON)   ON [MyPartitioningScheme]([Date])   My original query was this:  SELECT TOP 1 SensorValue   FROM SensorValues   WHERE SensorId = 53     AND DeviceId = 3819     AND Date &lt; 1339225010   ORDER BY Date DESC   But I suggest that I could as well use this one (read below for my explanation):  SELECT TOP 1 SensorValue   FROM SensorValues   WHERE SensorId = 53     AND DeviceId = 3819     AND Date &lt; 1339225010   As you can see, my table rows are small (16bytes) and I've got only one index, a clustered. In my scenario, the table consists of 100.000.000 records at this moment (and this will most likely increase tenfold).  When the database server queries this table it has two ways of finding my rows, either it seeks the primary key and thereby reading and returning my values in desc. order of Date, or it has to do a full table scan. My conclusion is that a full table scan on all those records will be way too slow and the database server will therefore always seek the table via its primary key and thereby returning the values sorted by Date DESC
Uniform Scattering with vector Why is saltatory conduction in myelinated axons faster than continuous conduction in unmyelinated axons? Why are American-style options worth more than European-style options? Why are American-style options worth more than European-style options?   I realize I can exercise American-style options anytime before the  expire, but I can only exercise European-style options during their  "exercise period" (usually right when they expire, but no earlier).   So it makes sense that an American option is worth at least as much as  a European option.   But why is it worth more? If I exercise my American option early, I  may make more money than waiting until expiration, but I also may make  less. Mathematically, there's no advantage, since I'm equally likely  to make as much money by waiting for expiration.   Mathematically speaking, is there ever a good reason to exercise an  American option early?   I realize people don't always behave logically, but even the formulas  that valuate options show that American options are worth more.   EDIT (answering comments):    Many of the comments people made would apply to lookback options  (), but not to American  options.  American options can do everything European options can and more. I  understand that, and that means American options can't be worth any  LESS than European options, but I'm still not clear on how you would  mathematically calculate this extra value.  @Aaronaught: "The difference between an American and European  option is the difference between getting N chances to get it right (N  being the number of days 'til expiration) and getting just one  chance. It should be easy to see why you're more likely to profit  with the former, even if you can't accurately predict price  movement."    REPLY: I don't think you really get N chances. Once you exercise the  option, that's it, no more chances. And, if you decide not to exercise  the option today, and the underlying's price falls, you can't go back  in time and exercise it yesterday.    @jdsweet: Think of it this way, if you traveled back through time  one month - with perfect knowledge of AAPL's stock price over that  period - which happens to peak viciously then return to its old price  at the end of the period - wouldn't you pay more for an American  option?    REPLY: Well, no. I'd simply buy a cheaper European option that expires  right at the spike. Or, I'd buy a European option that expires later,  and sell it when the spike occurs. American options don't give you  precognition, so you're still guessing as to when to sell/exercise.    @jdsweet: "one of the more common reasons people exercise (as  opposed to sell) an American option before expiration is if an  unexpected dividend (larger than remaining time value of the option)  was just announced that's going to be paid before the option contract  expires"    REPLY: This makes sense. I'm actually trading FOREX options, so there  is no dividend. In that scenario, are European and American options  worth the same? How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum);  Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum =  minimum + i;  Bug: randomNum can be smaller than minimum. Can I use the Google font 'Lato' for a logo design? I am creating a logo and would like to use the Google Font 'Lato', can I use this font in my logo design or are there copyright/limitations I need to worry about? I can't find anything online other than that it is an open source font that can be used in anyway you want (maybe that's my answer but I just want to make sure). Also, is it a bad idea to use a web-based font for a logo? How to make a film in black and white and add color to some objects? How is a movie made to show selective colors. For instance, in  a sister and brother are transported to the universe of an old black and white TV show, and the movie switches to being B&amp;W. Then, as the protagonists cause the inhabitants to have 'real' emotions, like fright, anger, or love, things (people, places, etc.) start having color. In the middle of the movie, many objects are still B&amp;W, yet many more are now colorized.   also used this effect (the whole film was initially shot in full color, and was converted to black-and-white. Colorization is used on certain subjects in a scene), for example.  How is this effect achieved? Is it post-production editing? What techniques might a director employ to do this? What should I focus on when converting photos to black and white? When I look at the black and white photographs from professional photographers, I notice that they have a special look. Not a specific style—obviously each photographer has her own style—but a look which make them different from similar color photos, a special feeling, which makes them shine specifically as black and white and makes color irrelevant.  When I convert my own photos to black and white in Lightroom, they don't have any special look. They just look like any other of my photos, simply converted to black and white. I imagine that there are two reasons for that:   Some scenes are better for black and white. Talented and/or experienced photographers know which scenes would be beautiful in black and white, and shoot specifically those scenes. Moreover, they know how to adapt the scene itself and the lighting to black and white (for instance by not relying on the color contrast itself).  In my case, I don't think much about shooting for black and white. It comes only in post-processing, when I either think that the photo will look great in black and white (and very often, it doesn't), or I find the colors to be poor and turn the photo to black and white (which actually doesn't make the photo any better). Post-processing is much more complex than clicking on black and white button in an app. It involves not only adjusting black and white mix (i.e. raising or lowering the lightness of specific colors), but doing lots of other adjustments.  In my case, I do black and white mix, but other adjustments I do are similar to what I would do for a color photo: actually, I may even do them on a color photo, and only then turn it to black and white.   So, what should I take in account if I want to have decent black and white photographs? Are there specific techniques, tips, tricks or warnings for someone who usually shots in color and wants to start black and white photography?  Let me show some examples. Are those scenes not great for black and white photos in the first place? Or can they be salvaged through proper post-processing?  1.  First, a poorly done photo from Scotland with dubious composition and very poor colors that I was unable to correct in Lightroom.  The same image in black and white isn't much better. The difference between the trees and the grass on the hill is barely visible. Houses on the hill fade with the sky much more than in the original version.      2.  Here's a photo of a cute pet.  In black and white, the gap between the mouse's ear and the background is barely visible. There is absolutely no benefit compared to the original.      3.  Finally, an example of a much more contrasty picture. The black and white version is weird, since the lack of color makes it difficult to understand whether the soil is the actual sand or something else. I find the sky to be weird as well, and making the blue channel darker or lighter in Lightroom haven't changed that. Too much space between full paragraph and subequations env I have a document using subequations and the parskip package. If the paragraph before a subequations environment is completely filled up to the last line, then additional vertical whitespace is introduced between this paragraph and the following subequations. I guess this is a bug, but I'm not sure, nor do I have enough TeX knowledge to try and fix it. How can I fix this whitespace issue?  Below is a MWE which shows the behaviour, at least on LaTeX2e &lt;2003/12/01> with pdfeTeX 3.141592-1.21a-2.2 (unfortunately on this machine only an old tetex distribution is installed).  \documentclass[a4paper,11pt]{article}  \usepackage{parskip} \usepackage{amsmath}  \begin{document}  The subequations environment provides a convenient way to number a foos \begin{subequations}\label{foo}   \begin{align}     x^2 + y^2 &amp;= z^2\\     a &amp;= b + c   \end{align} \end{subequations}  \end{document} The following code snippet (correctly) gives a warning in C and an error in C++ (using gcc &amp; g++ respectively, tested with versions 3.4.5 and 4.2.1; MSVC does not seem to care):  char **a; const char** b = a;   I can understand and accept this. The C++ solution to this problem is to change b to be a const char * const *, which disallows reassignment of the pointers and prevents you from circumventing const-correctness ().  char **a; const char* const* b = a;   However, in pure C, the corrected version (using const char * const *) still gives a warning, and I don't understand why. Is there a way to get around this without using a cast?  To clarify: 1) Why does this generate a warning in C?  It should be entirely const-safe, and the C++ compiler seems to recognize it as such. 2) What is the correct way to go about accepting this char** as a parameter while saying (and having the compiler enforce) that I will not be modifying the characters it points to? For example, if I wanted to write a function:  void f(const char* const* in) {   // Only reads the data from in, does not write to it }   And I wanted to invoke it on a char**, what would be the correct type for the parameter? I am trying to pass a member function within a class to a function that takes a member function class pointer.  The problem I am having is that I am not sure how to properly do this within the class using the this pointer.  Does anyone have suggestions?  Here is a copy of the class that is passing the member function:  class testMenu : public MenuScreen{ public:  bool draw;  MenuButton&lt;testMenu&gt; x;  testMenu():MenuScreen("testMenu"){     x.SetButton(100,100,TEXT("buttonNormal.png"),TEXT("buttonHover.png"),TEXT("buttonPressed.png"),100,40,&amp;this-&gt;test2);      draw = false; }  void test2(){     draw = true; } };   The function x.SetButton(...) is contained in another class, where "object" is a template.  void SetButton(int xPos, int yPos, LPCWSTR normalFilePath, LPCWSTR hoverFilePath, LPCWSTR pressedFilePath, int Width, int Height, void (object::*ButtonFunc)()) {      BUTTON::SetButton(xPos, yPos, normalFilePath, hoverFilePath, pressedFilePath, Width, Height);      this-&gt;ButtonFunc = &amp;ButtonFunc; }   If anyone has any advice on how I can properly send this function so that I can use it later. jQuery get the rendered height of an element? How do you get the rendered height of an element?  Let's say you have a &lt;div&gt; element with some content inside. This content inside is going to stretch the height of the &lt;div&gt;. How do you get the "rendered" height when you haven't explicitly set the height. Obviously, I tried:    var h = document.getElementById('someDiv').style.height;   Is there a trick for doing this? I am using jQuery if that helps. I'm currently using the below script to timestamp when an edit is made to column 7 on a sheet named "Sheet 1".  function onEdit(e) {    if ([7].indexOf(e.range.columnStart) != -1) {    e.range.offset(0, 7).setValue(new Date()).setNumberFormat("dd.MM.yyyy at HH:mm");    }   }     I have a second sheet "Sheet 2" which I need to run the same script on but against column 5.  function onEdit(e) {    if ([5].indexOf(e.range.columnStart) != -1) {    e.range.offset(0, 7).setValue(new Date()).setNumberFormat("dd.MM.yyyy at HH:mm");    }   }     I've tried .getSheetByName("Sheet1") but just cant seem to get it working correctly. Expression Versus Statement I'm asking with regards to c#, but I assume its the same in most other languages.  Does anyone have a good definition of expressions and statements and what the differences are? Does Java have buffer overflows? If $x$ and $y$ are not both $0$ then $ x^2 +xy +y^2> 0$ Add/Delete table rows dynamically using JavaScript How are pronouns resolved? Are pronouns in English resolved syntactically or semantically? Do they always refer to the closest matching noun?  A  has these examples:        We gave the bananas to the monkeys because they were hungry.   We gave the bananas to the monkeys because they were ripe.   We gave the bananas to the monkeys because they were here.       My understanding was that pronouns are resolved syntactically, and so sentence 2 is semantically incorrect (unless the author really meant that the monkeys were ripe) and sentence 3 is not ambiguous. Is this wrong?  Citations and references are most welcome. How can I find just the *.mp3 files with a recursive command like ls -R *.mp3 in a directory that contains several sub-directories and at the end copy these files in a directory that I choose.  Thanks for your support. How should I budget for ally/third party NPCs in 4e combats? I've done a few combats recently where the PCs and their enemies were not the only participants in the fight.  I wasn't sure how to budget XP in this case.  In the case of an NPC ally to the PCs, I see two options.     Draw the NPC up as a PC and increase the number of members in the party.    Draw the NPC up as an NPC and take its XP into account when budgeting.   I'm not sure if either option is correct, or if there are others.  But the ambiguity doesn't end there - what about if there's more than one side in the fight and nobody wants to team up?  I'd rather not treat it as one combat budget divided over two factions.  Unless the factions immediately unite, it's going to be an absurdly easy combat.  Would I be better off budgeting for two encounters than happen at the same time, and hoping that no PC gets ganged up on too much?  In general, how is XP budgeting done in complex combats with NPC allies and/or more than two factions? Add an SQLite database to an iPhone app