explain plan - Page 377

Windows Server 2008 R2 File Permissions

- by Fly_Trap

I’m having some problems understanding some particular file permissions behaviour. Here are the steps to reproduce: Log into the server using the default Administrator account Create a text file (testfile.txt) in C:\ProgramData containing some arbitrary text Create a new user account and make it a member of the Administrators group Log in using new account and open C:\ProgramData\testfile.txt Edit the text and try to save Upon clicking save I’m presented with the save as dialog, which indicates that i do not have the necessary permissions to edit the file. This seems odd considering that the new user account is a member of Administrators. When I view the permissions of the file I can see the there are three groups listed, System, Administrators and Users. SYSTEM and Administrators have full permissions, however, Users only has the Read & Execute and Read permissions checked. It would appear that when I open the testfile.txt from the new users account, it opens in the context of the Users group, despite being a member of Administrators, is this correct? It would certainly explain the behaviour. The reason that this is an issue for me is that if I deploy an application via 'Run as Administrator', will normal users be able to edit the text files I install to ProgramData. Is this behaviour confined to Windows server or is it the same in Vista and Win7.

Read the article

Ubuntu + virtualenv = a mess? virtualenv hates dist-packages, wants site-packages

- by lostincode

Can someone please explain to me what is going on with python in ubuntu 9.04? I'm trying to spin up virtualenv, and the --no-site-packages flag seems to do nothing with ubuntu. I installed virtualenv 1.3.3 with easy_install (which I've upgraded to setuptools 0.6c9) and everything seems to be installed to /usr/local/lib/python2.6/dist-packages I assume that when installing a package using apt-get, it's placed in /usr/lib/python2.6/dist-packages/ ? The issue is, there is a /usr/local/lib/python2.6/site-packages as well that just sits there being empty. It would seem (by looking at the path in a virtualenv) that this is the folder virtualenv uses as backup. Thus even thought I omit --no-site-packages, I cant access my local systems packages from any of my virtualenv's. So my questions are: How do I get virtualenv to point to one of the dist-packages? Which dist-packages should I point it to? /usr/lib/python2.6/dist-packages or /usr/local/lib/python2.6/dist-packages/ What is the point of /usr/lib/python2.6/site-packages? There's nothing in there! Is it first come first serve on the path? If I have a newer version of package XYZ installed in /usr/local/lib/python2.6/dist-packages/ and and older one (from ubuntu repos/apt-get) in /usr/lib/python2.6/dist-packages, which one gets imported when I import xyz? I'm assuming this is based on the path list, yes? Why the hell is this so confusing? Is there something I'm missing here? Where is it defined that easy_install should install to /usr/local/lib/python2.6/dist-packages? Will this affect pip as well? Thanks to anyone who can clear this up!

Read the article

Building "isolated" and "automatically updated" caches (java.util.List) in Java.

- by Aidos

Hi Guys, I am trying to write a framework which contains a lot of short-lived caches created from a long-living cache. These short-lived caches need to be able to return their entier contents, which is a clone from the original long-living cache. Effectively what I am trying to build is a level of transaction isolation for the short-lived caches. The user should be able to modify the contents of the short-lived cache, but changes to the long-living cache should not be propogated through (there is also a case where the changes should be pushed through, depending on the Cache type). I will do my best to try and explain: master-cache contains: [A,B,C,D,E,F] temporary-cache created with state [A,B,C,D,E,F] 1) temporary-cache adds item G: [A,B,C,D,E,F] 2) temporary-cache removes item B: [A,C,D,E,F] master-cache contains: [A,B,C,D,E,F] 3) master-cache adds items [X,Y,Z]: [A,B,C,D,E,F,X,Y,Z] temporary-cache contains: [A,C,D,E,F] Things get even harder when the values in the items can change and shouldn't always be updated (so I can't even share the underlying object instances, I need to use clones). I have implemented the simple approach of just creating a new instance of the List using the standard Collection constructor on ArrayList, however when you get out to about 200,000 items the system just runs out of memory. I know the value of 200,000 is excessive to iterate, but I am trying to stress my code a bit. I had thought that it might be able to somehow "proxy" the list, so the temporary-cache uses the master-cache, and stores all of it's changes (effectively a Memento for the change), however that quickly becomes a nightmare when you want to iterate the temporary-cache, or retrieve an item at a specific index. Also given that I want some modifications to the contents of the list to come through (depending on the type of the temporary-cache, whether it is "auto-update" or not) and I get completly out of my depth. Any pointers to techniques or data-structures or just general concepts to try and research will be greatly appreciated. Cheers, Aidos

Read the article

memcmp,strcmp,strncmp in C

- by el10780

I wrote this small piece of code in C to test memcmp() strncmp() strcmp() functions in C. Here is the code that I wrote: #include <stdio.h> #include <stdlib.h> #include <string.h> int main(int argc, char** argv) { char *word1="apple",*word2="atoms"; if (strncmp(word1,word2,5)==0) printf("strncmp result.\n"); if (memcmp(word1,word2,5)==0) printf("memcmp result.\n"); if (strcmp(word1,word2)==0) printf("strcmp result.\n"); } Can somebody explain me the differences because I am confused with these three functions?My main problem is that I have a file in which I tokenize its line of it,the problem is that when I tokenize the word "atoms" in the file I have to stop the process of tokenizing.I first tried strcmp() but unfortunately when it reached to the point where the word "atoms" were placed in the file it didn't stop and it continued,but when I used either the memcmp() or the strncmp() it stopped and I was happy.But then I thought,what if there will be a case in which there is one string in which the first 5 letters are a,t,o,m,s and these are being followed by other letters.Unfortunately,my thoughts were right as I tested it using the above code by initializing word1 to "atomsaaaaa" and word2 to atoms and memcmp() and strncmp() in the if statements returned 0.On the other hand strcmp() it didn't.It seems that I must use strcmp(). I have done google searches but I got more confused as I have seen sites and other forums to define these three differently.If it is possible for someone to give me correct explanations/definitions so I can use them correctly in my source code,I would be really grateful.

Read the article

problem with two key ranges in couchdb

- by Duasto

I'm having problem getting the right results in my coordinate system. To explain my system, I have this simple database that have x_axis, y_axis and name columns. I don't need to get all the data, I just need to display some part of it. For example, I have a coordinate system that have 10:10(meaning from x_axis -10 to 10 and from y_axis -10 to 10) and I want to display only 49 coordinates. In sql query I can do it something like this: "select * from coordinate where x_axis = -3 and x_axis <= 3 and y_axis = -3 y_axis <= 3" I tried this function but no success: "by_range": { "map": "function(doc) { emit([doc.x_axis, doc.y_axis], doc) }" } by_range?startkey=[-3,-3]&endkey=[3,3] I got a wrong results of: -3x-3 -3x-2 -3x-1 -3x0 -3x1 -3x2 -3x3 <-- should not display this part -- -3x4 -3x5 -3x6 -3x7 -3x8 -3x9 -3x10 <-- end of should not display this part -- ..... up to 3x3 to give you a better understanding of my project here is the screenshot of that I want to be made: Oops they don't allowed new poster to post an image img96(dot)imageshack(dot)us/img96/5382/coordinates(dot)jpg <<< just change the "(dot)" to "."

Read the article

Simple matrix example using C++ template class

- by skyeagle

I am trying to write a trivial Matrix class, using C++ templates in an attempt to brush up my C++, and also to explain something to a fellow coder. This is what I have som far: template class<T> class Matrix { public: Matrix(const unsigned int rows, const unsigned int cols); Matrix(const Matrix& m); Matrix& operator=(const Matrix& m); ~Matrix(); unsigned int getNumRows() const; unsigned int getNumCols() const; template <class T> T getCellValue(unsigned int row, unsigned col) const; template <class T> void setCellValue(unsigned int row, unsigned col, T value) const; private: // Note: intentionally NOT using smart pointers here ... T * m_values; }; template<class T> inline T Matrix::getCellValue(unsigned int row, unsigned col) const { } template<class T> inline void Matrix::setCellValue(unsigned int row, unsigned col, T value) { } I'm stuck on the ctor, since I need to allocate a new[] T, it seems like it needs to be a template method - however, I'm not sure I have come accross a templated ctor before. How can I implemnt the ctor?

Read the article

Eliminate full table scan due to BETWEEN (and GROUP BY)

- by Dave Jarvis

Description According to the explain command, there is a range that is causing a query to perform a full table scan (160k rows). How do I keep the range condition and reduce the scanning? I expect the culprit to be: Y.YEAR BETWEEN 1900 AND 2009 AND Code Here is the code that has the range condition (the STATION_DISTRICT is likely superfluous). SELECT COUNT(1) as MEASUREMENTS, AVG(D.AMOUNT) as AMOUNT, Y.YEAR as YEAR, MAKEDATE(Y.YEAR,1) as AMOUNT_DATE FROM CITY C, STATION S, STATION_DISTRICT SD, YEAR_REF Y FORCE INDEX(YEAR_IDX), MONTH_REF M, DAILY D WHERE -- For a specific city ... -- C.ID = 10663 AND -- Find all the stations within a specific unit radius ... -- 6371.009 * SQRT( POW(RADIANS(C.LATITUDE_DECIMAL - S.LATITUDE_DECIMAL), 2) + (COS(RADIANS(C.LATITUDE_DECIMAL + S.LATITUDE_DECIMAL) / 2) * POW(RADIANS(C.LONGITUDE_DECIMAL - S.LONGITUDE_DECIMAL), 2)) ) <= 50 AND -- Get the station district identification for the matching station. -- S.STATION_DISTRICT_ID = SD.ID AND -- Gather all known years for that station ... -- Y.STATION_DISTRICT_ID = SD.ID AND -- The data before 1900 is shaky; insufficient after 2009. -- Y.YEAR BETWEEN 1900 AND 2009 AND -- Filtered by all known months ... -- M.YEAR_REF_ID = Y.ID AND -- Whittled down by category ... -- M.CATEGORY_ID = '003' AND -- Into the valid daily climate data. -- M.ID = D.MONTH_REF_ID AND D.DAILY_FLAG_ID <> 'M' GROUP BY Y.YEAR Update The SQL is performing a full table scan, which results in MySQL performing a "copy to tmp table", as shown here: +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ | 1 | SIMPLE | C | const | PRIMARY | PRIMARY | 4 | const | 1 | | | 1 | SIMPLE | Y | range | YEAR_IDX | YEAR_IDX | 4 | NULL | 160422 | Using where | | 1 | SIMPLE | SD | eq_ref | PRIMARY | PRIMARY | 4 | climate.Y.STATION_DISTRICT_ID | 1 | Using index | | 1 | SIMPLE | S | eq_ref | PRIMARY | PRIMARY | 4 | climate.SD.ID | 1 | Using where | | 1 | SIMPLE | M | ref | PRIMARY,YEAR_REF_IDX,CATEGORY_IDX | YEAR_REF_IDX | 8 | climate.Y.ID | 54 | Using where | | 1 | SIMPLE | D | ref | INDEX | INDEX | 8 | climate.M.ID | 11 | Using where | +----+-------------+-------+--------+-----------------------------------+--------------+---------+-------------------------------+--------+-------------+ Related http://dev.mysql.com/doc/refman/5.0/en/how-to-avoid-table-scan.html http://dev.mysql.com/doc/refman/5.0/en/where-optimizations.html http://stackoverflow.com/questions/557425/optimize-sql-that-uses-between-clause Thank you!

Read the article

Why does multiple calls to xalloc result in delayed output?

- by Me myself and I

When I print the id of a stream in a single expression it prints it backwards. Normally this is what comes out: std::stringstream ss; std::cout << ss.xalloc() << '\n'; std::cout << ss.xalloc() << '\n'; std::cout << ss.xalloc(); Output is: 4 5 6 But when I do it in one expression it prints backwards, why? std::stringstream ss; std::cout << ss.xalloc() << '\n' << ss.xalloc() << '\n' << ss.xalloc(); Output: 6 5 4 I know the order of evaluation is unspecified but then why does the following always result in the correct order: std::cout << 4 << 5 << 6; Can someone explain why xalloc behaves differently? Thanks.

Read the article

What single software development tool do you think holds the most value?

- by Phobis

Every day I realize how much I love Visual Studio for .NET development.... but, I believe that Resharper, may hold a value that surpasses Visual Studio's (I am using VS 2005 for WPF/WCF development). I decided it would be great to compile a list of the most valuable tools for software development. These can be applications/plug-ins anything that you think holds GREAT value. Also, please explain the benefits of the tool that you are posting. Resharper: Intergrated Unit testing "Camel Hump" code auto completion Find "usings" (inverse of "Go to Deceleration") Code formating and member rearranging Assembly and namespace inclusion (based on your code) Check for common optimizations and possible bugs in code and suggests/rewrites the code for you (things like null checking, redundant delegate creation, inverting if statements, etc...); Tells you when code and be more generic (may suggest things like "use this interface instead" if your code never refers to something specific on an object) Helps you see code that is not being used and will clean any unused members. File structure view helps you jump around the regions of your file (this is really awesome and clean). Class searching (you can use things like camel humps) Asks you which partial file to open once you find a class. It also has it's own plugin support, so you can do things like FxCop, documentation and relfector (all free). This thing has so much I don't think I hit 10% of it yet :) [When I get time, I will try to add more... feel free to help me out]

Read the article

Using Memcached in Python/Django - questions.

- by Thomas

I am starting use Memcached to make my website faster. For constant data in my database I use this: from django.core.cache import cache cache_key = 'regions' regions = cache.get(cache_key) if result is None: """Not Found in Cache""" regions = Regions.objects.all() cache.set(cache_key, regions, 2592000) #(2592000sekund = 30 dni) return regions For seldom changed data I use signals: from django.core.cache import cache from django.db.models import signals def nuke_social_network_cache(self, instance, **kwargs): cache_key = 'networks_for_%s' % (self.instance.user_id,) cache.delete(cache_key) signals.post_save.connect(nuke_social_network_cache, sender=SocialNetworkProfile) signals.post_delete.connect(nuke_social_network_cache, sender=SocialNetworkProfile) Is it correct way? I installed django-memcached-0.1.2, which show me: Memcached Server Stats Server Keys Hits Gets Hit_Rate Traffic_In Traffic_Out Usage Uptime 127.0.0.1 15 220 276 79% 83.1 KB 364.1 KB 18.4 KB 22:21:25 Can sombody explain what columns means? And last question. I have templates where I am getting much records from a few table (relationships). So in my view I get records from one table and in templates show it and related info from others. Generating page last a few seconds for very small table (<100records). Is it some easy way to cache queries from templates? Have I to do some big structure in my view (with all related tables), cache it and send to template?

Read the article

PHP Magic faster than simply setting the class attribute?

- by Marc Trudel

Well, not exactly that, but here is an example. Can anyone explain the difference between B and C? How can it be faster to use a magic function to dynamically set a value instead of simply setting the value in the attribute definition? Here is some code: [root@vm-202-167-238-17 ~]# cat test.php; for d in A B C; do echo "------"; ./test.php $d; done; #!/usr/bin/php <?php $className = $argv[1]; class A { public function __get($a) { return 5; } } class B { public $a = 5; } class C { public function __get($a) { $this->a = 5; return 5; } } $a = new $className; $start = microtime(true); for ($i=0; $i < 1000000; $i++) $b = $a->a; $end = microtime(true); echo (($end - $start) * 1000) ." msec\n"; ------ 598.90794754028 msec ------ 205.48391342163 msec ------ 189.7759437561 msec

Read the article

friend declaration in C++

- by Happy Mittal

In Thinking in C++ by Bruce eckel, there is an example given regarding friend functions as // Declaration (incomplete type specification): struct X; struct Y { void f(X*); }; struct X { // Definition private: int i; public: friend void Y::f(X*); // Struct member friend }; void Y::f(X* x) { x->i = 47; } Now he explained this: Notice that Y::f(X*) takes the address of an X object. This is critical because the compiler always knows how to pass an address, which is of a fixed size regardless of the object being passed, even if it doesn’t have full information about the size of the type. If you try to pass the whole object, however, the compiler must see the entire structure definition of X, to know the size and how to pass it, before it allows you to declare a function such as Y::g(X). But when I tried void f(X); as declaration in struct Y, it shows no error. Please explain why?

Read the article

Function pointers to member functions

- by Jacob

There are several duplicates of this but nobody explains why I can use a member variable to store the pointer (in FOO) but when I try it with a local variable (in the commented portion of BAR), it's illegal. Could anybody explain this? #include <iostream> using namespace std; class FOO { public: int (FOO::*fptr)(int a, int b); int add_stuff(int a, int b) { return a+b; } void call_adder(int a, int b) { fptr = &FOO::add_stuff; cout<<(this->*fptr)(a,b)<<endl; } }; class BAR { public: int add_stuff(int a, int b) { return a+b; } void call_adder(int a, int b) { //int (BAR::*fptr)(int a, int b); //fptr = &BAR::add_stuff; //cout<<(*fptr)(a,b)<<endl; } }; int main() { FOO test; test.call_adder(10,20); return 0; }

Read the article

_beginthreadx and socket

- by user638197

hi, i have a question about the _beginthreadx function In the third and fourth parameter: if i have this line to create the thread hThread=(HANDLE)_beginthreadex(0,0, &RunThread, &m_socket,CREATE_SUSPENDED,&threadID ); m_socket is the socket that i want inside the thread (fourth parameter) and i have the RunThread function (third parameter) in this way static unsigned __stdcall RunThread (void* ptr) { return 0; } It is sufficient to create the thread independently if m_socket has something or not? Thanks in advance Thank you for the response Ciaran Keating helped me understand better the thread I'll explain a little more the situation I´m creating the tread in this function inside a class public: void getClientsConnection() { numberOfClients = 1; SOCKET temporalSocket = NULL; firstClient = NULL; secondClient = NULL; while (numberOfClients < 2) { temporalSocket = SOCKET_ERROR; while (temporalSocket == SOCKET_ERROR) { temporalSocket = accept(m_socket, NULL, NULL); //----------------------------------------------- HANDLE hThread; unsigned threadID; hThread=(HANDLE)_beginthreadex(0,0, &RunThread, &m_socket,CREATE_SUSPENDED,&threadID ); WaitForSingleObject( hThread, INFINITE ); if(!hThread) printf("ERROR AL CREAR EL HILO: %ld\n", WSAGetLastError()); //----------------------------------------------- } if(firstClient == NULL) { firstClient = temporalSocket; muebleC1 = temporalSocket; actionC1 = temporalSocket; ++numberOfClients; printf("CLIENTE 1 CONECTADO\n"); } else { secondClient = temporalSocket; muebleC2 = temporalSocket; actionC2 = temporalSocket; ++numberOfClients; printf("CLIENTE 2 CONECTADO\n"); } } } What i'm trying to do is to have the socket inside the thread while wait for a client connection Is this feasible as i have the code of the thread? I can change the state of the thread that is not a problem Thanks again

Read the article

Why does this Haskell code produce the "infinite type" error?

- by Charlie Flowers

I am new to Haskell and facing a "cannot construct infinite type" error that I cannot make sense of. In fact, beyond that, I have not been able to find a good explanation of what this error even means, so if you could go beyond my basic question and explain the "infinite type" error, I'd really appreciate it. Here's the code: intersperse :: a -> [[a]] -> [a] -- intersperse '*' ["foo","bar","baz","quux"] -- should produce the following: -- "foo*bar*baz*quux" -- intersperse -99 [ [1,2,3],[4,5,6],[7,8,9]] -- should produce the following: -- [1,2,3,-99,4,5,6,-99,7,8,9] intersperse _ [] = [] intersperse _ [x] = x intersperse s (x:y:xs) = x:s:y:intersperse s xs And here's the error trying to load it into the interpreter: Prelude :load ./chapter.3.ending.real.world.haskell.exercises.hs [1 of 1] Compiling Main ( chapter.3.ending.real.world.haskell.exercises.hs, interpreted ) chapter.3.ending.real.world.haskell.exercises.hs:147:0: Occurs check: cannot construct the infinite type: a = [a] When generalising the type(s) for `intersperse' Failed, modules loaded: none. Thanks. EDIT: Thanks to the responses, I have corrected the code and I also have a general guideline for dealing with the "infinite type" error in Haskell: Corrected code intersperse _ [] = [] intersperse _ [x] = x intersperse s (x:xs) = x ++ s:intersperse s xs What the problem was: My type signature states that the second parameter to intersperse is a list of lists. Therefore, when I pattern matched against "s (x:y:xs)", x and y became lists. And yet I was treating x and y as elements, not lists. Guideline for dealing with the "infinite type" error: Most of the time, when you get this error, you have forgotten the types of the various variables you're dealing with, and you have attempted to use a variable as if it were some other type than what it is. Look carefully at what type everything is versus how you're using it, and this will usually uncover the problem.

Read the article

Creating a web application that can be extended by plugins/modules

- by Adam Pope

I'm currently involved with developing a C# CMS-like web application which will be used to standardise our development of websites. From the outset, the idea has been to keep the core as simple as possible to avoid the complexity and menu/option overload that blights many CMS systems. This simple core is now complete and working very well. We envisisaged that the system would be able to accept plugins or modules which would extend the core functionality to suit a given projects needs. These would also be re-usable across projects. For example, a basic catalogue and shopping basket might be needed. All the code for such extensions should be in seperate assemblies. They should be able to provide their own admin interfaces and front-end code from this library. The system should search for available plugins and give the admin user the option to enable/disable the feature. (This is all very much like WordPress plugins) It is crucial that we attack this problem in the correct way, so I'm trying to perform as much due dilligence as possible before jumping in. I am aware of the Plugin Pattern (http://msdn.microsoft.com/en-us/library/ms972962.aspx) and have read some articles on it's use. It seems reasonable but I'm not convinced it's necessarily the correct/best technique for this situation. It seems more suited to processing applications (image/audio manipulation, maths etc). Are there any other options for achieving this kind of UI extensibility functionality? Or is the plugin pattern the way to go? I'd also be interested if anybody has links to articles that explain using the plugin pattern for this purpose?

Read the article

Multiple exports with MEF does some really heinous stuff -- why, and why is it allowed?

- by Dave

I have an interesting situation where I need to do something like this: [Export[typeof(ICandy1)] [Export[typeof(ICandy2)] public class Candy : ICandy2 { ... } where public interface ICandy1 { ... } public interface ICandy2 : ICandy1 { ... } I couldn't find any posts anywhere regarding using multiple [Export] attributes, so I figured, what the hell, might as well try it. At first glance, it actually seemed to work. I have a couple of methods that call into both interfaces of a Candy instance, and it was fine. However, as I started to test the app, I saw that the behavior wasn't right, and when looking at the Output window, I saw that I was getting tons of COMExceptions. I couldn't track down where they were all coming from, but they always occurred when a worker thread was sleeping. I figured that it had to be from the main thread, then, but didn't know how to debug this at all. Nothing should have been going on in the GUI, and I disabled my DispatchTimers just in case -- same thing. Even more strange than the COMExceptions was the really, really erratic behavior when stepping through code. About 30% of the time, when I single stepped, it would pop out of the method, or it would single step over two lines of code! Totally weird stuff that I am not used to seeing. The only thing that changed between working and non-working code was the introduction of MEF through my plugin loading code. So as a test, I changed my plugin assembly to only export one interface, and I hardcoded everything in the app that relied on the other (now not-implemented) interface. And now the COMExceptions are gone, and the weird debugging behavior is gone. Is this something people here have seen before? If MEF is not expected to allow a class to Export multiple interfaces, then shouldn't a CompositionException get raised when composing the parts? Can anyone explain why MEF would cause these weird problems???

Read the article

MySQL - What is wrong with this query or my database? Terrible performance.

- by Moss

SELECT * from `employees` a LEFT JOIN (SELECT phone1 p1, count(*) c, FROM `employees` GROUP BY phone1) b ON a.phone1 = b.p1; I'm not sure if it is this query in particular that has the problem. I have been getting terrible performance in general with this database. The table in question has 120,000 rows. I have tried this particular query remotely and locally with the MyISAM and InnoDB engines, with different types of joins, and with and without an index on phone1. I can get this to complete in about 4 minutes on a 10,000 row table successfully but performance drops exponentially with larger tables. Remotely it will lose connection to the server and locally it brings my system to its knees and seems to go on forever. This query is only a smaller step I was trying to do when a larger query couldn't complete. Maybe I should explain the whole scenario. I have one big flat ugly table that lists a bunch of people and their contact info and the info of the companies they work for. I'm trying to normalize the database and intelligently determine which phone numbers apply to individual people and which apply to an office location. My reasoning is that if a phone number occurs multiple times and the number of occurrence equals the number of times that the street address it is attached to occurs then it must be an office number. So the first step is to count each phone number grouping by phone number. Normally if you just use COUNT()...GROUP BY it will only list the first record it finds in that group so I figured I have to join the full table to the count table where the phone number matches. This does work but as I said I can't successfully complete it on any table much larger than 10,000 rows. This seems pathetic and this doesn't seem like a crazy query to do. Is there a better way to achieve what I want or do I have to break my large table into 12 pieces or is there something wrong with the table or db?

Read the article

How to map a 0..1 to 1 relationship in Entity Framework 3

- by sako73

I have two tables, Users, and Address. A the user table has a field that maps to the primary key of the address table. This field can be null. In plain english, Address exist independent of other objects. A user may be associated with one address. In the database, I have this set up as a foreign key relationship. I am attempting to map this relationship in the Entity Framework. I am getting errors on the following code: <Association Name="fk_UserAddress"> <End Role="User" Type="GenesisEntityModel.Store.User" Multiplicity="1"/> <End Role="Address" Type="GenesisEntityModel.Store.Address" Multiplicity="0..1" /> <ReferentialConstraint> <Principal Role="Address"> <PropertyRef Name="addressId"/> </Principal> <Dependent Role="User"> <PropertyRef Name="addressId"/> </Dependent> </ReferentialConstraint> </Association> It is giving a "The Lower Bound of the multiplicity must be 0" error. I would appreciate it if anyone could explain the error, and the best way to solve it. Thanks for any help.

Read the article

Does the pointer to free() have to point to beginning of the memory block, or can it point to the interior?

- by Lambert

The question is in the title... I searched but couldn't find anything. Edit: I don't really see any need to explain this, but because people think that what I'm saying makes no sense (and that I'm asking the wrong questions), here's the problem: Since people seem to be very interested in the "root" cause of all the problem rather than the actual question asked (since that apparently helps things get solved better, let's see if it does), here's the problem: I'm trying to make a D runtime library based on NTDLL.dll, so that I can use that library for subsystems other than the Win32 subsystem. So that forces me to only link with NTDLL.dll. Yes, I'm aware that the functions are "undocumented" and could change at any time (even though I'd bet a hundred dollars that wcstombs will still do the same exact thing 20 years from now, if it still exists). Yes, I know people (especially Microsoft) don't like developers linking to that library, and that I'll probably get criticized for the right here. And yes, those two points above mean that programs like chkdsk and defragmenters that run before the Win32 subsystem aren't even supposed to be created in the first place, because it's literally impossible to link with anything like kernel32.dll or msvcrt.dll and still have NT-native executables, so we developers should just pretend that those stages are meant to be forever out of our reaches. But no, I doubt that anyone here would like me to paste a few thousand lines of code and help me look through them and try to figure out why memory allocations that aren't failing are being rejected by the source code I'm modifying. So that's why I asked about a different problem than the "root" cause, even though that's supposedly known to be the best practice by the community. If things still don't make sense, feel free to post comments below! :)

Read the article

Assigning a value to a variable gets stored in the wrong spot?

- by scribbloid

Hello, I'm relatively new to C, and this is baffling me right now. It's part of a much larger program, but I've written this little program to depict the problem I'm having. #include <stdio.h> int main() { signed int tcodes[3][1]; tcodes[0][0] = 0; tcodes[0][1] = 1000; tcodes[1][0] = 1000; tcodes[1][1] = 0; tcodes[2][0] = 0; tcodes[2][1] = 1000; tcodes[3][0] = 1000; tcodes[3][1] = 0; int x, y, c; for(c = 0; c <= 3; c++) { printf("%d %d %d\r\n", c, tcodes[c][0], tcodes[c][1]); x = 20; y = 30; } } I'd expect this program to output: 0 0 1000 1 1000 0 2 0 1000 3 1000 0 But instead, I get: 0 0 1000 1 1000 0 2 0 20 3 20 30 It does this for any number assigned to x and y. For some reason x and y are overriding parts of the array in memory. Can someone explain what's going on? Thanks!

Read the article

ASP.NET: I'm getting strange output when styling a Label control...

- by pkiyan

.labelOne { border-width:thin; border-style:solid; border-color:Red; background-color:Silver; } <asp:Label ID="Label1" runat="server" CssClass="labelOne"> <h1>Hello world</h1> </asp:Label> <br /><br /> <asp:Label ID="Label2" runat="server" BorderColor="Black" BorderStyle="Solid" BorderWidth="1px" BackColor="Silver"> <h1>Hello world</h1> </asp:Label> Hello. In the code sample above I have 2 Label controls with their contents set to an h1 header tag. The first Label is styled using css, and the second with the Label's inline properties (both Labels have identical styling). But the first Label doesn't output properly, it's border is broken. If I replace the first Label's markup with plain "Hello world" text it renders properly, but it breaks again when I use markup. Can someone explain why this is happening?

Read the article

How can I store this kind of graph in neo4j for fast traversal?

- by James

This is a graph whose nodes exist in many connected components at once because a node's relationships are a collection of edge groups such that only one edge per edge group can be present at once. I need to be able to find all of the connected components that a node exists in. What would be the best way to store this graph in neo4j to quickly find all of the connected components that a node exists in? Is there a way to use the built in traversals to do this? Also: is there a name for this kind of graph? I'd appreciate any help/ideas. Update: Sorry for not being clear. All nodes are of the same type. Nodes have a variable number of edge groups. Exactly one edge from each edge group needs to be chosen for a particular connected component. I'm going to try to explain through example: Node x1 is related to: (x2 or x3 or x4) AND (x5 or x6) AND (x7) Node x2 is related to: (x8) AND (x9 or x10) So x1's first edge group is (x2, x3, x4), its second edge group is (x5, x6), and its third edge group is (x7). So here are a few connected components that x1 exists in: CC1: x1 is related to: x2, x5, x7 x2 is related to: x8 x9 CC2: x1 is related to: x2, x6, x7 x2 is related to: x8, x9 CC3: x1 is related to: x3, x5, x7 CC4: x1 is related to: x3, x6, x7 etc. I'm grateful for your help in this.

Read the article

Currently using View, Should I use a hard table instead?

- by 1001010101

Read the article

Passing Extras and screen rotation

- by Luis A. Florit

This kind of questions appear periodically. Sorry if this has been covered before, but I'm a newbie and couldn't find the appropriate answer. It deals with the correct implementation of communication between classes and activities. I made a gallery app. It has 3 main activities: the Main one, to search for filenames using a pattern; a Thumb one, that shows all the images that matched the pattern as thumbnails in a gridview, and a Photo activity, that opens a full sized image when you click a thumb in Thumbs. I pass to the Photo activity via an Intent the filenames (an array), and the position (an int) of the clicked thumb in the gridview. This third Photo activity has only one view on it: a TouchImageView, that I adapted for previous/next switching and zooming according to where you shortclick on the image (left, right or middle). Moreover, I added a longclick listener to Photo to show EXIF info. The thing is working, but I am not happy with the implementation... Some things are not right. One of the problems I am experiencing is that, if I click on the right of the image to see the next in the Photo activity, it switches fine (position++), but when rotating the device the original one at position appears. What is happening is that Photo is destroyed when rotating the image, and for some reason it restarts again, without obeying super.onCreate(savedInstanceState), loading again the Extras (the position only changed in Photo, not on the parent activities). I tried with startActivityForResult instead of startActivity, but failed... Of course I can do something contrived to save the position data, but there should be something "conceptual" that I am not understanding about how activities work, and I want to do this right. Can someone please explain me what I am doing wrong, which is the best method to implement what I want, and why? Thanks a lot!!!

Search Results

Search found 11015 results on 441 pages for 'explain plan'.

Page 377/441 | < Previous Page | 373 374 375 376 377 378 379 380 381 382 383 384 | Next Page >

- by Fly_Trap

- by lostincode

- by Aidos

- by el10780

- by Duasto

- by skyeagle

- by Dave Jarvis

- by Me myself and I

- by Phobis

- by Thomas

- by Marc Trudel

- by Happy Mittal

- by Jacob

- by user638197

- by Charlie Flowers

- by Adam Pope

- by Dave

- by Moss

- by sako73

- by Lambert

- by scribbloid

- by pkiyan

- by James

- by 1001010101

- by Luis A. Florit

< Previous Page | 373 374 375 376 377 378 379 380 381 382 383 384 | Next Page >