Search Results

Search found 9706 results on 389 pages for 'aggregate functions'.

Page 192/389 | < Previous Page | 188 189 190 191 192 193 194 195 196 197 198 199  | Next Page >

  • Speeding up a group by date query on a big table in postgres

    - by zaius
    I've got a table with around 20 million rows. For arguments sake, lets say there are two columns in the table - an id and a timestamp. I'm trying to get a count of the number of items per day. Here's what I have at the moment. SELECT DATE(timestamp) AS day, COUNT(*) FROM actions WHERE DATE(timestamp) >= '20100101' AND DATE(timestamp) < '20110101' GROUP BY day; Without any indices, this takes about a 30s to run on my machine. Here's the explain analyze output: GroupAggregate (cost=675462.78..676813.42 rows=46532 width=8) (actual time=24467.404..32417.643 rows=346 loops=1) -> Sort (cost=675462.78..675680.34 rows=87021 width=8) (actual time=24466.730..29071.438 rows=17321121 loops=1) Sort Key: (date("timestamp")) Sort Method: external merge Disk: 372496kB -> Seq Scan on actions (cost=0.00..667133.11 rows=87021 width=8) (actual time=1.981..12368.186 rows=17321121 loops=1) Filter: ((date("timestamp") >= '2010-01-01'::date) AND (date("timestamp") < '2011-01-01'::date)) Total runtime: 32447.762 ms Since I'm seeing a sequential scan, I tried to index on the date aggregate CREATE INDEX ON actions (DATE(timestamp)); Which cuts the speed by about 50%. HashAggregate (cost=796710.64..796716.19 rows=370 width=8) (actual time=17038.503..17038.590 rows=346 loops=1) -> Seq Scan on actions (cost=0.00..710202.27 rows=17301674 width=8) (actual time=1.745..12080.877 rows=17321121 loops=1) Filter: ((date("timestamp") >= '2010-01-01'::date) AND (date("timestamp") < '2011-01-01'::date)) Total runtime: 17038.663 ms I'm new to this whole query-optimization business, and I have no idea what to do next. Any clues how I could get this query running faster?

    Read the article

  • Can Visual Studio (should it be able to) compute a diff between any two changesets associated with a

    - by Hamish Grubijan
    Here is my use case: I start on a project XYZ, for which I create a work item, and I make frequent check-ins, easily 10-20 in total. ALL of the code changes will be code-read and code-reviewed. The change sets are not consecutive - other people check-in in-between my changes, although they are very unlikely to touch the exact same files. So ... at the en of the project I am interested in a "total diff" - as if there was a single check-in by me to complete the entire project. In theory this is computable. From the list of change sets associated with the work item, you get the list of all files that were affected. Then, the algorithm can aggregate individual diffs over each file and combine them into one. It is possible that a pure total diff is uncomputable due to the fact that someone else renamed files, or changed stuff around very closely, or in the same functions as me. I that case ... I suppose a total diff can include those changes by non-me as well, and warn me about the fact. I would find this very useful, but I do not know how to do t in practice. Can Visual Studio 2008/2010 (and/or TFS server) do it? Are there other source control systems capable of doing this? Thanks.

    Read the article

  • managing IB objects without iboutlets

    - by palominoz
    i have got 24 buttons in my project.I need to manage them but I don't want to get my MainViewController polluted by 24 declarations of pointers, properties & synthesizes. i was thinking about using buttonPushed functions and do it like: -(IBAction)buttonPushed:(id)sender{ UIbutton *button=sender; [buttons addObjectAtIndex:[sender tag]]; } my question is:is sender a pointer to the IBObject?

    Read the article

  • how do i get ajax to call after previous success is complete

    - by Alessandro
    I am currently using this ajax queuing plugin http://www.onemoretake.com/2009/10/11/ajaxqueue-and-jquery-1-3/ and it works fine, except weh ajax call 1 finishes, ajax call 2 starts that is dependent on a value that the success functions generates when ajax 1 is complete. Is there a way to start of all ajax calls when the previous call is complete and success function has been run? thanks

    Read the article

  • What's the difference between $get and $find in JavaScript?

    - by RoboShop
    Hi, I'm a .NET programmer who've just started to learn more about client side scripting, and I was wondering sometimes you use $get('value') and $find('value') and I've discovered that these are just shortcuts for document.getElementById('value') and Sys.Application.findComponent('value'), respectively. However, I still don't understand: what is the difference between these two functions in JavaScript? What exactly are they looking up/retrieving when invoked? Thanks in advance.

    Read the article

  • A scripting langauge for Windows?

    - by WhyKiki
    I work in Windows and often find the need to code some script that manipulates files or basic string manipulation. Currently, I'm doing this using PHP but having a LAMP stack for this seems overkill. I've tried things like autoHotkey but the syntax and functionality is horrific. So I'm looking for a scripting with: a) a sane syntax b) lots and lots of built-in libraries, functions, etc c) minimal setup. Preferably, I would like to code and run the script from my app launcher of choice, Executor

    Read the article

  • Any way to detect SMS to E-Mail Gateways?

    - by Paul
    I want to create a PHP app that can send text messages. There are different gateways for different email carriers. Is there any library I could use that would be able to lookup or detect which gateway to use just by passing the phone number into it? This way I can take whatever email address I get out and use PHP's email functions to send a message. Thanks in advance!

    Read the article

  • [Python] How to create a named temporary file in memory?

    - by conradlee
    I would like to use Python's tempfile module to create a temporary file that I will use for communication between processes (use of pipes is awkward). The documentation I've linked to above shows two functions that almost do what I want: tempfile.NamedTemporaryFile # For creating named tempfiles tempfile.SpooledTemporaryFile # For creating tempfiles in memory but actually I want a tempfile that is both named AND in memory. Any ideas?

    Read the article

  • Identifying if a user is in the local administrators group

    - by Adam Driscoll
    My Problem I'm using PInvoked Windows API functions to verify if a user is part of the local administrators group. I'm utilizing GetCurrentProcess, OpenProcessToken, GetTokenInformationand LookupAccountSid to verify if the user is a local admin. GetTokenInformation returns a TOKEN_GROUPS struct with an array of SID_AND_ATTRIBUTES structs. I iterate over the collection and compare the user names returned by LookupAccountSid. My problem is that, locally (or more generally on our in-house domain), this works as expected. The builtin\Administrators is located within the group membership of the current process token and my method returns true. On another domain of another developer the function returns false. The LookupAccountSid functions properly for the first 2 iterations of the TOKEN_GROUPS struct, returning None and Everyone, and then craps out complaining that "A Parameter is incorrect." What would cause only two groups to work correctly? The TOKEN_GROUPS struct indicates that there are 14 groups. I'm assuming it's the SID that is invalid. Everything that I have PInvoked I have taken from an example on the PInvoke website. The only difference is that with the LookupAccountSid I have changed the Sid parameter from a byte[] to a IntPtr because SID_AND_ATTRIBUTESis also defined with an IntPtr. Is this ok since LookupAccountSid is defined with a PSID? LookupAccountSid PInvoke [DllImport("advapi32.dll", CharSet = CharSet.Auto, SetLastError = true)] static extern bool LookupAccountSid( string lpSystemName, IntPtr Sid, StringBuilder lpName, ref uint cchName, StringBuilder ReferencedDomainName, ref uint cchReferencedDomainName, out SID_NAME_USE peUse); Where the code falls over for (int i = 0; i < usize; i++) { accountCount = 0; domainCount = 0; //Get Sizes LookupAccountSid(null, tokenGroups.Groups[i].SID, null, ref accountCount, null, ref domainCount, out snu); accountName2.EnsureCapacity((int) accountCount); domainName.EnsureCapacity((int) domainCount); if (!LookupAccountSid(null, tokenGroups.Groups[i].SID, accountName2, ref accountCount, domainName, ref domainCount, out snu)) { //Finds its way here after 2 iterations //But only in a different developers domain var error = Marshal.GetLastWin32Error(); _log.InfoFormat("Failed to look up SID's account name. {0}", new Win32Exception(error).Message); continue; } If more code is needed let me know. Any help would be greatly appreciated.

    Read the article

  • .NET coupled with MATLAB or R?

    - by Peter
    I'm writing a program in .NET that will need to utilize the statistical and data analysis functions of R or MATLAB. I have used R but am now contemplating moving to MATLAB since it has a .Net compiler while R can only interface via COM objects. Can anyone recommend going either way? I know MATLAB is infinitely more expensive than R (since R is free) but I'm thinking that may translate to an easier development cycle?

    Read the article

  • C++ int vector to c#

    - by Stefan Koenen
    I'm doing a C# project and I want to call next_permutation from the algorithm library in C++. I found the way to call c++ functions in c# but i dont know how to get vectors from c++ and use it in c# (cause next_permutation require a int vector...) this is what I'm trying at the moment: extern void NextPermutation(vector<int>& permutation) { next_permutation (permutation.begin(),permutation.end()); } [DllImport("PEDLL.dll", CallingConvention = CallingConvention.Cdecl)] private static extern void NextPermutation(IntPtr test);

    Read the article

  • I ran out of available quote symbols in javascript!

    - by Chaotic_one
    I can't believe it, but this is really happening. I ran out of available quote symbols using jquery and javascript native functions together. Can somebody help? Maybe there is yet another symbol? var t=setTimeout('$("#popupChange").html('<img src="http://servername/pdf/picture/genericThrobber.gif" />');',2000);

    Read the article

  • phpDocumentor to wiki?

    - by Mike
    My company is working on end user/developer docs using mediawiki. I'd like to take a lot of the API docs that phpdoc spit out (for specific functions/methods) and have it in wiki markup for easy transfer. Any solutions out there for getting wiki markup or wiki output from phpDoc? I've looked around and found nothing.

    Read the article

  • JavaScript date comparisons

    - by Kyle
    I am new to the lower level useful functions of JavaScript, and I find myself needing to compare two date objects, but within an hourly range. For example, if Date1 is less then two hours until (or from) Date2. How could this be done?

    Read the article

  • c++ template function compiles in header but not implementation

    - by flies
    I'm trying to learn templates and I've run into this confounding error. I'm declaring some functions in a header file and I want to make a separate implementation file where the functions will be defined. Here's the code that calls the header (dum.cpp): #include <iostream> #include <vector> #include <string> #include "dumper2.h" int main() { std::vector<int> v; for (int i=0; i<10; i++) { v.push_back(i); } test(); std::string s = ", "; dumpVector(v,s); } now, here's a working header file (dumper2.h): #include <iostream> #include <string> #include <vector> void test(); template <class T> void dumpVector( std::vector<T> v,std::string sep); template <class T> void dumpVector(std::vector<T> v, std::string sep) { typename std::vector<T>::iterator vi; vi = v.begin(); std::cout << *vi; vi++; for (;vi<v.end();vi++) { std::cout << sep << *vi ; } std::cout << "\n"; return; } with implentation (dumper2.cpp): #include <iostream> #include "dumper2.h" void test() { std::cout << "!olleh dlrow\n"; } the weird thing is that if I move the code that defines dumpVector from the .h to the .cpp file, I get the following error: g++ -c dumper2.cpp -Wall -Wno-deprecated g++ dum.cpp -o dum dumper2.o -Wall -Wno-deprecated /tmp/ccKD2e3G.o: In function `main': dum.cpp:(.text+0xce): undefined reference to `void dumpVector<int>(std::vector<int, std::allocator<int> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >)' collect2: ld returned 1 exit status make: *** [dum] Error 1 So why does it work one way and not the other? Clearly the compiler can find test(), so why can't it find dumpVector?

    Read the article

< Previous Page | 188 189 190 191 192 193 194 195 196 197 198 199  | Next Page >