Data dodania Pytanie
2017-04-22 20:04 How to speed up SQL query with date GROUP BY? »
I have a normal SQLite database table called table1 with 7 columns and of course a rowid. The first column is an custom_id number, the second is date ...
(2) odpowiedzi
2017-04-22 12:04 C++ using global variable shows 100% slower than a pointer, when using pthread? »
I've got a quite program to show the performance of 2 similar programs, both uses 2 threads to do calculation. The core difference is that one uses a ...
(0) odpowiedzi
2017-04-22 08:04 Javascript performance: reduce() vs for-loop »
I was attempting this Codewars challenge and the problem involves finding the divisors of a number and then calculating the sum of these divisors squa...
(3) odpowiedzi
2017-04-21 18:04 need help tuning hive query »
My original Query - CREATE TABLE admin.FctPrfitAmt_rpt AS SELECT rcn.* FROM (SELECT t1.* FROM (SELECT * FROM admin.FctPrfitAmt t2 WHERE t2.scenari...
(3) odpowiedzi
2017-04-21 13:04 Fast indexing and bit flipping of boolean data using Python »
Using Python, I'm running a simulation where a community of species goes through a sequential set of time steps ('scenes') in each of which extinction...
(3) odpowiedzi
2017-04-21 12:04 Using Boost.Lockfree queue is slower than using mutexes »
Until now I was using std::queue in my project. I measured the average time which a specific operation on this queue requires. The times were measur...
(1) odpowiedzi
2017-04-20 18:04 How to identify the caller function name in an AJAX or XMLHttpRequest call? »
I am trying to find out how to identify the function name which initiated the Ajax call programmatically using JavaScript or jQuery for an existing co...
(1) odpowiedzi
2017-04-20 17:04 Creating instance of Entity Framework Context slows down under load »
We noticed that some very small webservice calls were taking much longer than we expected. We did some investigation and put some timers in place and ...
(0) odpowiedzi
2017-04-20 15:04 Recommended enterprise server for build, CI and CPU intensive tasks »
I'm looking for a server capable of performing the following tasks: Build-Server (we have several developers using Microsoft Team Foundation Service...
(0) odpowiedzi
2017-04-19 12:04 How to improve query performance that compute haversine formula? »
Given a table of locations with latitudes and longitudes, which of those locations are nearest to a given location? Of course, finding distances on t...
(0) odpowiedzi
2017-04-19 11:04 Apply function to elements of dataframe »
Suppose I have the following dataframe df 1 3 Scenario1 0.001 0.05 Scenario2 0.003 0.01 Scenario3 0.001 0.042 Scenario4 ...
(2) odpowiedzi
2017-04-19 00:04 Why aren't std::count and std::find optimised to use memchr? »
I was reading sehe's answer to this question and was surprised to see sehe found using a hand written loop using std::memchr to be over 3 times faster...
(0) odpowiedzi
2017-04-18 20:04 C - Fastest way to sort a large 2D integer array »
I have a 2D array, where each row contains 6 integers that are already sorted in ascending order. Example: 1 2 3 4 5 6 6 8 9 10 13 15 1 4 5 ...
(1) odpowiedzi
2017-04-18 14:04 why is java taking long time initializing two dimensional arrays starting with the first dimension having a big size number? »
I have noticed that initializing 2D array like this case 1 :- int ar [] [] = new int [10000001][10] ; taking more time than initializing it like...
(1) odpowiedzi
2017-04-18 11:04 Efficiently compute the mean bits of many bitstrings in python / numpy? »
I have a few thousand bitstrings stored as longs. Each bitstring is 1024 bits. I would like to create an array of the ratios each bit is 1. For examp...
(2) odpowiedzi
2017-04-17 16:04 Is calling equals() on the same instance faster than on changing instances? »
Is there any reason that: public void test(Object object) { for (Object other : otherObjects) { object.equals(other); } } could be ...
(3) odpowiedzi
2017-04-17 10:04 Decimal.MinValue costs more than you expect »
Recently during profiling session one method caught my eye, which in profiler's decompiled version looked like this: public static double dec2f(Decim...
(1) odpowiedzi
2017-04-17 01:04 What is __memset_sse2 and why does it perform so many instructions? »
I have two C++ implementations of an algorithm, call them A and B. The only difference between A and B is that A uses std::unordered_map<int, int&g...
(1) odpowiedzi
2017-04-16 23:04 Theoretical evaluation of SQL query cost »
I need to evaluate a SQL query in theory by analyzing the results and the number of lines looked upon. Any link to information online is welcomed as I...
(1) odpowiedzi
2017-04-16 16:04 How to vectorize Softmax probability of a multi dimensional matrix »
I am trying to go through the assignment 1 for Stanford cs244n class. Problem 1b highly recommend optimization for the Softmax function. I managed to ...
(2) odpowiedzi
2017-04-16 14:04 Find row indices of a small array in a bigger efficiency matlab »
I have an array of size 3072 x 2 and I want to find the row indices in 150000 x 2 array. For example if we have A = 2 3 7 1 ...
(2) odpowiedzi
2017-04-15 17:04 Java code execution time issue »
I have the following code modeling a lightweight framework for a vertex in my study of network diffusion. The initial prototype was from a framework i...
(1) odpowiedzi
2017-04-15 08:04 Find depth of the nested ul/ol tags »
Given DOM tree I need to find the maximum depth of the nested ul/ol tags. For example: <ul> <li>Item: <ol> <li&gt...
(2) odpowiedzi
2017-04-15 06:04 Can I speed up this function? »
I'm trying to write John Conway's Game of Life in C, but I'm having trouble adding living cells to the board. The function I wrote to handle it is ext...
(4) odpowiedzi
2017-04-14 11:04 More Elegant way to number a list according to values »
I would like to map a list into numbers according to the values. For example: ['aa', 'b', 'b', 'c', 'aa', 'b', 'a'] -> [0, 1, 1, 2, 0, 1, 3] I'...
(5) odpowiedzi
2017-04-14 10:04 2sum performance improvement »
The file contains 1 million integers, both positive and negative (there might be some repetitions!).This is your array of integers, with the ith row o...
(1) odpowiedzi
2017-04-14 08:04 Fastest way to compare millions of rows in one table with millions of rows in another »
I want to compare two tables with million of records in each table and get match data from the comparison. To get the match data from both the tables...
(2) odpowiedzi
2017-04-14 04:04 How to handle OutOfMemoryError while working with HashMap<String, Integer> »
Before starting to explain my problem, I should mention that I am not looking for a way to increase Java heap memory. I should strictly store these ob...
(2) odpowiedzi
2017-04-13 22:04 Why is documentFragment no faster than repeated DOM access? »
I was always under the impression that rather than touching the DOM repeatedly, for performance reasons, we should use a documentFragment to append mu...
(3) odpowiedzi
2017-04-13 15:04 Is there a way to tell what verbs are more efficient »
Aside from just running strobes, or checking CPU usage at the end of a job, is there anyway for me to find out which COBOL verbs are more CPU intensiv...
(3) odpowiedzi
2017-04-13 10:04 Wrapping function arguments? »
Let's suppose that I have this function: void foo (struct1 &v1, struct2 &v2, ..., structn &vn){ //do something with a subset some of t...
(2) odpowiedzi
2017-04-12 20:04 Measure strong/weak ARC references impact - Impact on execution time »
I was wondering if (and how much) strong/weak references management have an impact on code execution, especially when freeing objects to which many cl...
(1) odpowiedzi
2017-04-12 17:04 How to speed up deserialize function in dlib »
I'm using a c++ version of dlib to extract positions of the facial landmarks in an image. I would like to reduce the execution time. Now it takes arou...
(0) odpowiedzi
2017-04-12 16:04 Why so bad the performance of the NodeJS object creation if num of props greater than 8? »
I would like to know that there are any limit in NodeJS when create an object which has more than 8 properties? I made a benchmark test and it seems i...
(1) odpowiedzi
2017-04-11 14:04 Excel - File optimisations »
I'm working with a rather large Excel document (~9MB) in size which has over 60 sheets and each containing many CUBEVALUE formulas in it. This docum...
(2) odpowiedzi