All Questions

2
answers

How does bit shift work in C / C ++?

I'd like to understand how bit shifting works in C / C ++ . I would also like to understand how the processor performs the calculations and how it handles all of this. I have some examples in C / C ++ : void USART_Init(unsigned int ubrr0)...
asked on 22.03.2014 / 15:08
2
answers

How to serve a multi-language site in Apache?

I'm developing a website that needs to be available in 3 languages (static content only, to be served by Apache). I would like to make use of the language detection features so that the user already fell into a version compatible with the langua...
asked on 02.06.2016 / 18:34
1
answer

Free SSL Certificates Let's Encrypt have the same reliability of payments?

Encryption TLS is used by lets encrypt and uses the acme protocol that exchanges files between server-client, I realize that using https a little delay already used the paid certificate and also realized this...
asked on 14.02.2017 / 17:31
2
answers

Java memory heap

I would like to explain in a simple way what is the heap of JVM memory? I researched Google but had no clear enough answer.     
asked on 13.10.2014 / 19:29
3
answers

What is a Document Type Definition (DTD)?

How does this technology work and how does it relate to other technologies currently used, such as DOM, Xpath, and Xquery? I'm not looking for something quite thorough, an overview, how to run a DTD, and its relationship to other technologies...
asked on 08.12.2016 / 21:14
1
answer

How does C ++ padding work?

In several responses here in StackOverflow I have noticed users commenting on padding in data structures. struct { int a; char b; float d; } What is this padding (filler) that exists between the fields of a struct...
asked on 13.02.2015 / 13:29
1
answer

Real time with PHP

I am developing a system and soon I will have to start the part of interactions in real time (for notifications and chat). I am using jQuery , PHP and MySQL so far and I intend to continue with these technologies. I have a...
asked on 15.05.2015 / 22:02
1
answer

Select multiple with dynamic operation

I have a select with 4 options. These 4 options are the number of options that will appear in a multiple select. WhatIwantisassoonastheuserselectsthemostfrequentwordquantityoption,javascriptalreadyfillsthesecondselectwiththenumberofwordsselec...
asked on 27.01.2015 / 00:54
1
answer

In distributed computing how does the election of a leader work?

   Leader election is a distributed systems problem that   consensually select a process in a set of   processes with the objective of selecting a leader for a given   assignment    In distributed computing how does the election of a leader...
asked on 02.11.2016 / 09:54
4
answers

Performance of COUNT (*) and COUNT (1)

What is the difference between COUNT(1) and COUNT(*) in an SQL query. For example: SELECT COUNT(1) FROM USUARIOS; and SELECT COUNT(*) FROM USUARIOS; Is there any difference in interactions within SBGD? Which would...
asked on 20.06.2017 / 19:41