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Why are joins bad when considering scalability?
... its knees in production. I have seen queries that run to the order of 100,000 times faster simply by adding indexes. And that's arbitrary indexes without even doing any in-depth data analysis to determine the best mix for leftmost prefix matching.
– Duncan
Apr...
裁员！裁员！创业者们的2016“寒冬大逃杀” - 资讯 - 清泛网 - 专注IT技能提升
...在缩减成本。”
在百度搜索，关于“裁员”的新闻有263,000篇，整整38页，其中30页是发生在2016年的。
从理性上看，这是必然之举。一个美元基金合伙人对36氪说，前段时间他碰到自己投的一个创始人，对方主动和他报备说，公...
Non-Relational Database Design [closed]
... single-user applications.
For example, you can usually read a file of 10,000 records AND sort it on a field in less than half a second, an acceptable response time.
Of course, there are reasons to use a database instead of a flat file -- relational operations, data integrity, multiuser capability...
How to decide when to use Node.js?
...de.js in this case
It is very lightweight and fast. There has been over 200000 visits on this website in three weeks and minimal server resources has been able to handle it all.
The counter is really easy to make to be real time.
Node.js was easy to configure.
There are lots of modules available f...
How should I choose an authentication library for CodeIgniter? [closed]
...managed to steal 9 million items of personal information from more than 70.000 Korean web sites in one automated hack in 2008.
These attacks are not brain surgery. If you leave your back doors wide open, you shouldn't delude yourself into a false sense of security by bolting the front. Moreover, if ...
MongoDB: Combine data from multiple collections into one..how?
...e076cdf52e541d9d29"),
"isbn": "978-3-16-148999-9",
"copies_sold": 1000
}
To merge both collections is just a matter of using $lookup in the following way:
db.books.aggregate([{
$lookup: {
from: "books_selling_data",
localField: "isbn",
foreignField:...
Why does changing 0.1f to 0 slow down performance by 10x?
...p and resolve them using microcode.
If you print out the numbers after 10,000 iterations, you will see that they have converged to different values depending on whether 0 or 0.1 is used.
Here's the test code compiled on x64:
int main() {
double start = omp_get_wtime();
const float x[16]...
Algorithm for classifying words for hangman difficulty levels as “Easy”,“Medium”, or “Hard”
... English corpora.
For example, among the 1,700 six-letter words in the 10,000 most common words in Project Gutenberg as of 2006, the most difficult ten are these:
[(6, 10, 'losing', 'eaoignvwch'),
(6, 10, 'monkey', 'erdstaoync'),
(6, 10, 'pulled', 'erdaioupfh'),
(6, 10, 'slaves', 'erdsacthkl'),...
Is it better to use std::memcpy() or std::copy() in terms to performance?
...s. There is only one version of MD5, and it's faster than SHA-2, so I did 3000 loops on a similar set of 5 test strings.
These are my final 10 results:
Time (in seconds) to complete run of MD5 tests
std::copy memcpy % difference
5.52 5.56 +0.72%
5.56 5.55 -0.18%...
What are the differences between a multidimensional array and an array of arrays in C#?
...32 'value') cil managed
{
// Code size 7 (0x7)
.maxstack 8
IL_0000: ldarg.0
IL_0001: ldarg.1
IL_0002: ldelem.ref
IL_0003: ldarg.2
IL_0004: ldarg.3
IL_0005: stelem.i4
IL_0006: ret
} // end of method Program::SetElementAt
.method private hidebysig static void SetEleme...