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MySQL vs MongoDB 1000 reads
... to perform:
One index lookup on the collection (assuming the entity is fetched by id)
Retrieve the contents of one database page (the actual binary json document)
So a b-tree lookup, and a binary page read. Log(n) + 1 IOs. If the indexes can reside entirely in memory, then 1 IO.
In MySQL with ...
How do I parse JSON with Objective-C?
... that should allow you to get the fields like activity_details, last_name, etc. from the json dictionary that is returned:
NSDictionary *userinfo=[jsondic valueforKey:@"#data"];
NSDictionary *user;
NSInteger i = 0;
NSString *skey;
if(userinfo != nil){
for( i = 0; i < [userinfo count]; i++ ) ...
How to access outer class from an inner class?
...ass_2": subclass_2}
The main code, "production ready" (without comments, etc.). Remember to replace all of each value in angle brackets (e.g. <x>) with the desired value.
class <higher_level_class>:
def __init__(self):
subclasses = self._subclass_container()
self....
Generating a drop down list of timezones with PHP
...' => 'Europe/London',
'(GMT+00:00) Greenwich Mean Time : Dublin' => 'Etc/Greenwich',
'(GMT+00:00) Lisbon' => 'Europe/Lisbon',
'(GMT+00:00) London' => 'Europe/London',
'(GMT+00:00) Monrovia' => 'Africa/Monrovia',
'(GMT+00:00) UTC' => 'UTC',
'(GMT+01:00) Amsterdam' => 'Europe/Amst...
What is an 'endpoint' in Flask?
...r Y reasons (someone refactored the code and found a more appropriate name etc...). The auto-generated endpoints by Flask helps you handle the changes of url. The explicit endpoint helps you deal with url changes and name changes of your func.
– IMCoins
Feb 20 ...
记录一些Mac OS X技巧 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...久生效的话,可以在~/.bash_profile、~/.bash_login、~/.profile或/etc/profile(需要管理员权限)里进行设置:
echo 'PS1="[\u@\h \W]\$ "' >> ~/.bash_profile
要修改主机名的话,可以打开“系统偏好设置”里的“共享”,然后编辑电脑名称。
快...
encryption/decryption with multiple keys
...o that AES-256 session key, and your recipient keys are your RSA/DSA/ECDSA/etc. assymetric key in this case.
One reason for doing it this way is that symmetric cryptographic algorithms like AES are generally a lot faster than asymmetric ones like RSA. GnuPG thus only has to encrypt ~256 bits (the ...
Enabling ProGuard in Eclipse for Android
...to be seen... Despite doing the export multiple times, restarting Eclipse, etc. Any idea why? and how to fix this? Thanks.
– Bill The Ape
Jan 6 '12 at 2:54
...
GUI not working after rewriting to MVC
...SING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(color);
g2d.fillOval(x, y, size, size);
}
@Override
public int getIconWidth() {
return size;
}
@Override
public int getIconHeight() {
...
What are the differences between Clojure, Scheme/Racket and Common Lisp?
...sp), Scheme has some modern implementations (Racket, Chicken, Chez Scheme, etc.), and Clojure was created relatively recently
Common Lisp has a built-in OO system, though it's quite different from other OO systems you might have used. Notably, it is not enforced--you don't have to write OO code.
The...
