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What is a “Bitmap heap scan” in a query plan?
... stay in memory, but you get the point).
A bitmap index scan will sequentially open a short-list of disk pages, and grab every applicable row in each one (hence the so-called recheck cond you see in query plans).
Note, as an aside, how clustering/row order affects the associated costs with either ...
Setting the Vim background colors
... Thanks, it works. I tried that option before, but it seems that not all colors work, for instance brown and yellow options don't affect my default console background at all.
– Maksim Vi.
Jul 13 '09 at 2:52
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Is a Java hashmap search really O(1)?
...say, balanced trees, its behavior is probabilistic. In these cases its usually most helpful to talk about complexity in terms of the probability of a worst-case event occurring would be. For a hash map, that of course is the case of a collision with respect to how full the map happens to be. A co...
Getting only response header from HTTP POST using curl
... new place. If used together with -i/--include or -I/--head, headers from all requested
pages will be shown. When authentication is used, curl only sends its credentials to the initial host. If a redirect takes curl to a different
host, it won’t be able to intercept the user+pass...
How do I generate a random int number?
...ads as it's not thread safe (as is usual for any class that is not specifically made thread safe).
– Guffa
Feb 13 '18 at 17:11
11
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Shortcuts in Objective-C to concatenate NSStrings
...option has many upvotes, I think this is the best answer if you don't know all your strings upon construction. Every time you append a string, you're creating a lot of overhead. Using a mutable string removes that problem.
– Eli
Dec 22 '09 at 1:25
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What is the best way to programmatically detect porn images? [closed]
...rm of spam these days. What if I wanted something like akismet to automatically detect porn images on a social networking site which allows users to upload their pics, avatars, etc?
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JavaScript: How to pass object by value?
...
Not really.
Depending on what you actually need, one possibility may be to set o as the prototype of a new object.
var o = {};
(function(x){
var obj = Object.create( x );
obj.foo = 'foo';
obj.bar = 'bar';
})(o);
aler...
What's the best practice using a settings file in Python? [closed]
...
This is a pretty bad idea as if you want to allow low-privileged users to be able to change configuration files only, this way you're essentially allowing them to sneak in privileged code.
– nikolay
Jun 27 '12 at 23:17
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How do I run a Node.js application as its own process?
.../bin
Environment=NODE_ENV=production
WorkingDirectory=/var/www/myapp
[Install]
WantedBy=multi-user.target
Note if you're new to Unix: /var/www/myapp/app.js should have #!/usr/bin/env node on the very first line.
Copy your service file into the /etc/systemd/system folder.
Tell systemd about the ...