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Difference between CTE and SubQuery?
...
The main advantage of the Common Table Expression (when not using it for recursive queries) is encapsulation, instead of having to declare the sub-query in every place you wish to use it, you are able to define it once, but have multiple references to it.
H...
Is < faster than
...is "borrowed" bit was usually referred to as the carry bit and would be testable by a branch instruction. A second bit called the zero bit would be set if the subtraction were identically zero which implied equality.
There were usually at least two conditional branch instructions, one to branch on ...
Rails: FATAL - Peer authentication failed for user (PG::Error)
...tly by creating a database and assigning ownership to your app's user to establish the connection. To create a new user in postgresql 9 run:
sudo -u postgres psql
set the postgresql user password if you haven't, it's just backslash password.
postgres=# \password
Create a new user and password ...
Django templates: verbose version of a choice
...n by Noah to be more universal in dealing with data and field types:
<table>
{% for item in query %}
<tr>
{% for field in fields %}
<td>{{item|human_readable:field}}</td>
{% endfor %}
</tr>
{% endfor %}
</table>
Here's the c...
Current location permission dialog disappears too quickly
...heir destination or origin. All these possible destinations are shown in a table view, so I'm getting the users co-ordinates at the same time as populating the table. The only thing is, the alert view that asks for the users location appears then disappears so quickly it's impossible to click it!
...
JavaScript + Unicode regexes
...ate, and Escape check boxes, which strike a balance between avoiding unprintable characters and minimizing the size of the regex.
Here are some common expansions of different Unicode properties:
\p{L} (Letters):
[A-Za-z\u00AA\u00B5\u00BA\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02C1\u02C6-\u02D1\u02E0-\...
When 1 px border is added to div, Div size increases, Don't want to do that
...order css property will increase all elements "outer" size, excepts tds in tables. You can get a visual idea of how this works in Firebug (discontinued), under the html->layout tab.
Just as an example, a div with a width and height of 10px and a border of 1px, will have an outer width and height...
When should an IllegalArgumentException be thrown?
...m and double price. The price for corresponding item is read from database table. I simply multiply the total number of item purchased with the price value and return the result. Although I am always sure at my end(Application end) that price field value in the table could never be negative .But wha...
Virtual functions and performance - C++
...ual is a per-function attribute. A function only needs to be defined via vtable if it's marked as virtual or if it's overriding a base class that has it as virtual. You'll often see classes that have a group of virtual functions for public interface, and then a lot of inline accessors and so on. (...
Find XOR of all numbers in a given range
...f() function calculates the XOR total run from [0, a]. Take a look at this table for 4-bit numbers:
0000 <- 0 [a]
0001 <- 1 [1]
0010 <- 3 [a+1]
0011 <- 0 [0]
0100 <- 4 [a]
0101 <- 1 [1]
0110 <- 7 [a+1]
0111 <- 0 [0]
1000 <- 8 [a]
1001 <- 1 [1]
1010 <- 11 [...