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Storing time-series data, relational or non?
... description, the actual PK is (Device, Metric, DateTime). (Please don't call it TimeStamp, that means something else, but that is a minor issue.) The uniqueness of the row is identified by:
(Device, Metric, DateTime)
The Id column does nothing, it is totally and completely redundant.
A...
Select random lines from a file
... @MonaJalal nope just faster, since it doesn't have to compare lines at all.
– rogerdpack
May 15 '17 at 17:20
Does ...
map vs. hash_map in C++
...tied to that key.
map is implemented as a balanced binary search tree (usually a red/black tree).
An unordered_map should give slightly better performance for accessing known elements of the collection, but a map will have additional useful characteristics (e.g. it is stored in sorted order, which...
How to test equality of Swift enums with associated values
...d values.
So if you're on Swift 4.1 or newer, the following will automatically synthesize the necessary methods such that XCTAssert(t1 == t2) works. The key is to add the Equatable protocol to your enum.
enum SimpleToken: Equatable {
case Name(String)
case Number(Int)
}
let t1 = SimpleToke...
How to hash some string with sha256 in Java?
...
SHA-256 isn't an "encoding" - it's a one-way hash.
You'd basically convert the string into bytes (e.g. using text.getBytes(StandardCharsets.UTF_8)) and then hash the bytes. Note that the result of the hash would also be arbitrary binary data, and if you want to represent that in a strin...
List changes unexpectedly after assignment. How do I clone or copy it to prevent this?
...
With new_list = my_list, you don't actually have two lists. The assignment just copies the reference to the list, not the actual list, so both new_list and my_list refer to the same list after the assignment.
To actually copy the list, you have various possibilit...
Why is pow(a, d, n) so much faster than a**d % n?
...was taking so long (> 20 seconds) for midsize numbers (~7 digits). I eventually found the following line of code to be the source of the problem:
...
How do I have an enum bound combobox with custom string formatting for enum values?
...
TypeConverter. I think this is what I was looking for. All hail Simon Svensson!
[TypeConverter(typeof(EnumToStringUsingDescription))]
Enum HowNice {
[Description("Really Nice")]
ReallyNice,
[Description("Kinda Nice")]
SortOfNice,
[Description("Not Nice At All")]
NotN...
specify project file of a solution using msbuild
...and ')' with '_' in the folder name (GYP generated projects). I guess it's all the special characters are replaced with underscore.
– Maxime Viargues
Jun 13 '16 at 1:49
...
How to handle anchor hash linking in AngularJS
...croll().
Here's the (crappy) documentation.
And here's the source.
Basically you just inject it and call it in your controller, and it will scroll you to any element with the id found in $location.hash()
app.controller('TestCtrl', function($scope, $location, $anchorScroll) {
$scope.scrollTo =...