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Fastest way to count exact number of rows in a very large table?
...tract a good estimate by using query optimization tools, table statistics, etc. In the case of PostgreSQL, for instance, you could parse the output of explain count(*) from yourtable and get a reasonably good estimate of the number of rows. Which brings me to your second question.
I have a table...
How do I print debug messages in the Google Chrome JavaScript Console?
...g work in Internet Explorer,
// We just map the function (extend for info, etc. if needed)
else {
if (!window.console.debug && typeof window.console.log !== 'undefined') {
window.console.debug = window.console.log;
}
}
// ... and create all functions we expect the console to have (t...
What rules does Pandas use to generate a view vs a copy?
...a single dtype case (which could be a 1-d for a series, a 2-d for a frame, etc). numpy may generate a view; it depends on what you are slicing; sometimes you can get a view and sometimes you can't. pandas doesn't rely on this fact at all as its not always obvious whether a view is generated. but thi...
php check if array contains all array values from another array
...
@Wrikken Can't the values get reordered during array_intersect()? I mean, ['a', 'b'] != ['b', 'a'].
– sbichenko
Oct 16 '13 at 18:57
4
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LINQ: Select an object and change some properties without creating a new object
...his allows you to know the position of the item in your list, enumeration, etc. without having to modify the existing class and then knowing whether you're at the first item in the list or the last.
foreach (Item item in this.Items
.Select((x, i) => {
x.ListIndex = i;
x.IsFirst = i =...
How to check whether dynamically attached event listener exists or not?
...ts = {};
EventTarget.prototype.addEventListener = function(name, listener, etc) {
var events = EventTarget.prototype.events;
if (events[name] == null) {
events[name] = [];
}
if (events[name].indexOf(listener) == -1) {
events[name].push(listener);
}
_addEventListener(name, liste...
NuGet auto package restore does not work with MSBuild
...d from the user's configured (and enabled) package sources, respecting the order of the package sources.
As packages are downloaded, they are unzipped into the solution's
packages folder.
If you have Nuget 2.7+ installed; it's important to pick one method for > managing Automatic Pa...
Bootstrap 3 Navbar Collapse
...ings like Composer and Grunt work files, git system files, the LESS files, etc. The full files are located in the /dist folder. You'll see folders for /css, /js, /fonts. Customizing it just gives the compiled files you selected.
– jmbertucci
Sep 16 '13 at 14:...
Will using goto leak variables?
...3) that have been constructed in
that scope are destroyed in the reverse order of their construction.
[..]
Conclusion
The above mechanisms ensure that goto doesn't let you break the language.
Of course, this doesn't automatically mean that you "should" use goto for any given problem, but i...
Opening a folder in explorer and selecting a file
...xception handling for various possible failures (rights issue, wrong path, etc)
– AFract
Aug 25 '15 at 17:54
1
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