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How to speed up insertion performance in PostgreSQL
...r data.
If you're using RAID 5 or RAID 6 for direct attached storage, stop now. Back your data up, restructure your RAID array to RAID 10, and try again. RAID 5/6 are hopeless for bulk write performance - though a good RAID controller with a big cache can help.
If you have the option of using a hard...
How to perform OR condition in django queryset?
...ryset = combined_queryset.order_by('-income')
Update 2019-06-20: This is now fully documented in the Django 2.1 QuerySet API reference. More historic discussion can be found in DjangoProject ticket #21333.
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Git 'fatal: Unable to write new index file'
...een having this same problem for the last few days. Basically, without my knowledge the entire repo had been moved to a new filesystem, when I tried to run git status, it was suddenly reporting that every file in the repo had been udpated.
Possible solutions
So, after much google scouring, I tried...
Count, size, length…too many choices in Ruby?
... advise using length (or its alias size) rather than count if you want to know how many elements there are altogether.
Regarding ActiveRecord, on the other hand, there are important differences. check out this post:
Counting ActiveRecord associations: count, size or length?
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Redis key naming conventions?
...key is obvious:
toy/234
This is the unique key for the toy. The key can now be used also on client side:
{
key: "toy/234",
color: "red",
url: function () {
return API_BASE_URL + this.key;
}
}
An user requests an object with key toy/666. How to get it from Redis? A Node....
What's an elegant way to conditionally add a class to an HTML element in a view?
...eact
This technique is inspired by an add-on called classNames (formerly known as classSet) from Facebook’s React front-end framework.
Using in your Rails projects
As of now, the class_names function does not exist in Rails, but this article shows you how to add or implement it into your projec...
How to create ls in windows command prompt?
... I have installed the latest version of git for windows and the ls.exe can now be found in C:\Program Files\Git\ usr \bin
– phil
Nov 24 '16 at 6:21
...
Dynamically load a JavaScript file
...rary.js", type: "text/javascript"});
The problem here is that we do not know when the external script file is fully loaded.
We often want our dependant code on the very next line and like to write something like:
if (iNeedSomeMore) {
Script.load("myBigCodeLibrary.js"); // includes code for ...
Difference between knockout View Models declared as object literals vs functions
...removeItem = function(item) {
self.items.remove(item);
}
};
Now, if you are in the scope of an individual item and call $root.removeItem, the value of this will actually be the data being bound at that level (which would be the item). By using self in this case, you can ensure that i...
Difference between binary semaphore and mutex
.... The other(s) would wait for a subsequent one. Is the order of receiving known or guaranteed? Depends on the OS.
– Benoit
Mar 3 '14 at 16:01
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