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What do Clustered and Non clustered index actually mean?

... With a clustered index the rows are stored physically on the disk in the same order as the index. Therefore, there can be only one clustered index. With a non clustered index there is a second list that has pointers to the physical rows. You can have many non clustered ind...
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Grepping a huge file (80GB) any way to speed it up?

... Here are a few options: 1) Prefix your grep command with LC_ALL=C to use the C locale instead of UTF-8. 2) Use fgrep because you're searching for a fixed string, not a regular expression. 3) Remove the -i option, if you don't need it. So your command becomes: LC_ALL=C fgrep -A 5 -...
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Cross Domain Form POSTing

I've seen articles and posts all over (including SO) on this topic, and the prevailing commentary is that same-origin policy prevents a form POST across domains. The only place I've seen someone suggest that same-origin policy does not apply to form posts, is here . ...
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Rails migration for change column

...). If it starts with "add" or "remove" then the migration will be automatically populated with code to add or remove columns, which saves you writing that code yourself. – Alex Korban Oct 26 '11 at 19:35 ...
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Why does Unicorn need to be deployed together with Nginx?

... application servers. They also know how to handle caching and are good at allowing concurrent file downloads while still taking in traffic and passing it to the application servers. – Pratik Jan 5 '12 at 9:28 ...
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Why must a nonlinear activation function be used in a backpropagation neural network? [closed]

...ion function is to introduce non-linearity into the network in turn, this allows you to model a response variable (aka target variable, class label, or score) that varies non-linearly with its explanatory variables non-linear means that the output cannot be reproduced from a linear combination of ...
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Forking vs. Branching in GitHub

...op of the branch of interest you got updated from that fetch. The rebase allows you to make sure your changes are straightforward (no merge conflict to handle), making your pulling request that more easy when you want the maintainer of the original project to include your patches in his project. ...
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Shell script - remove first and last quote (") from a variable

... @jsears Huh? This specifically trims one from the start if there is one, and one from the end if there is one. If you don't want to remove unless both are present; yes, a single sed regex could be used, or the variable substitution could be wrapped i...
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Java Class.cast() vs. cast operator

...ject) isn't special to the compiler. It could be optimized when used statically (i.e. Foo.class.cast(o) rather than cls.cast(o)) but I've never seen anybody using it - which makes the effort of building this optimization into the compiler somewhat worthless. ...
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Mutable vs immutable objects

... were based upon mutable values. Those values changed outside the map and all of the hashing became obsolete. Theorists like to harp on this point, but in practice I haven't found it to be too much of an issue. Another aspect is the logical "reasonability" of your code. This is a hard term to def...