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Difference between clustered and nonclustered index [duplicate]
... index). For example, if you have the query (in pseudocode)
SELECT * FROM FOO WHERE FOO.BAR = 2
You might want to put an index on FOO.BAR. A clustered index should be used on a column that will be used for sorting. A clustered index is used to sort the rows on disk, so you can only have one per t...
Should I pass a shared_ptr by reference? [duplicate]
...ht experiment. Let us define a shared pointer type SF = std::shared_ptr<Foo>. In order to consider references, rather than passing function arguments let us look at the type RSF = std::reference_wrapper<T>. That is, if we have a shared pointer SF p(std::make_shared<Foo>());, then w...
How do I vertically align something inside a span tag?
...
The flexbox way:
.foo {
display: flex;
align-items: center;
justify-content: center;
height: 50px;
}
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How to check certificate name and alias in keystore files?
... also specify it in the command:
keytool -list -keystore .keystore -alias foo
If the alias is not found, it will display an exception:
keytool error: java.lang.Exception: Alias does not exist
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Convert string in base64 to image and save on filesystem in Python
... how do you do this starting off with a non-inline str? I can't do b'foobar' because I'm not making the string inline
– Seph Reed
Jul 22 '17 at 19:22
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What do *args and **kwargs mean? [duplicate]
...with *mylist and **mydict to unpack positional and keyword arguments:
def foo(a, b, c, d):
print a, b, c, d
l = [0, 1]
d = {"d":3, "c":2}
foo(*l, **d)
Will print: 0 1 2 3
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How can I rename a field for all documents in MongoDB?
...
You can use:
db.foo.update({}, {$rename:{"name.additional":"name.last"}}, false, true);
Or to just update the docs which contain the property:
db.foo.update({"name.additional": {$exists: true}}, {$rename:{"name.additional":"name.last"}}, ...
What does void mean in C, C++, and C#?
...void in the argument list is optional. However, in C, it is NOT optional: foo() means it takes any number of parameters of any type, whereas foo(void) means it takes zero parameters.
– Adam Rosenfield
Jun 28 '09 at 5:00
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Unix shell script to truncate a large file
...ou don't actually need a command to go along with the redirection:
$ echo foo > foo.txt
$ cat foo.txt
foo
$ > foo.txt
$ cat foo.txt
$
A simple redirection all by itself will clear the file.
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history.replaceState() example?
... whatever your current location href is
window.history.replaceState( {} , 'foo', '/foo' );
console.log( window.location.href ); // oh, hey, it replaced the path with /foo
There is more to replaceState() but I don't know what exactly it is that you want to do with it.
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