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Create an index on a huge MySQL production table without table locking
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[2017] Update: MySQL 5.6 has support for online index updates
https://dev.mysql.com/doc/refman/8.0/en/innodb-online-ddl-operations.html#online-ddl-index-syntax-notes
In MySQL 5.6 and higher, the table remains available for...
How do I get the different parts of a Flask request's url?
I want to detect if the request came from the localhost:5000 or foo.herokuapp.com host and what path was requested. How do I get this information about a Flask request?
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In Ruby how do I generate a long string of repeated text?
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310
str = "0" * 999999
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Why does parseInt yield NaN with Array#map?
...ex of the element.
In this case, you ended up calling parseInt with radix 0, 1 and 2 in turn. The first is the same as not supplying the parameter, so it defaulted based on the input (base 10, in this case). Base 1 is an impossible number base, and 3 is not a valid number in base 2:
parseInt('1'...
How do I convert a float number to a whole number in JavaScript?
... 5 5
~~value // 5 5 5
value | 0 // 5 5 5
value >> 0 // 5 5 5
value >>> 0 // 5 5 5
value - value % 1 // 5 5 5
Negative
// val...
What do the different readystates in XMLHttpRequest mean, and how can I use them?
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The full list of readyState values is:
State Description
0 The request is not initialized
1 The request has been set up
2 The request has been sent
3 The request is in process
4 The request is complete
(from https://www.w3schools.com/js/js_ajax_http_respo...
Cluster analysis in R: determine the optimal number of clusters
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1024
If your question is how can I determine how many clusters are appropriate for a kmeans analysi...
Why does one hot encoding improve machine learning performance?
...h" and "US". Assume, without loss of generality, that these are encoded as 0, 1 and 2. You then have a weight w for this feature in a linear classifier, which will make some kind of decision based on the constraint w×x + b > 0, or equivalently w×x < b.
The problem now is that the weight w c...
Gradients on UIView and UILabels On iPhone [duplicate]
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answered Jan 8 '09 at 0:59
Kendall Helmstetter GelnerKendall Helmstetter Gelner
72.5k2626 gold badges123123 silver badges146146 bronze badges
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How to print a percentage value in python?
...supports a percentage floating point precision type:
>>> print "{0:.0%}".format(1./3)
33%
If you don't want integer division, you can import Python3's division from __future__:
>>> from __future__ import division
>>> 1 / 3
0.3333333333333333
# The above 33% example wo...