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Best practices for SQL varchar column length [closed]
...t into it, not the max length you define. So from a storage point of view (and most probably a performance one as well), it does not make any difference whether you declare a column as VARCHAR(100) or VARCHAR(500).
You should see the max length provided for a VARCHAR column as a kind of constraint...
What is a Y-combinator? [closed]
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@Andre MacFie: I didn't comment on the effort, I commented on the quality. In general, the policy on Stack Overflow is that answers should be self contained, with links to more information.
– Jørgen Fogh...
EC2 Can't resize volume after increasing size
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Thank you Wilman your commands worked correctly, small improvement need to be considered if we are increasing EBSs into larger sizes
Stop the instance
Create a snapshot from the volume
Create a new volume based on the snapshot increasing the size
Ch...
What's the difference between SoftReference and WeakReference in Java?
What's the difference between java.lang.ref.WeakReference and java.lang.ref.SoftReference ?
12 Answers
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What is the most efficient/elegant way to parse a flat table into a tree?
..., we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursive que...
What is the difference between NaN and None?
I am reading two columns of a csv file using pandas readcsv() and then assigning the values to a dictionary. The columns contain strings of numbers and letters. Occasionally there are cases where a cell is empty. In my opinion, the value read to that dictionary entry should be None but instead ...
UIView frame, bounds and center
...to add more correct content.
First a recap on the question: frame, bounds and center and theirs relationships.
Frame A view's frame (CGRect) is the position of its rectangle in the superview's coordinate system. By default it starts at the top left.
Bounds A view's bounds (CGRect) expresses a vie...
How to decide font color in white or black depending on background color?
...need to break the hex code into 3 pieces to get the individual red, green, and blue intensities. Each 2 digits of the code represent a value in hexadecimal (base-16) notation. I won't get into the details of the conversion here, they're easy to look up.
Once you have the intensities for the individ...
“R cannot be resolved to a variable”? [duplicate]
In Eclipse, I've created a project from a source and now it shows errors - "R cannot be resolved to a variable". From what I found here, I had cleared and rebuilt the project, but still the R file doesn't appear in the /gen folder.
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How can I print variable and string on same line in Python?
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Use , to separate strings and variables while printing:
print "If there was a birth every 7 seconds, there would be: ",births,"births"
, in print statement separates the items by a single space:
>>> print "foo","bar","spam"
foo bar spam
or ...