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What's the fastest way to merge/join data.frames in R?
..." case depending on the relative sizes of the tables, multiplicity of keys etc. (that's why I said I'm not sure if my example is representative). Nonetheless, it's nice to see all the different solutions to the problem.
– datasmurf
Dec 1 '10 at 23:27
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How can I display an image from a file in Jupyter Notebook?
...y? (Don't tell me that otherwise it doesn't work. Please explain why this call to 'display' is needed in a loop but not if you just dispaly one image).
– Kris
May 1 '17 at 1:25
12
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When increasing the size of VARCHAR column on a large table could there be any problems?
...har(max) is not. Because varchar(max) values (aka BLOB values - image/text etc) are stored differently on the disk, not within a table row, but "out of row". So the server will go nuts on a big table and become unresponsive for minutes (hours).
--no downtime
ALTER TABLE MyTable ALTER COLUMN [MyColu...
How can I list (ls) the 5 last modified files in a directory?
... format
-h makes output human readable (i.e. file sizes appear in kb, mb, etc.)
-t sorts output by placing most recently modified file first
head -6 will show 5 files because ls prints the block size in the first line of output.
I think this is a slightly more elegant and possibly more useful ap...
How do I implement an Objective-C singleton that is compatible with ARC?
...n;
dispatch_once(&onceToken, ^{
sharedInstance = [[MyClass alloc] init];
// Do any other initialisation stuff here
});
return sharedInstance;
}
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What do parentheses surrounding an object/function/class declaration mean? [duplicate]
... useful construct when trying to hide variables from the parent namespace. All the code within the function is contained in the private scope of the function, meaning it can't be accessed at all from outside the function, making it truly private.
See:
http://en.wikipedia.org/wiki/Closure_%28comput...
How to check SQL Server version
...ineEdition) properties to determine RTM / SPn / CTPn and Dev / Std / Ent / etc respectively.
SELECT
CAST(SERVERPROPERTY('ProductVersion') AS SYSNAME) AS ProductVersion,
CAST(SERVERPROPERTY('ProductLevel') AS SYSNAME) AS ProductLevel,
CAST(SERVERPROPERTY('Edition') AS SYSNAME) A...
How do you copy and paste into Git Bash
...Edit -> Paste which is exactly what I want! No more typing API code manually!
– Trav L
Feb 21 '10 at 1:08
27
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What is the difference between indexOf() and search()?
...you to match against more sophisticated patters, case-insensitive strings, etc., while indexOf (one description here) simply matches a literal string. However, indexOf also allows you to specify a beginning index.
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How to create new tmux session if none exists
...ause with a small tweak this works with named sessions: tmux attach -t some_name || tmux new -s some_name. Change some_name to $1 add a shebang, and save.
– Cheezmeister
Jan 9 '14 at 4:48
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