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Linux error while loading shared libraries: cannot open shared object file: No such file or director
...ies found in the directories specified on the command
line, in the file /etc/ld.so.conf, and in the trusted directories
(/lib and /usr/lib).
Usually your package manager will take care of this when you install a new library, but not always, and it won't hurt to run ldconfig even if that is not...
What is SELF JOIN and when would you use it? [duplicate]
...yee as boss
from emptable e, emptable b
where e.manager_id = b.empolyee_id
order by 1
It's basically used where there is any relationship between rows stored in the same table.
employees.
multi-level marketing.
machine parts.
And so on...
...
Why were pandas merges in python faster than data.table merges in R in 2012?
....table has time series merge in mind. Two aspects to that: i) multi column ordered keys such as (id,datetime) ii) fast prevailing join (roll=TRUE) a.k.a. last observation carried forward.
I'll need some time to confirm as it's the first I've seen of the comparison to data.table as presented.
UPD...
How to retrieve an element from a set without removing it?
... since iteration seems to sort the elements. I would prefer them in random order...
– Daren Thomas
Sep 12 '08 at 20:17
10
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What is the difference between “#!/usr/bin/env bash” and “#!/usr/bin/bash”?
...$PATH). If you now call bash, the shell will first look for it in $PATH in order, so it starts with ~/bin, where it will find your bash. Same thing happens if scripts search for bash using #!/usr/bin/env bash, so these scripts would now be working on your system using your custom bash build.
One do...
Laravel - Eloquent or Fluent random row
...
Laravel >= 5.2:
User::inRandomOrder()->get();
or to get the specific number of records
// 5 indicates the number of records
User::inRandomOrder()->limit(5)->get();
// get one random record
User::inRandomOrder()->first();
or using the random ...
Vertically align an image inside a div with responsive height
...ation to the first-child and our element (the image) both.
3) Finally, in order to remove the white space character between inline(-block) elements, we could set the font size of the parent to zero by font-size: 0;.
Note: I used Nicolas Gallagher's image replacement technique in the following.
Wh...
Node.js: what is ENOSPC error and how to solve?
...d to avoid ENOSPC:
echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
For Arch Linux add this line to /etc/sysctl.d/99-sysctl.conf:
fs.inotify.max_user_watches=524288
Then execute:
sysctl --system
This will also persist across reboots.
Technic...
What is the difference between “INNER JOIN” and “OUTER JOIN”?
...great and excellent explanation. but why in column b the values are not in order? i.e it is 6,5 not as 5,6?
– Ameer
Mar 4 '13 at 8:39
...
Where can I learn how to write C code to speed up slow R functions? [closed]
...simpler code, less boilerplate, no PROTECT/UNPROTECT, no memory management etc pp. Doug Bates just yesterday stated that he finds C++ and Rcpp to be much more like writing R than writing C++. YMMV and all that.
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