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What is PostgreSQL explain telling me exactly?
...content: "• EXPLAIN works on any DML not just SELECT (ie UPDATE, DELETE, and INSERT)". My biggest misunderstanding is what "startup" time means, and that's not explained anywhere in these ~30 slides.
– Mark E. Haase
Feb 19 '16 at 15:51
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Bash script processing limited number of commands in parallel
...ple, 4 processes process1 ... process4 would be started in the background, and the shell would wait until those are completed before starting the next set.
From the GNU manual:
wait [jobspec or pid ...]
Wait until the child process specified by each process ID pid or job specification jobsp...
error: writable atomic property cannot pair a synthesized setter/getter with a user defined setter/g
...tried to compile an older Xcode project (which used to compile just fine), and now I'm seeing a lot of errors of this form:
...
How to list commits since certain commit?
... a commit that's just one back (one leg of a merge). What is it telling me and how is that useful?
– ErikE
Feb 26 '17 at 1:30
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“tag already exists in the remote" error after recreating the git tag
...o get everyone who already has the "wrong" tag to delete their "wrong tag" and replace it with the new "right tag".
Testing in Git 2.10/2.11 shows that retaining the old tag is the default behavior for clients running git fetch, and updating is the default behavior for clients running git fetch --t...
git - Find commit where file was added
...it-log#Documentation/git-log.txt---diff-filterACDMRTUXB82308203
I have a handy alias for this, because I always forget it:
git config --global alias.whatadded 'log --diff-filter=A'
This makes it as simple as:
git whatadded -- foo.js
The below one liner will recursively search through sub di...
No secret option provided to Rack::Session::Cookie warning?
....2.3, Ruby 1.9 under Fedora 17. I get this warning, when I run rails s , and how do I fix?
7 Answers
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Android image caching
...
And now the punchline: use the system cache.
URL url = new URL(strUrl);
URLConnection connection = url.openConnection();
connection.setUseCaches(true);
Object response = connection.getContent();
if (response instanceof Bitma...
Perform Segue programmatically and pass parameters to the destination view
...ue is triggered.
The prepareForSegue:sender: method is called in any case and this is where you pass your parameters across.
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Rails :dependent => :destroy VS :dependent => :delete_all
...s with the callback.
The :delete_all is made directly in your application and deletes by SQL :
DELETE * FROM users where compagny_id = XXXX
With the :destroy, there is an instantiation of all of your children. So, if you can't destroy it or if each has their own :dependent, its callbacks can be ...