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Which SQL query is faster? Filter on Join criteria or Where clause?
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Performance-wise, they are the same (and produce the same plans)
Logically, you should make the operation that still has sense if you replace INNER JOIN with a LEFT JOIN.
In your very case this will look like this:
SELECT *
FROM TableA a
LEFT JOIN
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How to git-svn clone the last n revisions from a Subversion repository?
... graph (DAG), which makes it trivial to walk back n commits. But in SVN ( and therefore in Git-SVN) you will have to find the revision number yourself.
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How to check if a process id (PID) exists
...will have a race condition.
If you want to ignore the text output of kill and do something based on the exit code, you can
if ! kill $pid > /dev/null 2>&1; then
echo "Could not send SIGTERM to process $pid" >&2
fi
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How do I parse XML in Python?
I have many rows in a database that contains XML and I'm trying to write a Python script to count instances of a particular node attribute.
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How to write a cron that will run a script every day at midnight?
I have heard crontab is a good choice, but how do I write the line and where do I put it on the server?
6 Answers
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How to add property to a class dynamically?
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I suppose I should expand this answer, now that I'm older and wiser and know what's going on. Better late than never.
You can add a property to a class dynamically. But that's the catch: you have to add it to the class.
>>> class Foo(...
Getting value of select (dropdown) before change
...he value of the dropdown before change. I am using 1.3.2 version of jQuery and using on change event but the value I am getting over there is after change.
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How to convert enum value to int?
... tax.getValue();
}
(I've changed the names to be a bit more conventional and readable, btw.)
This is assuming you want the value assigned in the constructor. If that's not what you want, you'll need to give us more information.
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Does the C++ standard mandate poor performance for iostreams, or am I just dealing with a poor imple
Every time I mention slow performance of C++ standard library iostreams, I get met with a wave of disbelief. Yet I have profiler results showing large amounts of time spent in iostream library code (full compiler optimizations), and switching from iostreams to OS-specific I/O APIs and custom buffer...
Python Sets vs Lists
...cture is more efficient/speedy? Assuming that order is not important to me and I would be checking for duplicates anyway, is a Python set slower than a Python list?
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