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Favourite performance tuning tricks [closed]
...Nice Joins
By default the optimiser will only consider the tables 4 at a time.
This means that in joins with more than 4 tables, it has a good chance of choosing a non-optimal query plan
Break up the Join
Can you break up the join?
Pre-select foreign keys into a temporary table
Do half the ...
Using C# to check if string contains a string in string array
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How has this answer been upvoted so many times? 5 years after the question is asked and the solution is basically reversed of what the question is asking.
– Fus Ro Dah
Mar 27 '18 at 21:46
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Django: multiple models in one template using forms [closed]
...he better options around. If you don't get too fancy with it it saves some time. I can imagine when you want to start customizing and doing non-trivial forms it would be easier to roll your own. Easily mixing forms and contexts in views is the first feature I really think I missed in django.
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How to create streams from string in Node.Js?
...unction was added in 10.7, and behaved the way I originally described. Sometime since, strings no longer need to be wrapped in arrays (since 12.3, it no longer iterates each character individually).
– Fizker
May 17 at 21:32
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Git Push into Production (FTP)
... to a FTP server,
which have changed since the last
upload. This saves time and bandwith.
Even if you play with different
branches, git-ftp.sh knows which files
are different. No ordinary FTP client
can do that.
git-ftp by Edward Z. Yang is a
simple script written in python for
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The JPA hashCode() / equals() dilemma
... It is a great article. However, for people who see the link for the first time, I would suggest that it might be an overkill for most applications. The other 3 options listed on this page should more or less solve the issue in multiple ways.
– HopeKing
Jul 1 '...
Casting vs using the 'as' keyword in the CLR
... is followed by a cast.
I don't think any of the answers so far (at the time of starting this answer!) have really explained where it's worth using which.
Don't do this:
// Bad code - checks type twice for no reason
if (randomObject is TargetType)
{
TargetType foo = (TargetType) randomObje...
How to best position Swing GUIs?
...owing system or at the current location (returned by getLocation) the next time the Window is made visible. This behavior resembles a native window shown without programmatically setting its location. Most windowing systems cascade windows if their locations are not explicitly set. The actual locati...
Random date in C#
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private Random gen = new Random();
DateTime RandomDay()
{
DateTime start = new DateTime(1995, 1, 1);
int range = (DateTime.Today - start).Days;
return start.AddDays(gen.Next(range));
}
For better performance if this will be called repeated...
NOT IN vs NOT EXISTS
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execution planner time may be same but execution results can differ so there is a difference. NOT IN will produce unexpected results if you have NULL in your dataset (see buckley's answer). Best to use NOT EXISTS as a default.
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