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Understanding exactly when a data.table is a reference to (vs a copy of) another data.table
...00000000040ED948]:
# tracemem[00000000040ED948 -> 00000000040ED830]: .Call copy $<-.data.table $<-
.Internal(inspect(DT))
# @0000000003B7E2A0 19 VECSXP g0c7 [OBJ,NAM(2),TR,ATT] (len=2, tl=100)
# @00000000040C2288 14 REALSXP g0c2 [NAM(2)] (len=2, tl=0) 1,2
# @00000000040C2250 14 REALS...
How can I push to my fork from a clone of the original repo?
I created a fork (let's call it myrepo ) of another repository (let's call it orirepo ) on GitHub. Later, I cloned orirepo .
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What's faster, SELECT DISTINCT or GROUP BY in MySQL?
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They are essentially equivalent to each other (in fact this is how some databases implement DISTINCT under the hood).
If one of them is faster, it's going to be DISTINCT. This is because, although the two are the same, a query optimizer wo...
Why is “Set as Startup” option stored in the suo file and not the sln file?
...e this setting should be stored in the solution file so it's shared across all users and part of source code control. Since we don't check in the suo file, each user has to set this separately which seems strange.
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How to use ArgumentCaptor for stubbing?
...n is a different story. If your test needs to ensure that this method was called with a specific argument, use ArgumentCaptor and this is the case for which it is designed:
ArgumentCaptor<SomeClass> argumentCaptor = ArgumentCaptor.forClass(SomeClass.class);
verify(someObject).doSomething(argu...
How to delete object from array inside foreach loop?
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@Oliver: usually it will generate unexpected behavior, but you can do it safely with foreach on php. Give a read here for a test: php.net/manual/en/control-structures.foreach.php#88578
– pangon
Jan ...
Why is LINQ JOIN so much faster than linking with WHERE?
...ite efficient because the DB knows how to perform a join. But it doesn't really make sense to compare it with the other approaches, since they work directly in memory (Linq to DataSet)
The query with multiple tables and a Where condition actually performs a cartesian product of all the tables, then ...
What C++ Smart Pointer Implementations are available?
...g limited garbage collection facilities. The first downside being that it calls delete upon destruction making them unacceptable for holding array allocated objects (new[]). It takes ownership of the pointer so two auto pointers shouldn't contain the same object. Assignment will transfer ownership a...
How to configure 'git log' to show 'commit date'
... make it the commit date, you can use git log --format=<some stuff>. All the allowable codes for defining the format are documented in git help log. The commit date is one of %cd, %cD, %cr, %ct or %ci, depending on what format you prefer it in.
If it's something you want to do often, put it i...
How can I git stash a specific file?
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Not the most user-friendly approach, but it gets the work done if you really need it.
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