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Multiple INSERT statements vs. single INSERT with multiple VALUES
I'm running a performance comparison between using 1000 INSERT statements:
4 Answers
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How to make an element in XML schema optional?
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Try this
<xs:element name="description" type="xs:string" minOccurs="0" maxOccurs="1" />
if you want 0 or 1 "description" elements, Or
<xs:element name="description" type="xs:string" minOccurs="0" maxOccurs="unbounded" />
if you want 0 to infinity number of "description" elements...
promise already under evaluation: recursive default argument reference or earlier problems?
...g the two instances where they occur we get:
f <- function(x, T) {
10 * sin(0.3 * x) * sin(1.3 * x^2) + 0.001 * x^3 + 0.2 * x + 80
}
g <- function(x, T, f. = f) { ## 1. note f.
exp(-f.(x)/T)
}
test<- function(g. = g, T = 1) { ## 2. note g.
g.(1,T)
}
test()
## [1] 8.560335e...
Keep only first n characters in a string?
...r JavaScript's String method substring
e.g.
'Hiya how are you'.substring(0,8);
Which returns the string starting at the first character and finishing before the 9th character - i.e. 'Hiya how'.
substring documentation
s...
Center image horizontally within a div
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edited Jan 20 '18 at 23:10
TylerH
18.1k1212 gold badges6161 silver badges8080 bronze badges
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What is a bank conflict? (Doing Cuda/OpenCL programming)
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105
For nvidia (and amd for that matter) gpus the local memory is divided into memorybanks. Each ba...
How can I make setuptools install a package that's not on PyPI?
...g it to http://github.com/mtai/python-gearman/tarball/master#egg=gearman-2.0.0beta instead, easy_install will be able to identify the package name and its version.
The final step is to add the URL to your package's dependency_links, e.g.:
setup(
...
dependency_links = ['http://github.com/mta...
How to sort a dataFrame in python pandas by two or more columns?
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490
As of the 0.17.0 release, the sort method was deprecated in favor of sort_values. sort was comp...
Is there a difference between x++ and ++x in java?
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answered Jul 7 '09 at 21:09
Emil HEmil H
37.1k1010 gold badges7171 silver badges9494 bronze badges
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Adding 'serial' to existing column in Postgres
I have a small table (~30 rows) in my Postgres 9.0 database with an integer ID field (the primary key) which currently contains unique sequential integers starting at 1, but which was not created using the 'serial' keyword.
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