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Count number of records returned by group by
...rGroup,
COUNT(*) OVER () AS TotalRecords
from temptable
group by column_1, column_2, column_3, column_4
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Why prefer two's complement over sign-and-magnitude for signed numbers?
...icle on two's complement for the full answer: en.wikipedia.org/wiki/Two%27s_complement. The short answer is the MSB 1 indicates -8, and the remaining three 1s indicate 4, 2, and 1, respectively, so -8+4+2+1 = -1.
– Welbog
Aug 23 '16 at 13:33
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How does deriving work in Haskell?
... Haskell Wiki:
In this example we use the following Haskell code
$(gen_render ''Body)
to produce the following instance:
instance TH_Render Body where
render (NormalB exp) = build 'normalB exp
render (GuardedB guards) = build 'guardedB guards
The function gen_render above is d...
Reference — What does this symbol mean in PHP?
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_ Alias for gettext()
The underscore character '_' as in _() is an alias to the gettext() function.
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List all indexes on ElasticSearch server?
...ise list of all indices in your cluster, call
curl http://localhost:9200/_aliases
this will give you a list of indices and their aliases.
If you want it pretty-printed, add pretty=true:
curl http://localhost:9200/_aliases?pretty=true
The result will look something like this, if your indices ...
Instance attribute attribute_name defined outside __init__
.... We expect to find all the attributes an instance may have by reading its __init__ method.
You may still want to split initialization into other methods though. In such case, you can simply assign attributes to None (with a bit of documentation) in the __init__ then call the sub-initialization met...
How can I recover the return value of a function passed to multiprocessing.Process?
... For example like this:
import multiprocessing
def worker(procnum, return_dict):
'''worker function'''
print str(procnum) + ' represent!'
return_dict[procnum] = procnum
if __name__ == '__main__':
manager = multiprocessing.Manager()
return_dict = manager.dict()
jobs = []
...
Length of generator output [duplicate]
...
The easiest way is probably just sum(1 for _ in gen) where gen is your generator.
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What does $_ mean in PowerShell?
...ich is called $PSItem in Powershell 3 and newer.
1,2,3 | %{ write-host $_ }
or
1,2,3 | %{ write-host $PSItem }
For example in the above code the %{} block is called for every value in the array. The $_ or $PSItem variable will contain the current value.
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What are the advantages of using a schema-free database like MongoDB compared to a relational databa
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– Sasha Chedygov
Mar 23 '13 at 20:06
Thanks @SashaChedygov. I agree with you. That was quite sloppy of the me of 201...