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postgresql COUNT(DISTINCT …) very slow
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I found this thread on www.postgresql.org which discusses the same thing: link. One of the replies (by Jeff Janes) says that COUNT(DISTINCT()) sorts the table to do its work instead of using hash.
– Ankur
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Why is reading lines from stdin much slower in C++ than Python?
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einpoklum
76.5k3535 gold badges190190 silver badges393393 bronze badges
answered Feb 21 '12 at 3:24
Vaughn CatoVaughn Cato
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XAMPP - MySQL shutdown unexpectedly
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Should programmers use SSIS, and if so, why? [closed]
... a lot of script then your team is using SSIS for the wrong tasks or isn't comfortable with SQL or has bought into the hype. SSIS packages are very difficult to debug. Script components are an absolute nightmare and should be used only for formatting, looping, or as a last resort.
Keep your packag...
How do function pointers in C work?
...b\x5c\x24\x08\x8b\x00\x8b\x1b\x31\xc3\x31\xd8\x31\xc3\x8b\x4c\x24\x04\x89\x01\x8b\x4c\x24\x08\x89\x19\xc3 <- This swaps the values of a and b")(&a,&b);
Write a for-loop counter to 1000, calling some function each time
((int(*)())"\x66\x31\xc0\x8b\x5c\x24\x04\x66\x40\x50\xff\xd3\x58\x66\...
How do I pre-populate a jQuery Datepicker textbox with today's date?
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In Ruby on Rails, how do I format a date with the “th” suffix, as in, “Sun Oct 5th”?
...e method from 'active_support'.
>> time = Time.new
=> Fri Oct 03 01:24:48 +0100 2008
>> time.strftime("%a %b #{time.day.ordinalize}")
=> "Fri Oct 3rd"
Note, if you are using IRB with Ruby 2.0, you must first run:
require 'active_support/core_ext/integer/inflections'
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How to get a random number in Ruby
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answered May 5 '10 at 14:01
Marc-André LafortuneMarc-André Lafortune
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Keep file in a Git repo, but don't track changes
... First change the file you do not want to be tracked and use the following command:
git update-index --assume-unchanged FILE_NAME
and if you want to track the changes again use this command:
git update-index --no-assume-unchanged FILE_NAME
git-update-index documentation
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How to find the last day of the month from date?
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