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SQL WHERE condition is not equal to?
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BrandonBrandon
64.2k2929 gold badges186186 silver badges218218 bronze badges
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How expensive is RTTI?
...runtime memory usage.
A quick experiment (using GCC 4.4.3 on Ubuntu 10.04 64-bit) shows that -fno-rtti actually increases the binary size of a simple test program by a few hundred bytes. This happens consistently across combinations of -g and -O3. I'm not sure why the size would increase; one possi...
mysql: see all open connections to a given database?
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64
As well you can use:
mysql> show status like '%onn%';
+--------------------------+-------+
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What optimizations can GHC be expected to perform reliably?
...ckage integer-gmp mapped to integer-gmp-0.4.0.0-af3a28fdc4138858e0c7c5ecc2a64f43
wired-in package base mapped to base-4.5.1.0-6e4c9bdc36eeb9121f27ccbbcb62e3f3
wired-in package rts mapped to builtin_rts
wired-in package template-haskell mapped to template-haskell-2.7.0.0-2bd128e15c2d50997ec26a1eaf8b2...
Is mongodb running?
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hmm, works for me (Ubuntu 64bit VM, Mongo v1.7.6), so I'm not sure why it's not for you tbh. If you can't get it working, best bet may be to post it on the mongodb forums: groups.google.com/group/mongodb-user
– AdaTheDev
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Hiding the scroll bar on an HTML page
...: auto, but I'm not a fan of abusing width for visibility tweaks.
Firefox 64 now supports the experimental scrollbar-width property by default (63 requires a configuration flag to be set). To hide the scrollbar in Firefox 64:
#element {
scrollbar-width: none;
}
To see if your current browser...
count the frequency that a value occurs in a dataframe column
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In [38]:
df['a'].value_counts()
Out[38]:
b 3
a 2
s 2
dtype: int64
If you wanted to add frequency back to the original dataframe use transform to return an aligned index:
In [41]:
df['freq'] = df.groupby('a')['a'].transform('count')
df
Out[41]:
a freq
0 a 2
1 b 3
2 s 2...
Update just one gem with bundler
...undle update
> ruby -v
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-darwin19]
> gem -v
3.0.3
> bundle -v
Bundler version 2.1.4
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离线版启动超时，有报错日志 - App Inventor 2 离线版 - 清泛IT社区，为创新赋能！
...ed\tmp" -Dfile.encoding=UTF-8
Picked up _JAVA_OPTIONS: -Xms64m -Xmx4G
Exception in thread "main" java.lang.NoClassDefFoundError: javax/ws/rs/core/Configurable
at java.base/java.lang.ClassLoader.defineClass1(Native Method)
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Lua string to int
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In Lua 5.3, (64-bit default) integers are treated accordingly (lua.org/manual/5.3/manual.html): "A numeric constant with a fractional dot or an exponent denotes a float; otherwise it denotes an integer."
– Kevin Lee
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