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Django migration strategy for renaming a model and relationship fields
...igration(migrations.Migration):
dependencies = [
('myapp', '00XX_the_migration_of_myapp_with_renamemodel_foo_bar'),
('myotherapp', '00xx_the_migration_of_myotherapp_with_integerfield'),
]
operations = [
migrations.AlterField(
model_name='anothermodel...
How to set the maximum memory usage for JVM?
...
Pretty sure you can control it via -XX:MaxDirectMemorySize. Not that I've profiled heavily to make sure but still ;)
– alexandergunnarson
Feb 2 '17 at 16:37
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How would I get a cron job to run every 30 minutes?
...
@Adam Hawes: I've also used */xx with success in the past, but on Linux and other UNIXes. I've not personally tried Mac OSX. The original question didn't say which OS. Some older UNIXes don't support */xx
– Eddie
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What is the difference among col-lg-*, col-md-* and col-sm-* in Bootstrap?
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Updated 2020...
Bootstrap 5
In Bootstrap 5 (alpha) there is a new -xxl- size:
col-* - 0 (xs)
col-sm-* - 576px
col-md-* - 768px
col-lg-* - 992px
col-xl-* - 1200px
col-xxl-* - 1400px
Bootstrap 5 Grid Demo
Bootstrap 4
In Bootstrap 4 there is a new -xl- size, see this demo. Also the -xs- infix ...
Getting and removing the first character of a string
... character vector of length > 1.
# a slightly more interesting example
xx <- c('hello stackoverflow', 'right back', 'at yah')
# grab the substrings
myStrings <- regmatches(x, regexec('(^.)(.*)', xx))
This returns a list with the matched full string as the first element and the matching ...
How do I “source” something in my .vimrc file?
...Stuff.vim
:so myStuff.vim
and if myStuff.vim contained these lines
set xx iI just intersted this<C-]>
set yy bbbb4dw
It's the same as if you typed those commands into Vim
:set xx iI just intersted this<C-]>
:set yy bbbb4dw
The only file sourced by default is the .vimrc(_vimrc on...
Postgres dump of only parts of tables for a dev snapshot
...strained data into a "template" database and used CREATE DATABASE test_run_XX TEMPLATE product_snapshot_XX. I of course widdled the data down to a bare minimum so the product snapshot loaded and test db creation operations are fast enough to not be a team impediment.
– Trey
...
Maximum Java heap size of a 32-bit JVM on a 64-bit OS
...faq-138619.html#gc_heap_32bit).
We ran our app with -Xms2560m -Xmx2560m -XX:MaxPermSize=512m -XX:PermSize=512m with no issues on Solaris for past couple of years. Tried to move it to linux and we had issues with random out of memory errors on start up. We could only get it to consistently start up...
error: Unable to find vcvarsall.bat
...it compiler tools:
Setting environment for using Microsoft Visual Studio 20xx x86 tools.
For the 64-bit compiler tools:
Setting environment for using Microsoft Visual Studio 20xx x64 tools.
Now, run the setup via python setup.py install or pip install pkg-name
Hope and cross your fingers that the...
由12306.cn谈谈网站性能技术 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...程，并发的控制也相对麻烦一些。d）很多异步系统都用消息机制，消息的丢失和乱序也会是比较复杂的问题。
throttle 技术其实并不提升性能，这个技术主要是防止系统被超过自己不能处理的流量给搞垮了，这其实是个保护...