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.NET - Dictionary locking vs. ConcurrentDictionary
...gging the clerk, this will anger the other customers in line behind you.
Now consider this. In the store with one clerk, what if you get all the way to the front of the line, and ask the clerk "Do you have any toilet paper", and he says "Yes", and then you go "Ok, I'll get back to you when I know ...
Java “lambda expressions not supported at this language level”
... to 1.8 from 1.7 or lower. Do not change anything else. -> Click Apply
now gradle will re-sync and your error will be removed.
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Inline labels in Matplotlib
... less than 0.2). See this question for a particularly nasty example. Right now, the code does not intelligently identify this scenario and re-arrange the labels, however there is a reasonable workaround. The labelLines function takes the xvals argument; a list of x-values specified by the user inste...
must appear in the GROUP BY clause or be used in an aggregate function
...erver just don't allow this at all. Mysql used to allow it by default, but now since 5.7 the administrator needs to enable this option (ONLY_FULL_GROUP_BY) manually in the server configuration for this feature to be supported...
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Ways to save Backbone.js model data?
...what Backbone uses internally but since it doesn't have an official ID it knows that it should create a new resource and it sends a POST request. If you got your model from the server, it will probably have an ID if all was right. In this case, when you save() Backbone assumes you want to update the...
How Do I Choose Between a Hash Table and a Trie (Prefix Tree)?
...suffixes as well, by hash-consing.
Advantages of hashtables:
Everyone knows hashtables, right? Your system will already have a nice well-optimized implementation, faster than tries for most purposes.
Your keys need not have any special structure.
More space-efficient than the obvious linked tri...
MySQL order by before group by
...publish', post_type='post', post_author='user A', post_date='2012-12-31')
Now, when you order the results of the grouping by post_date, you get the data you wanted.
SELECT wp_posts.*
FROM wp_posts
WHERE wp_posts.post_status='publish' AND wp_posts.post_type='post'
GROUP BY wp_posts.post_author DESC...
How do you find the row count for all your tables in Postgres
...looking for a way to find the row count for all my tables in Postgres. I know I can do this one table at a time with:
15 A...
What's the best way to check if a file exists in C?
... == EEXIST) {
/* the file already existed */
...
}
} else {
/* now you can use the file */
}
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How can I handle time zones in my webapp?
...down and default to the device timezone (because the user doesn't need to know about them). In either case, have a setting in the app that allows the user to manually show/hide the timezone dropdown.
To summarise the above:
On first run, save what timezone the device is set to.
Use that timezon...