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What columns generally make good indexes?
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Indexes can play an important role in query optimization and searching the results speedily from tables. So it is most important step to select which columns to be indexed. There are two major places where we can consider indexing: columns referenced in the WHERE clause and colu...
Growing Amazon EBS Volume sizes [closed]
I'm quite impressed with Amazon's EC2 and EBS services. I wanted to know if it is possible to grow an EBS Volume.
11 Answer...
How to prevent SIGPIPEs (or handle them properly)
I have a small server program that accepts connections on a TCP or local UNIX socket, reads a simple command and, depending on the command, sends a reply. The problem is that the client may have no interest in the answer sometimes and exits early, so writing to that socket will cause a SIGPIPE and m...
puts vs logger in rails rake tasks
In a rake task if I use puts command then I see the output on console. However I will not see that message in log file when app is deployed on production.
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Can't find the 'libpq-fe.h header when trying to install pg gem
I am using the Ruby on Rails 3.1 pre version. I like to use PostgreSQL, but the problem is installing the pg gem. It gives me the following error:
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How Do I Choose Between a Hash Table and a Trie (Prefix Tree)?
...efix tree what are the discriminating factors that would lead me to choose one over the other. From my own naive point of view it seems as though using a trie has some extra overhead since it isn't stored as an array but that in terms of run time (assuming the longest key is the longest english word...
Database cluster and load balancing
What is database clustering? If you allow the same database to be on 2 different servers how do they keep the data between synchronized. And how does this differ from load balancing from a database server perspective?
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What is the difference between concurrency, parallelism and asynchronous methods?
Concurrency is having two tasks run in parallel on separate threads. However, asynchronous methods run in parallel but on the same 1 thread. How is this achieved? Also, what about parallelism?
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Left Join With Where Clause
...ttings`.`value`
FROM `settings`
LEFT JOIN
`character_settings`
ON `character_settings`.`setting_id` = `settings`.`id`
AND `character_settings`.`character_id` = '1'
share
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Is it possible to await an event instead of another async method?
In my C#/XAML metro app, there's a button which kicks off a long-running process. So, as recommended, I'm using async/await to make sure the UI thread doesn't get blocked:
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