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How many database indexes is too many?
...that occur on the table.
If there's lots of SELECTs and very few changes, index all you like.... these will (potentially) speed the SELECT statements up.
If the table is heavily hit by UPDATEs, INSERTs + DELETEs ... these will be very slow with lots of indexes since they all need to be modified ea...
How do I read all classes from a Java package in the classpath?
... description from the above website:
Reflections scans your classpath, indexes the metadata, allows you to
query it on runtime and may save and collect that information for many
modules within your project.
Example:
Reflections reflections = new Reflections(
new ConfigurationBuilder()...
How much faster is C++ than C#?
... new List<double>(ROWS*COLS)' which allocates the memory required to index a 2 dimensional array in 1 dimensional format (eg, what you did in C++). There's absolutely no reason to allocate a 2-dimensional array and manually flatten it -- the massive amount of iterations in your pre-test is th...
How to use redis PUBLISH/SUBSCRIBE with nodejs to notify clients when data values change?
...unction() {
subscribe.quit();
});
});
}
./public/index.html
<html>
<head>
<title>PubSub</title>
<script src="/socket.io/socket.io.js"></script>
<script src="/javascripts/jquery-1.4.3.min.js"></script>
</head>...
Using Auto Layout in UITableView for dynamic cell layouts & variable row heights
...ased on the table view's width, minus any additional things like a section index or accessory view) and the auto layout constraints you have added to the cell's content view and subviews. Once this actual cell height has been determined, the old estimated height for the row is updated with the new a...
Make first letter of a string upper case (with maximum performance)
...t.First().ToString().ToUpper() + input.Substring(1);
}
}
}
Really old answers
public static string FirstCharToUpper(string input)
{
if (String.IsNullOrEmpty(input))
throw new ArgumentException("ARGH!");
return input.First().ToString().ToUpper() + String.Join("", input....
When to add what indexes in a table in Rails
...
Should I add "index" to all the foreign keys like "xxx_id"?
It would be better, because it accelerates the search in sorting in this column. And Foreign keys are something searched for a lot.
Since Version 5 of rails the index will be c...
Why would I want stage before committing in Git?
...
When you commit it's only going to commit the changes in the index (the "staged" files). There are many uses for this, but the most obvious is to break up your working changes into smaller, self-contained pieces. Perhaps you fixed a bug while you were implementing a feature. You can...
Lodash - difference between .extend() / .assign() and .merge()
...Mistic pointed out, Lodash treats arrays as objects where the keys are the index into the array.
_.assign ([], ['a'], ['bb']) // => [ "bb" ]
_.merge ([], ['a'], ['bb']) // => [ "bb" ]
_.defaults ([], ['a'], ['bb']) // => [ "a" ]
_.defaultsDeep([], ['a'], ['bb']) // => [ "...
What is the combinatory logic equivalent of intuitionistic type theory?
...!"
data Su a = Ze | Su a deriving (Show, Functor, Eq)
I use a de Bruijn index representation in the Bellegarde and Hook manner (as popularised by Bird and Paterson). The type Su a has one more element than a, and we use it as the type of free variables under a binder, with Ze as the newly bound v...