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Grouped LIMIT in PostgreSQL: show the first N rows for each group?
I need to take the first N rows for each group, ordered by custom column.
5 Answers
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How do you remove duplicates from a list whilst preserving order?
... a built-in that removes duplicates from list in Python, whilst preserving order? I know that I can use a set to remove duplicates, but that destroys the original order. I also know that I can roll my own like this:
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Why is my variable unaltered after I modify it inside of a function? - Asynchronous code reference
...llback passing the result. The implementation (please read the comments in order):
// 1. Call helloCatAsync passing a callback function,
// which will be called receiving the result from the async operation
helloCatAsync(function(result) {
// 5. Received the result from the async function,
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capturing self strongly in this block is likely to lead to a retain cycle
...etter read from right to left. Declaring SomeType* __weak variable in this order reads more naturally from right to left as: variable is a weak pointer to SomeType.
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Why can tuples contain mutable items?
...ings down, and would certainly be less memory efficient.
So you see, in order to fulfill their purpose, tuples must be immutable, but also must be able to contain mutable objects. If the designers of Python wanted to create an immutable object that guarantees that all the objects it "contains" ar...
Rspec: “array.should == another_array” but without concern for order
...o compare arrays and make sure that they contain the same elements, in any order. Is there a concise way to do this in RSpec?
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What are the differences between git branch, fork, fetch, merge, rebase and clone?
... there needs to be a way to 'know' about those branches and their names in order to be able to pull them down locally. This is done via a git fetch which will get all new and changed branches into the locally repository using the tracking branches (e.g., origin/). Once fetched, one can git branch ...
Chaining multiple MapReduce jobs in Hadoop
...ntifying dependent things and 'executing' them in dependency (topological) order.
Or you can use a Cascade (and MapReduceFlow) in Cascading ( http://www.cascading.org/ ). A future version will support Riffle annotations, but it works great now with raw MR JobConf jobs.
A variant on this is to not ...
URL rewriting with PHP
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What is the template binding vs binding?
I could not understand BorderThickness="{TemplateBinding BorderThickness} .
Here the code:
4 Answers
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