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SQL - many-to-many table primary key
...to be able to be retrieved quickly.
In addition, the vast majority of database tables are read far more often than written. That makes anything you do on the select side far more relevant than anything on the insert side.
s...
Does the join order matter in SQL?
...OIN. Does it work like that first the query will Filter the records on the base of INNER JOIN and then will apply LEFT JOIN to the Filtered records?
– Muhammad Babar
Feb 12 '15 at 13:09
...
Mongodb Explain for Aggregation framework
...ious types of reports or analysis on documents in one or more collections. Based on the idea of a pipeline. We take input from a MongoDB collection and pass the documents from that collection through one or more stages, each of which performs a different operation on it's inputs. Each stage takes as...
Why would I ever use push_back instead of emplace_back?
...d construct it directly in place with no copies or moves. This may be true based on the code as written in standard libraries, but it makes the mistaken assumption that the optimizing compiler's job is to generate the code you wrote. The optimizing compiler's job is actually to generate the code you...
Why is NaN not equal to NaN? [duplicate]
... people wanted to use NaN to represent missing values and put them in hash-based containers, they couldn't do it.
If the committee foresaw future use cases, and considered them important enough, they could have gone for the more verbose !(x<x & x>x) instead of x!=x as a test for NaN. How...
Do HttpClient and HttpClientHandler have to be disposed between requests?
...nges. This can be an issue in scenarios like blue/green deployment and DNS-based failover. There are various approaches for dealing with this issue, the most reliable one involving the server sending out a Connection:close header after DNS changes take place. Another possibility involves recycling t...
Shell equality operators (=, ==, -eq)
...-eq causes the strings to be interpreted as integers if possible including base conversion:
$ [[ "0x10" -eq 16 ]]; echo $?
0
$ [[ "010" -eq 8 ]]; echo $?
0
$ [[ "100" -eq 100 ]]; echo $?
0
And 0 if Bash thinks it is just a string:
$ [[ "yes" -eq 0 ]]; echo $?
0
$ [[ "yes" -eq 1 ]]; echo $?
1
S...
What are the mechanics of short string optimization in libc++?
...ng
Note: __compressed_pair is essentially a pair optimized for the Empty Base Optimization, aka template <T1, T2> struct __compressed_pair: T1, T2 {};; for all intents and purposes you can consider it a regular pair. Its importance just comes up because std::allocator is stateless and thus e...
Implementing MVC with Windows Forms
... I have seen are (including most combinations):
Directly talk to the database (2 tier)
Use a backend that has been written for the given application (3 tier)
Use a set of web services that were written for use by many applications and can’t be changed for your application. (Service-oriented arch...
node.js child process - difference between spawn & fork
...n essentially create multiple workers, running on the exact same Node code base, or perhaps a different module for a specific task. This is most useful for creating a worker pool. While node's async event model allows a single core of a machine to be used fairly efficiently, it doesn't allow a nod...