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How to implement a many-to-many relationship in PostgreSQL?
...ct is hardly unique (not a good "natural key"). Also, enforcing uniqueness and referencing the column in foreign keys is typically cheaper with a 4-byte integer (or even an 8-byte bigint) than with a string stored as text or varchar.
Don't use names of basic data types like date as identifiers. Whi...
Regex lookahead for 'not followed by' in grep
...head, which is what you're after, requires a more powerful tool than the standard grep. You need a PCRE-enabled grep.
If you have GNU grep, the current version supports options -P or --perl-regexp and you can then use the regex you wanted.
If you don't have (a sufficiently recent version of) GNU ...
What is Normalisation (or Normalization)?
...Normalization is basically to design a database schema such that duplicate and redundant data is avoided. If some piece of data is duplicated several places in the database, there is the risk that it is updated in one place but not the other, leading to data corruption.
There is a number of normal...
Git pull without checkout?
I'm used to running git pull and other commands from within a branch I'm working on. But I have set up a development server that several people work on, so I don't want to have to switch branches when I do it. If I want to update an existing branch on the dev server from the github repository we a...
Running PostgreSQL in memory only
...y for this particular question: It's a bad idea to mix with valuable data (and thanks for the warning). For unit-testing with a dedicated DB cluster, a ramdisk is fine.
– Erwin Brandstetter
Jul 12 '15 at 0:32
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Track a new remote branch created on GitHub
... Now, a collaborator of mine has created a new branch in the same project, and I want to do the following accordingly:
4 An...
Reading file contents on the client-side in javascript in various browsers
...ince I originally wrote this answer, the File API has been proposed as a standard and implemented in most browsers (as of IE 10, which added support for FileReader API described here, though not yet the File API). The API is a bit more complicated than the older Mozilla API, as it is designed to sup...
sqlalchemy: how to join several tables by one query?
...ed Apr 8 at 9:57
Ryabchenko Alexander
3,22711 gold badge1919 silver badges4545 bronze badges
answered May 18 '11 at 13:04
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Simple basic explanation of a Distributed Hash Table (DHT)
...e now independent nodes in a network.
This gives a lot of fault-tolerance and reliability, and possibly some performance benefit, but it also throws up a lot of headaches. For example, what happens when a node leaves the network, by failing or otherwise? And how do you redistribute keys when a node...
Setting JDK in Eclipse
I have two JDKs, for Java 6 and 7.
6 Answers
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