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Is storing a delimited list in a database column really that bad?
...ient table-scan. May have to resort to regular expressions, for example in MySQL:
idlist REGEXP '[[:<:]]2[[:>:]]'*
Hard to count elements in the list, or do other aggregate queries.
Hard to join the values to the lookup table they reference.
Hard to fetch the list in sorted order.
To solve th...
How do I do an OR filter in a Django query?
...ke me) where | being used as OR operator comes from, it's actually the set union operator. It's also used (not here) as bitwise OR: stackoverflow.com/questions/5988665/pipe-character-in-python
– e100
Mar 26 '15 at 18:06
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Merging dictionaries in C#
...t; allTables = new Dictionary<String, String>();
allTables = tables1.Union(tables2).ToDictionary(pair => pair.Key, pair => pair.Value);
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What is sharding and why is it important?
...cross multiple logical or physical nodes (in the case of my understanding (mySQL) multiple databases, most likely housed on different logical hardware). Horizontal partitioning is a less specific term, of which "Sharding" is a subset. Again using mySQL as an example, a mySQL partition is handled by...
How to check if running as root in a bash script
I'm writing a script that requires root level permissions, and I want to make it so that if the script is not run as root, it simply echoes "Please run as root." and exits.
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Is bool a native C type?
...goto
if
int
long
register
return
short
signed
static
struct
switch
typedef
union
unsigned
void
volatile
while
Here's an article discussing some other differences with C as used in the kernel and the standard: http://www.ibm.com/developerworks/linux/library/l-gcc-hacks/index.html
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how to change default python version?
...meworks/Python.framework/Versions/3.2/bin/
$ ls -l
total 384
lrwxr-xr-x 1 root admin 8 Apr 28 15:51 2to3@ -> 2to3-3.2
-rwxrwxr-x 1 root admin 140 Feb 20 11:14 2to3-3.2*
lrwxr-xr-x 1 root admin 7 Apr 28 15:51 idle3@ -> idle3.2
-rwxrwxr-x 1 root admin 138 Feb 20 11:14 idl...
Count the occurrences of DISTINCT values
I am trying to find a MySQL query that will find DISTINCT values in a particular field, count the number of occurrences of that value and then order the results by the count.
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When NOT to use Cassandra?
...ase of RDBMS, making a choice is quite easy because all the databases like MySQL, Oracle, MS SQL, PostgreSQL in this category offer almost the same kind of solutions oriented toward ACID properties. When it comes to NoSQL, the decision becomes difficult because every NoSQL database offers different ...
Determine if running on a rooted device
...has a certain piece of functionality that will only work on a device where root is available. Rather than having this feature fail when it is used (and then show an appropriate error message to the user), I'd prefer an ability to silently check if root is available first, and if not,hide the respect...