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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...
Subqueries vs joins
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Here's an example of how subqueries are evaluated in MySQL 6.0.
The new optimizer will convert this kind of subqueries into joins.
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Deploying my application at the root in Tomcat
I have the war file of my application. I need to deploy this at the root level. The current URL is http://localhost:8080/war_name/application_name .
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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 get root access on Android emulator?
...roid SDK versions(from 1.5 to 2.3.3), and I tried many methods for getting root in Android emulator. I don't use any Android device and test everything on emulator(AVD).
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Select something that has more/less than x character
...nks.
Here's the link to the MSDN
For oracle/plsql you can use Length(), mysql also uses Length.
Here is the Oracle documentation:
http://www.techonthenet.com/oracle/functions/length.php
And here is the mySQL Documentation of Length(string):
http://dev.mysql.com/doc/refman/5.1/en/string-functi...
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...
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 ...
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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In JPA 2, using a CriteriaQuery, how to count results
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Mind you that the qb.count is done over the Root<MyEntity> of your query (Root<MyEntity> myEntity = cq.from(MyEntity.class)) and this is often already in your normal select code and when you forget you end up with a join to self.
– gke...