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PostgreSQL: Difference between text and varchar (character varying)
...array).
Check this article from Depesz: http://www.depesz.com/index.php/2010/03/02/charx-vs-varcharx-vs-varchar-vs-text/
A couple of highlights:
To sum it all up:
char(n) – takes too much space when dealing with values shorter than n (pads them to n), and can lead to subtle errors be...
Equivalent of varchar(max) in MySQL?
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197
The max length of a varchar is subject to the max row size in MySQL, which is 64KB (not counti...
Git clone without .git directory
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Use
git clone --depth=1 --branch=master git://someserver/somerepo dirformynewrepo
rm -rf ./dirformynewrepo/.git
The depth option will make sure to copy the least bit of history possible to get that repo.
The branch option is optional and if not...
How to select lines between two marker patterns which may occur multiple times with awk/sed
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191
Use awk with a flag to trigger the print when necessary:
$ awk '/abc/{flag=1;next}/mno/{flag=...
ansible: lineinfile for several lines?
...ith_items:
- { regexp: '^kernel.shmall', line: 'kernel.shmall = 2097152' }
- { regexp: '^kernel.shmmax', line: 'kernel.shmmax = 134217728' }
- { regexp: '^fs.file-max', line: 'fs.file-max = 65536' }
sha...
How to calculate age (in years) based on Date of Birth and getDate()
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How do you print in a Go test using the “testing” package?
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148
The structs testing.T and testing.B both have a .Log and .Logf method that sound to be what yo...
How do I move a redis database from one server to another?
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12 Answers
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When should I use a composite index?
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112
You should use a composite index when you are using queries that benefit from it. A composite ...