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COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
... are using as well as the type of table in some cases.
For example, using MySQL, count(*) will be fast under a MyISAM table but slow under an InnoDB. Under InnoDB you should use count(1) or count(pk).
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ActiveRecord: List columns in table from console
...console. It will enter the shell of your database, whether it is sqlite or mysql.
Then, you can query the table columns using sql command like:
pragma table_info(your_table);
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Difference between static STATIC_URL and STATIC_ROOT on Django
I am confused by static root and want to clarify things.
3 Answers
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How to list running screen sessions?
...ntle ~ # ls -laR /var/run/screen/
/var/run/screen/:
total 1
drwxrwxr-x 4 root utmp 96 Mar 1 2005 .
drwxr-xr-x 10 root root 840 Feb 1 03:10 ..
drwx------ 2 josh users 88 Jan 13 11:33 S-josh
drwx------ 2 root root 48 Feb 11 10:50 S-root
/var/run/screen/S-josh:
total 0
drwx------ 2 josh u...
CSS background-image - What is the correct usage?
...out of the CSS folder tree you should use absolute path or relative to the root path (starting with /)
3) you should use complete declaration for background-image to make it behave consistently across standards compliant browsers like:
background:blue url('/images/clouds.jpg') no-repeat scroll lef...
Why does LayoutInflater ignore the layout_width and layout_height layout parameters I've specified?
...resource: ID for an XML layout resource to load (e.g., R.layout.main_page)
root: Optional view to be the parent of the generated hierarchy (if attachToRoot is true), or else simply an object that provides a set of LayoutParams values for root of the returned hierarchy (if attachToRoot is false.)
att...
Is there a library function for Root mean square error (RMSE) in python?
I know I could implement a root mean squared error function like this:
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How can I create a self-signed cert for localhost?
...cking around, you can do: sudo security add-trusted-cert -p ssl -d -r trustRoot -k ~/Library/Keychains/login.keychain localhost.crt
– philfreo
Apr 8 '16 at 0:50
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How to prevent blank xmlns attributes in output from .NET's XmlDocument?
...ng around, I figured out how to remove blank xmlns attributes: pass in the root node's namespace when creating any child node you want not to have a prefix on. Using a namespace without a prefix at the root means that you need to use that same namespace on child elements for them to also not have p...
Converting an integer to a string in PHP
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Good point. I threw in some mysql_escape_string functions in there to clean it up.
– Chris Thompson
Jun 23 '09 at 23:33
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