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What is PAGEIOLATCH_SH wait type in SQL Server?
...ppens in queries that use indexes efficiently.
If your query is like this:
Select * from <table> where <col1> = <value> order by <PrimaryKey>
, check that you have a composite index on (col1, col_primary_key).
If you don't have one, then you'll need either a full INDEX SCAN ...
Slicing of a NumPy 2d array, or how do I extract an mxm submatrix from an nxn array (n>m)?
I want to slice a NumPy nxn array. I want to extract an arbitrary selection of m rows and columns of that array (i.e. without any pattern in the numbers of rows/columns), making it a new, mxm array. For this example let us say the array is 4x4 and I want to extract a 2x2 array from it.
...
Local file access with JavaScript
...
If the user selects a file via <input type="file">, you can read and process that file using the File API.
Reading or writing arbitrary files is not allowed by design. It's a violation of the sandbox. From Wikipedia -> Javascri...
#1071 - Specified key was too long; max key length is 1000 bytes
... the best prefix length for a given column? Here's a method to find out:
SELECT
ROUND(SUM(LENGTH(`menu_link`)<10)*100/COUNT(`menu_link`),2) AS pct_length_10,
ROUND(SUM(LENGTH(`menu_link`)<20)*100/COUNT(`menu_link`),2) AS pct_length_20,
ROUND(SUM(LENGTH(`menu_link`)<50)*100/COUNT(`menu_...
How to view revision history for Mercurial file?
...a while to figure out how. You need to right-click on the desired file and select "File History". However, for some mysterious reason, the file needs to be unaltered. Furthermore, to find the desired file there are two options:
In ### revision set query### one can type:
file("**<myfile>")
...
Really weird eclipse keyboard behavior/bug?
.... They worked in other applications. Option-Arrows worked fine to move a selection around. Arrows worked in the keyboard preferences window. Switching to another application and back didn't work. Restarting eclipse made no difference. Switching keyboard schemes from Emacs -> Default -> E...
How do I return rows with a specific value first?
...to treat boolean expressions as having a numeric value, then you can use:
SELECT *
FROM `Users`
ORDER BY (`city` = 'New York') DESC, `city`
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How do I undo “Scope to this” in Visual Studio 2012?
...orward and back buttons.
Extra:
You can also right click on projects and select 'New Solution Explorer Window' to have two separate solution explorers which can browse independently (note that changing the settings on one will effect the other).
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How to edit one specific row in Microsoft SQL Server Management Studio 2008?
...rver Management Studio 2008/2012/2014/2016
Step 1: Right button mouse > Select "Edit Top 200 Rows"
Step 2: Navigate to Query Designer > Pane > SQL (Shortcut: Ctrl+3)
Step 3: Modify the query
Step 4: Right button mouse > Select "Execute SQL" (Shortcut: Ctrl+R)
...
How to delete all datastore in Google App Engine?
...hboard for your app (login on appengine) then datastore --> dataviewer, select all the rows for the table you want to delete and hit the delete button (you'll have to do this for all your tables).
You can do the same programmatically through the remote_api (but I never used it).
If you're talki...