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When and why are database joins expensive?
...s back to mitigating the size of the working set. Joins involving properly selected keys with correctly set up indexes are cheap, not expensive, because they allow significant pruning of the result before the rows are materialised.
Materialising the result involves bulk disk reads which are the mo...
What does each of the [y,n,q,a,d,/,K,j,J,g,e,?] stand for in context of git -p
...lowing
patch
This lets you choose one path out of a status like selection. After choosing the path, it presents the diff between the index and the working tree file and asks you if you want to stage the change of each hunk. You can select one of the following options and type return:
...
How to make all Objects in AWS S3 bucket public by default?
...n.s3.amazonaws.com/policygen.html
Fill in the details such as:
In Action select "GetObject"
Select "Add Statement"
Then select "Generate Policy"
Copy the text example:
{
"Id": "Policy1397632521960",
"Statement": [
{
"Sid": "Stmt1397633323327",
"Action": [
"s3:GetObjec...
Eclipse “Server Locations” section disabled and need to change to use Tomcat installation
...
Here is how I did it:
Right click on my tomcat server in "Servers" view, select "Properties…"
In the "General" panel, click on the "Switch Location" button
The "Location: [workspace metadata]" bit should have been replaced by something else.
Open (or close and reopen) the Overview screen for the...
ListCtrl 重绘（Custom Draw） - C/C++ - 清泛网 - 专注C/C++及内核技术
...绘制的SubItem的Index值
l 正被绘制的Item的状态值（selected, grayed, 等等）
l Item的LPARAM值，就是你使用CListCtrl::SetItemData所设的那个值
上述所有的信息对你来说可能都很重要，这取决于你想实现什么效果，但最经常用到...
Xcode 4.4 error - Timed out waiting for app to launch
...
I was trying to debug with a Enterprise Dist cert selected. Switched back to my development cert and the issue was resolved-- thanks!
– RyanG
Nov 19 '12 at 20:15
...
Error: CUICatalog: Invalid asset name supplied: (null), or invalid scale factor : 2.000000
...
In Xcode 6.4, this seems to occur when using "Selected Image" for a tab bar item in the storyboard, even if it's a valid image.
This doesn't actually seem to set the selected state image anyway, so it needs to be defined in User Defined Runtime Attributes, and removed...
Can I bind an array to an IN() condition?
...(0, count($ids), '?'));
$db = new PDO(...);
$stmt = $db->prepare(
'SELECT *
FROM table
WHERE id IN(' . $inQuery . ')'
);
// bindvalue is 1-indexed, so $k+1
foreach ($ids as $k => $id)
$stmt->bindValue(($k+1), $id);
$stmt->execute();
?>
fix: dan, you were right. ...
How to check if a function exists on a SQL database
...hat SSMS uses when you script using the DROP and CREATE option
IF EXISTS (SELECT *
FROM sys.objects
WHERE object_id = OBJECT_ID(N'[dbo].[foo]')
AND type IN ( N'FN', N'IF', N'TF', N'FS', N'FT' ))
DROP FUNCTION [dbo].[foo]
GO
This approach to deploying...
how to display full stored procedure code?
...
SELECT prosrc FROM pg_proc WHERE proname = 'function_name';
This tells the function handler how to invoke the function. It might be the actual source code of the function for interpreted languages, a link symbol, a file nam...