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When should I use a table variable vs temporary table in sql server?
...e some suggestions are below (though the most reliable method is to simply test both with your specific workload).
If you need an index that cannot be created on a table variable then you will of course need a #temporary table. The details of this are version dependant however. For SQL Server 2012...
How to validate an email address in PHP
...ave false positives is something no mortal can do. Check out this list for tests (both failed and succeeded) of the regex used by PHP's filter_var() function.
Even the built-in PHP functions, email clients or servers don't get it right. Still in most cases filter_var is the best option.
If you wa...
Error java.lang.OutOfMemoryError: GC overhead limit exceeded
I get this error message as I execute my JUnit tests:
20 Answers
20
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How do I find the caller of a method using stacktrace or reflection?
...and seems to be faster than the stack trace method.
The following program tests the speed of the different suggested methods (the most interesting bit is in the inner class SecurityManagerMethod):
/**
* Test the speed of various methods for getting the caller class name
*/
public class TestGetCa...
Android - Start service on boot
...d("TAG", "MyReceiver");
Intent serviceIntent = new Intent(context, Test1Service.class);
context.startService(serviceIntent);
}
}
public class Test1Service extends Service {
/** Called when the activity is first created. */
@Override
public void onCreate() {
...
Why is “while ( !feof (file) )” always wrong?
...that actually queries the EOF state: Suppose you have a string and want to test that it represents an integer in its entirety, with no extra bits at the end except whitespace. Using C++ iostreams, it goes like this:
std::string input = " 123 "; // example
std::istringstream iss(input);
...
Static Initialization Blocks
...o matter how many objects of that type you create.
Example:
public class Test {
static{
System.out.println("Static");
}
{
System.out.println("Non-static block");
}
public static void main(String[] args) {
Test t = new Test();
Test t2 = new Tes...
Bash: If/Else statement in one line
... to explicitly check $?. Just do:
ps aux | grep some_proces[s] > /tmp/test.txt && echo 1 || echo 0
Note that this relies on echo not failing, which is certainly not guaranteed. A more reliable way to write this is:
if ps aux | grep some_proces[s] > /tmp/test.txt; then echo 1; el...
Delete all files in directory (but not directory) - one liner solution
...iles from ABC (sub-directories are untouched):
Arrays.stream(new File("C:/test/ABC/").listFiles()).forEach(File::delete);
This deletes only files from ABC (and sub-directories):
Files.walk(Paths.get("C:/test/ABC/"))
.filter(Files::isRegularFile)
.map(Path::toFil...
Multiple Updates in MySQL
...ql warnings into runtime exceptions in your app.
I made some performance tests for three of suggested variants, including the INSERT ... ON DUPLICATE KEY UPDATE variant, a variant with "case / when / then" clause and a naive approach with transaction. You may get the python code and results here. ...