大约有 30,600 项符合查询结果（耗时：0.0325秒） [XML]
Storing time-series data, relational or non?
...Device, Metric, DateTime)
The Id column does nothing, it is totally and completely redundant.
An Id column is never a Key (duplicate rows, which are prohibited in a Relational database, must be prevented by other means).
The Id column requires an additional Index, which obviously impedes th...
Is a view faster than a simple query?
...w." However, this is easily refuted.
Let us say that we are a software company in a small country; I'll use Lithuania as an example. We sell software worldwide and keep our records in a SQL Server database. We're very successful and so, in a few years, we have 1,000,000+ records. However, we ...
iPhone App Icons - Exact Radius?
...ns is greater then it will show black around the edges/corners.
Edit: See comment from @devin-g-rhode and you can see that any future icon sizes should have a 1:6.4 ratio of corner radius to icon size. There is also a very good answer from https://stackoverflow.com/a/29550364/396005 which has the ...
System.Threading.Timer in C# it seems to be not working. It runs very fast every 3 second
...sed. Then in your Callback function you Change the timer once the work has completed, not before. Example:
private void Callback( Object state )
{
// Long running operation
_timer.Change( TIME_INTERVAL_IN_MILLISECONDS, Timeout.Infinite );
}
Thus there is no need for locking mechanisms beca...
multiprocessing: sharing a large read-only object between processes?
...ffers between the processes.
Solution 2
In some cases, you have a more complex structure – often a "fan-out" structure. In this case you have a parent with multiple children.
Parent opens source data. Parent forks a number of children.
Parent reads source, farms parts of the source out to ...
First-time database design: am I overengineering? [closed]
...turn data. Not only does a report server function have more tolerance for complex and lengthy queries, but the strategies to improve performance are much different.
For example, in a transaction based application environment your performance improvement options might include refactoring your sto...
Can a Windows batch file determine its own file name?
...
add a comment
|
48
...
How do I fix blurry text in my HTML5 canvas?
...etween pixels to display the element at its proper size.
I would highly recommend you read this article from HTML5Rocks which explains in more detail how to create high definition elements.
tl;dr?
Here is an example (based on the above tut) that I use in my own projects to spit out a canvas with t...
How do the likely/unlikely macros in the Linux kernel work and what is their benefit?
...
They are hint to the compiler to emit instructions that will cause branch prediction to favour the "likely" side of a jump instruction. This can be a big win, if the prediction is correct it means that the jump instruction is basically free and w...
Should operator
...p < > <= >=
These operators should return a bool as they are comparing two objects of the same type. It is usually easiest to define these operators as part of the class. This is because a class is automatically a friend of itself so objects of type Paragraph can examine each other (ev...