Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>A JIT compiler could theoretically perform a lot of optimizations, yes, but how long are you willing to wait? A C++ app can take hours to compiler because it happens offline, and the user isn't sitting there tapping his fingers and waiting.</p> <p>A JIT compiler has to finish within a couple of milliseconds. So which do you think can get away with the most complex optimizations?</p> <p>The garbage collector is a factor too. Not because it is slower than manual memory management per se (I believe its amortized cost is pretty good, definitely comparable to manual memory handling), but it's less predictable. It <em>can</em> introduce a stall at pretty much any point, which might not be acceptable in systems that are required to be extremely responsive.</p> <p>And of course, the languages lend themselves to different optimizations. C++ allows you to write very tight code, with virtually no memory overhead, and where a lot of high level operations are basically free (say, class construction).</p> <p>In C# on the other hand, you waste a good chunk of memory. And simply instantiating a class carries a good chunk of overhead, as the base <code>Object</code> has to be initialized, even if your actual class is empty.</p> <p>C++ allows the compiler to strip away unused code aggressively. In C#, most of it has to be there so it can be found with reflection.</p> <p>On the other hand, C# doesn't have pointers, which are an optimizing compiler's nightmare. And memory allocations in a managed language are far cheaper than in C++.</p> <p>There are advantages either way, so it is naive to expect that you can get a simple "one or the other" answer. Depending on the exact source code, the compiler, the OS, the hardware it's running on, one or the other may be faster. And depending on your needs, raw performance might not be the #1 goal. Perhaps you're more interested in responsiveness, in avoiding unpredictable stalls.</p> <p>In general, your typical C++ code will perform <em>similarly</em> to equivalent C# code. Sometimes faster, sometimes slower, but probably not a dramatic difference either way.</p> <p>But again, it depends on the exact circumstances. And it depends on how much time you're willing to spend on optimization. if you're willing to spend as much time as it takes, C++ code can usually achieve better performance than C#. It just takes a lot of work.</p> <p>And the other reason, of course, is that most companies who use C++ already have a large C++ code base which they don't particularly want to ditch. They need that to keep working, even if they gradually migrate (some) new components to a managed language.</p>
    singulars
    1. This table or related slice is empty.
    1. POPerformance of C++ vs Virtual Machine languages in high frequency finance
      singulars
      1. PTQuestion
    1. PTAnswer
    1. This table or related slice is empty.
    1. USjalf
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COjaif - JIT compilers can cache their results (ie .Net) so that you only get a hit on the first execution. Also in the case of .Net they can optimize on a per machine basis from a single source code base - something that a static compiler can't do. I'd be surpised if Java didn't do similar things
      singulars
      1. PO
      1. USPeter M
    2. CO@Peter M: Sure a static compiler can do that. For example, if you want to increase speed on platforms with SSE, a compiler could include both code that uses SSE and code that does not.
      singulars
      1. PO
      1. USBilly ONeal
    3. CO@Peter: yes, but most users are not willing to add 2 hours to their startup time, is my point. Cached or not, the problem is that advanced optimizations take time, and no matter how aggressively you cache, they have to be performed at least once.
      singulars
      1. PO
      1. USjalf
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload