Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>It totally depends on what you need to do. There is no general aversion to using statics. Note that statics are essentially the singleton pattern, so all the pros/cons about singletons apply.</p> <p>In terms of threads you have to pay attention since the same instance could be access by multiple threads at the same time. If you only need to read the data then you shouldn't have any problems. If you need to modify the data you have to worry about synchronization.</p> <p>For code reuse and testing singeltons can often pose a problem. You can't for example recreate the object in a test, or have multiple run in parallel. In general when I use singletons/statics I try to ensure that one instance of the entire life of all tests, parallel executions, etc. is totally okay.</p> <p><em>Invisible</em> statics as you call them (visible only to the compilation unit) are a <em>good</em> idea. This helps you maintain synchronization between threads and manage them correctly. If they have global visibility then they can be modified at any time (well private variables can't, so they are also good).</p> <hr> <p>Also note that atomic variables can be safely read/written from various threads. For simple counters this is often a good solution: using atomic increment. In C++0x you can use "atomic", previously use your OS/compiler function that does it. As with the singleton pattern, you can easily design classes where each function is synchronized so the singleton user doesn't have to worry about it. That is to say, statics aren't inherently thread-safe even when doing writing.</p>
    singulars
    1. This table or related slice is empty.
    1. POWhy using static namespace/class member variables is a bad idea in C++?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USedA-qa mort-ora-y
    1. USedA-qa mort-ora-y
    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. CO+1 for "It totally depends on what you need to do"
      singulars
      1. PO
      1. USKiril Kirov
    2. CO"If you only need to read the data then you shouldn't have any problems"... in general, you can't read data safely while another thread's updating it. Whether the programmer always feels that every "an/other thread" is theirs in the sense of ownership "you" implies is doubtful. Even for `int`, you can miss updates if you don't use something to sync caches....
      singulars
      1. PO
      1. USTony Delroy
    3. CO@Tony, I said **only** need to **read**. Of course you can't write to it without synchronization. But that's what I said in the sentence after...?
      singulars
      1. PO
      1. USedA-qa mort-ora-y
 

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