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In SQL, what's the difference between count(column) and count(*)?
...column) does not
[edit] added this code so that people can run it
create table #bla(id int,id2 int)
insert #bla values(null,null)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,1)
insert #bla values(1,null)
insert #bla values(null,null)
se...
CUDA incompatible with my gcc version
...l directory and then make symbolic links to the supported gcc version executables. Pass that local directory to nvcc via the --compiler-bindir option, and you should be able to compile CUDA code without affecting the rest of your system.
EDIT:
Note that this question, and answer, pertain to CUDA...
What requests do browsers' “F5” and “Ctrl + F5” refreshes generate?
...trol by adding "Pragma: No-cache" when you pressed CTRL-F5.
Edit: Updated table
The table below is updated with information on what will happen when the browser's refresh-button is clicked (after a request by Joel Coehoorn), and the "max-age=0" Cache-control-header.
Updated table, 27 September 20...
Client-server synchronization pattern / algorithm?
...g every change (insert, update or delete) from any device into a "history" table. So if, for example, someone changes their phone number in the "contact" table, the system will edit the contact.phone field, and also add a history record with action=update, table=contact, field=phone, record=[contact...
Meaning of Open hashing and Closed hashing
... us the index (aka. address) at which an object will be stored in the hash table is not completely determined by its hash code. Instead, the index may vary depending on what's already in the hash table.
The "closed" in "closed hashing" refers to the fact that we never leave the hash table; every...
How to play audio?
...ats as HTML5’s <audio>. Wikipedia has a audio format compatibility table. new Audio() can play WAV files in all browsers except Internet Explorer.
– Rory O'Kane
Mar 15 '15 at 14:18
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Why do you create a View in a database?
...ews can hide complexity
If you have a query that requires joining several tables, or has complex logic or calculations, you can code all that logic into a view, then select from the view just like you would a table.
2. Views can be used as a security mechanism
A view can select certain columns an...
PHP function to make slug (URL string)
...
sanitize is a strange, forgettable function name to generate a slug.
– rybo111
Jul 3 '15 at 13:52
add a comment
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SQL Joins Vs SQL Subqueries (Performance)?
...ies with Semijoin Transformations
Rewriting Subqueries as Joins
I have a table with 50000 elements, the result i was looking for was 739 elements.
My query at first was this:
SELECT p.id,
p.fixedId,
p.azienda_id,
p.categoria_id,
p.linea,
p.tipo,
p.nome
FROM prodotto p
WH...
When to use a View instead of a Table?
When should a View actually be used over an actual Table? What gains should I expect this to produce?
8 Answers
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