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How to make Java honor the DNS Caching Timeout?
...d a fixed domain name. Through some DNS magic, the domain name is resolved into an IP that's closest to the server with least load. For the load-balancing to work, the application server needs to honor the TTL from DNS response and to resolve the domain name again when cache times out. However, I co...
How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...quence of commands should do the trick:
ALTER TABLE test1 ADD COLUMN id INTEGER;
CREATE SEQUENCE test_id_seq OWNED BY test1.id;
ALTER TABLE test ALTER COLUMN id SET DEFAULT nextval('test_id_seq');
UPDATE test1 SET id = nextval('test_id_seq');
Again, in recent versions of Postgres this is ...
C++ static virtual members?
... think that static virtuals are meaningful. It would be possible to define interface classes and include static methods that have to be implemented in derived class.
– bkausbk
Jan 24 '13 at 7:43
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Simplest way to serve static data from outside the application server in a Java web application
...n some suggestions like having the image directory being a symbolic link pointing to a directory outside the web container, but will this approach work both on Windows and *nix environments?
If you adhere the *nix filesystem path rules (i.e. you use exclusively forward slashes as in /path/to/files)...
How to create a temporary directory?
...
Good point, updated the script to check if the temp dir could be created.
– Ortwin Angermeier
Mar 7 '17 at 17:02
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HashMap get/put complexity
...epends on the hash implementation. The default object hash is actually the internal address in the JVM heap. Are we sure it is good enough to claim that the get/put are O(1) ?
...
What's the best way to share data between activities?
...Here a compilation of most common ways to achieve this:
Send data inside intent
Static fields
HashMap of WeakReferences
Persist objects (sqlite, share preferences, file, etc.)
TL;DR: there are two ways of sharing data: passing data in the intent's extras or saving it somewhere else. If data is p...
What is tail recursion?
...sum(x - 1);
}
}
If you called recsum(5), this is what the JavaScript interpreter would evaluate:
recsum(5)
5 + recsum(4)
5 + (4 + recsum(3))
5 + (4 + (3 + recsum(2)))
5 + (4 + (3 + (2 + recsum(1))))
5 + (4 + (3 + (2 + 1)))
15
Note how every recursive call has to complete before the JavaScri...
Android preferences onclick event
...referenceClick(Preference preference) {
//open browser or intent here
return true;
}
});
share
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improve this answer
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Naming of ID columns in database tables
...
Agree, and you point out the main reason not use "id" ,because the we always have table alias such as "i" for inoice, p for "product" on SQL or LINQ etc.
– Cheung
Oct 13 '14 at 7:50
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