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Write a program to find 100 largest numbers out of an array of 1 billion numbers
...ulate this probability. For example, lets assume the numbers were randomly selected uniformly from {0, 1}, the expected value of (i-K)th number (out of i numbers) is (i-k)/i, and chance of a random variable being larger than this value is 1-[(i-k)/i] = k/i.
Thus, the expected number of insertions ...
How do I create a unique constraint that also allows nulls?
...dy found separately in other, properly defined columns. It should never be selected or used.
So, my story is that this is not a surrogate NULL, and I'm sticking to it! Since we don't actually want the non-NULL value for any purpose other than to trick the UNIQUE index to ignore NULLs, our use case ...
Why use the params keyword?
...
You could also use return args.Select(x => x + 2).Sum();
– bbvg
Aug 22 '17 at 21:07
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How to speed up insertion performance in PostgreSQL
...rypto module) is (a lot) faster than uuid_generate_v4()
=# explain analyze select uuid_generate_v4(),* from generate_series(1,10000);
QUERY PLAN
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How to specify font attributes for all elements on an html web page?
...es use: *,:before,:after{font-family:inherit;} if you must use a universal selector, use inheritance instead.
– darcher
Jun 5 '15 at 16:15
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How to map a composite key with JPA and Hibernate?
... way you write queries (making them more or less verbose):
with IdClass
select t.levelStation from Time t
with EmbeddedId
select t.timePK.levelStation from Time t
References
JPA 1.0 specification
Section 2.1.4 "Primary Keys and Entity Identity"
Section 9.1.14 "EmbeddedId Annotation"
Sect...
I have an error: setOnItemClickListener cannot be used with a spinner, what is wrong?
...nner.
setOnItemClickListener cannot be used with a Spinner. Use setOnItemSelectedListener instead.
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How can I tell if my server is serving GZipped content?
...erested). You can tell using Developer Tools (F12). Go to the Network tab, select the file you want to examine and then look at the Headers tab on the right. If you are gzipped, then you will see that in the Content-Encoding.
In this example, slider.jpg is indeed being gzipped.
Compare that to t...
How to store arrays in MySQL?
... retrieve a person and all of their fruit you can do something like this:
SELECT p.*, f.*
FROM person p
INNER JOIN person_fruit pf
ON pf.person_id = p.id
INNER JOIN fruits f
ON f.fruit_name = pf.fruit_name
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SQLite table constraint - unique on multiple columns
...Some other title');
sqlite> .mode col
sqlite> .headers on
sqlite> select * from t1;
id a b
---------- ---------- ----------------
1 Alice Some other title
2 Bob Palindromic guy
3 Charles chucky cheese
sq...