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How does database indexing work? [closed]
..., huh?
Now, imagine you want to find a particular Chapter that contains a word "Alchemist". Without an index page, you have no other option than scanning through the entire book/Chapters. i.e: 1000 pages.
This analogy is known as "Full Table Scan" in database world.
But with an index page, you...
Which cryptographic hash function should I choose?
... needing one or more of these properties. A hash function for securing passwords on a server will usually only require preimage resistance, while message digests require all three.
It has been shown that MD5 is not collision resistant, however, that does not preclude its use in applications that do...
List of ANSI color escape sequences
...ween languages are also interesting: note the profusion of distinct colour words used by English vs. Chinese. However, digging deeper into these languages shows that each uses colour in distinct ways. (More information)
Generally speaking, the naming, use, and grouping of colours in human languages...
Why doesn't c++ have &&= or ||= for booleans?
...ce the right-hand side to convert to bool, which &= does not. In other words, bool b = true; b &= 2; results in b == false.
– Angew is no longer proud of SO
Nov 10 '16 at 14:02
...
“is” operator behaves unexpectedly with integers
...NEL_SINGLETON = object() # this will only be created one time.
def foo(keyword_argument=None):
if keyword_argument is None:
print('no argument given to foo')
bar()
bar(keyword_argument)
bar('baz')
def bar(keyword_argument=SENTINEL_SINGLETON):
# SENTINEL_SINGLETON tells ...
CSS selector for first element with class
... exactly what it means, and it's why this answer is flawed. The reason the word "type" was chosen is so as not to couple Selectors with HTML/XML, since not all languages have a concept of "tags" that define elements.
– BoltClock♦
Jul 6 '17 at 3:29
...
Clustered vs Non-Clustered
... index determines the physical order of the rows in the database. In other words, applying the clustered index to PersonId means that the rows will be physically sorted by PersonId in the table, allowing an index search on this to go straight to the row (rather than a non-clustered index, which woul...
Optimizing away a “while(1);” in C++0x
...d discussion by one of the answers, it is written that "Unfortunately, the words 'undefined behavior' are not used. However, anytime the standard says 'the compiler may assume P,' it is implied that a program which has the property not-P has undefined semantics." . This surprises me. Does this mean ...
Difference between Repository and Service Layer?
...teUser(int id);
IQueryable<User> ListUsers();
bool ChangePassword(string userName, string newPassword);
bool SendPasswordReminder(string userName);
bool RegisterNewUser(RegisterNewUserModel model);
}
While List() method of repository returns all users, ListUsers() of IUserSer...
How to implement has_many :through relationships with Mongoid and mongodb?
...ude Mongoid::Document
has_and_belongs_to_many :physicians
end
In other words you would eliminate the join table and it would have a similar effect to has_many :through in terms of access to the 'other side'. But in your case thats probably not appropriate because your join table is an Appointmen...