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What's the difference between an inverted index and a plain old index?
...bove - a list of words, and where to find them in the book. In a book, the table of contents is like a forward index: it's a list of documents (chapters) which the book contains, except instead of listing the words in those sections, the table of contents just gives a name/general description of wha...
What's the difference between session.persist() and session.save() in Hibernate?
... does not cascade to the child, i.e., only Parent is saved/inserted in the table. However, persist accomplished the task of saving both Parent and Child in one call. I am using a composite ID not a generated ID.
– arn-arn
Aug 11 '16 at 14:05
...
Combine two ActiveRecord::Relation objects
...ny odd situations, by using Rails' built-in Arel.
User.where(
User.arel_table[:first_name].eq('Tobias').or(
User.arel_table[:last_name].eq('Fünke')
)
)
This merges both ActiveRecord relations by using Arel's or.
Merge, as was suggested here, didn't work for me. It dropped the 2nd set...
JavaScript + Unicode regexes
...ate, and Escape check boxes, which strike a balance between avoiding unprintable characters and minimizing the size of the regex.
Here are some common expansions of different Unicode properties:
\p{L} (Letters):
[A-Za-z\u00AA\u00B5\u00BA\u00C0-\u00D6\u00D8-\u00F6\u00F8-\u02C1\u02C6-\u02D1\u02E0-\...
Find XOR of all numbers in a given range
...f() function calculates the XOR total run from [0, a]. Take a look at this table for 4-bit numbers:
0000 <- 0 [a]
0001 <- 1 [1]
0010 <- 3 [a+1]
0011 <- 0 [0]
0100 <- 4 [a]
0101 <- 1 [1]
0110 <- 7 [a+1]
0111 <- 0 [0]
1000 <- 8 [a]
1001 <- 1 [1]
1010 <- 11 [...
Where and how is the _ViewStart.cshtml layout file linked?
...ing on what type of device is accessing the site –
and have a phone or tablet optimized layout for those devices, and a
desktop optimized layout for PCs/Laptops. Or if we were building a
CMS system or common shared app that is used across multiple customers
we could select different layou...
How does JPA orphanRemoval=true differ from the ON DELETE CASCADE DML clause
... i call department.remove(emp); that employee will be deleted from the emp table without even calling commit()
– JavaTechnical
Jun 10 '14 at 12:00
add a comment
...
Difference between float and decimal data type
...
This is what I found when I had this doubt.
mysql> create table numbers (a decimal(10,2), b float);
mysql> insert into numbers values (100, 100);
mysql> select @a := (a/3), @b := (b/3), @a * 3, @b * 3 from numbers \G
*************************** 1. row *************************...
Undefined reference to `sin` [duplicate]
...As a result, you can compile your .o object files, but not build your executable.
As Paul has already mentioned add "-lm" to link with the math library in the step where you are attempting to generate your executable.
In the comment, linuxD asks:
Why for sin() in <math.h>, do we need -lm...
Android static object lifecycle
...tarts a process and assigns it a unique process id and allocates a process table.A process start an instance of DVM(Dalvik VM); Each application runs inside a DVM.
A DVM manages class loading unloading, instance lifecycle, GC etc.
Lifetime of a static variable: A static variable comes into existenc...