Questions regarding efficient storing and representing data within a software application.

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1
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2answers
770 views

What is the underlying mechanism behind va_list and where is it defined?

http://www.cplusplus.com/reference/cstdarg/va_list/ According to the above link, va_list is an argument or parameter used in some macros - va_start, va_arg, va_end. These macros are present in the ...
4
votes
3answers
2k views

Data Oriented Design - impractical with more than 1-2 structure “members”?

The usual example of Data Oriented Design is with the Ball structure: struct Ball { float Radius; float XYZ[3]; }; and then they make some algorithm that iterates a std::vector<Ball> ...
2
votes
2answers
486 views

Best way of storing a small number of user credentials

I'm working on a messaging application, based on a server/client architecture. Now I am thinking about the way how to store the user credentials. It's not a huge number, just about 20 entries with ...
0
votes
2answers
207 views

High-level strategy for distinguishing a regular string from invalid JSON (ie. JSON-like string detection)

Disclaimer On Absence of Code: I have no code to post because I haven't started writing; was looking for more theoretical guidance as I doubt I'll have trouble coding it but am pretty befuddled on ...
15
votes
4answers
8k views

EAV - is it really bad in all scenarios?

I'm thinking to use EAV for some of the stuff in one of the projects, but all questions about it in stackoverflow end up to answers calling EAV an anti pattern. But I'm wondering, if is it that wrong ...
5
votes
2answers
674 views

Overriding GetHashCode in a mutable struct - What NOT to do?

I am using the XNA Framework to make a learning project. It has a Point struct which exposes an X and Y value; for the purpose of optimization, it breaks the rules for proper struct design, since its ...
0
votes
1answer
462 views

What data structure is suitable for implementing dynamic huffman encoding and decoding on a piece of text?

Some pseudo code or resources will be appreciated.I was thinking if implementing it in form of a BST stored in an array. However,not all operations can be performed easily using this approach. I am ...
22
votes
2answers
830 views

Is there a data structure for this type of list/map?

Perhaps there's a name for what I want, but I'm not aware of it. I need something similar to a LinkedHashMap in Java, but where it returns the 'previous' value if there's no value at the specified ...
1
vote
4answers
757 views

Data structure for file search

I've asked this question before and I got a few answers/idea, but I'm not sure how to implement them. I'm building a telecom messaging solution. Currently, I'm using a database to save my ...
3
votes
2answers
504 views

Data structure for grid with negative indeces

Sorry if this is an insultingly obvious concept, but it's something I haven't done before and I've been unable to find any material discussing the best way to approach it. I'm wondering what's the ...
2
votes
1answer
343 views

Where to implement thread-safety logic for my queue data structure?

I will immediately confess that I do very little multithreading, so questions of style and organization in this domain a little fresh to me. I've written a data structure (in Python, if that matters) ...
10
votes
2answers
881 views

Ideal data structure for storing map data?

I was asked this in an interview test. I did okay on the test but didn't know enough to answer this question. I am curious to know what data structures I can use to query the data quickly. Basically ...
1
vote
1answer
40 views

Benefits of caching the count of items in a data structure versus on-demand calculation?

Given a data structure, I want to provide an API method Size which returns the number of items. I am vacillating between 2 approaches: Maintain a count and increment/decrement it in response to ...
6
votes
1answer
494 views

Min cost concatenation alignment [closed]

I am doing a project on data mining. I have a very large string of size, say n and many small strings, l_1,l_2.. each of size at most m. I want to find the sequence of small strings such that their ...
1
vote
3answers
368 views

Choice between 1-dimensional and 2-dimensional array

I'm implementing the Chessboard class to represent the chessboard. I've to implement the transformations (reflections and rotations) on the chess board possible. The possible transformations includes ...
-2
votes
1answer
375 views

Does implementing algorithms improve your programming skills? [duplicate]

I have been self studying algorithms and data structures for some time now and currently enjoying it. Whenever I understand an algorithm, I usually try to code them from scratch for fun and I always ...
0
votes
1answer
357 views

How does Google store its PageRank matrix?

I'm curious to know how Google stores the matrix that's used in the PageRank algorithm; and am looking for a data-structure for storing a very-large (not fitting in memory of any one computer) sparse ...
1
vote
2answers
2k views

Equivalent of #map in ruby in golang

I'm playing with Go and run into something I'm unable to find in Google, although there is certainly something that exists: I'm using the following struct: type Syntax struct { name string ...
3
votes
6answers
2k views

How did programmers implement Linked list ideas before the object oriented paradigm?

Linked lists, as far as I have seen, are largely implemented using object-oriented ideas. (having an object that holds some information and the address of the next link). How were Linked-lists ...
1
vote
3answers
335 views

what is the javascript internal data structure?

Consider a basic js object: var obj={x:1,y:'2'}; Is this stored internally as a hashtable or does js use a different mechanism for key value pairs? If they are hash tables does anyone know how they ...
0
votes
1answer
767 views

What happens to equal elements when inserting into a binary search tree?

Most BST examples show a sample of a BST with unique values; mainly to demonstrate the order of values. e.g. values in the left subtree are smaller than the root, and values in the right subtree are ...
5
votes
6answers
5k views

Why is the usage of string keys generally considered to be a bad idea?

This has been bugging me for a while. Most of the time, when it comes to storing data in structures such as hashtables, programmers, books and articles insist that indexing elements in said structures ...
24
votes
7answers
4k views

Should I keep investing into data structures and algorithms? [closed]

These days, I'm investing heavily in data structures and algorithms and trying to solve some programming puzzles. I'm trying to code and solve with Java and Clojure. Am I wasting my time? should I ...
5
votes
7answers
1k views

Priority list of tasks stored in a database

I am trying to think of the best way to do the following: I have a list of tasks stored in the database. A task has a priority assigned to it. You can change the priority of a task to reorder the ...
2
votes
5answers
540 views

how to design a stack without using java library or using list [closed]

I have a question how to design a stack without using list or array? This is one question that I want to think about as I want to better understand stack.
7
votes
8answers
15k views

What is the difference between an Array and a Stack?

According to Wikipedia, a stack: is a last in, first out (LIFO) abstract data type and linear data structure. While an array: is a data structure consisting of a collection of elements ...
0
votes
1answer
2k views

Is a PHP array an example of a dynamic data structure?

I did my homework, and it says that dynamic data structures are "data structures that change in size as a program needs it to by allocating and de-allocating memory from the heap". So I was ...
5
votes
2answers
2k views

Why does Python use hash table to implement dict, but not Red-Black Tree? [closed]

Why does Python use hash table to implement dict, but not Red-Black Tree? What is the key? Performance?
2
votes
2answers
416 views

Collection vs data structure vs aggregate

I know three terms that have to do with storing objects or data. I'm not sure I understand the exact differences between the terms. Please confirm if what I'm about to write is accurate. A data ...
10
votes
5answers
6k views

Real world usage of DelayQueue

What would be a real world usage of DelayQueue, what common problem it was designed to solve?
-2
votes
1answer
77 views

How to maintain trade off between number of columns in table vs join operations? [closed]

I have learnt that if there are more columns in table, then get those results using join query. How to decide the max number of columns in table? How feasible is "Join Operation" if too many table ...
0
votes
2answers
557 views

Data structures VS Classes and what happens if they merge? [closed]

Alright so I've learned this: Classes have public methods that perform operations on the class's data and they hide away their implementations. Data structures on the other hand, completely expose ...
1
vote
2answers
1k views

Radix exchange sort implementation?

I need a little help understanding the implementation of radix exchange sort algorithm. Radix exchange (I don't know if it's the exact name in english based literature) is a lot similar to quicksort, ...
6
votes
3answers
1k views

Faster reads, on an infinite grid plane, than using a hash table?

In the past, I've had alot of success just using a .NET Dictionary, with a TKey consisting of the X,Y coordinates merged together. However its read performance, despite being amortized constant time, ...
0
votes
1answer
65 views

Testing the Consumers of Subclassed Data Structures

PHP's SplQueue does not include a clear() or reset() function to wipe data out of the data structure. My application requires that functionality. This leaves two options: A) Create a subclass of ...
1
vote
1answer
233 views

Chained ruleset parsing and evaluation code: recommendations?

So I have to write a filtering system, which may apply preprocessed ruleset to data - and trigger some actions defined in the ruleset while continuing its evaluation. <ruleset name="1"> ...
41
votes
6answers
4k views

How necessary is it to follow defensive programming practices for code that will never be made publicly available?

I'm writing a Java implementation of a card game, so I created a special type of Collection I'm calling a Zone. All modification methods of Java's Collection are unsupported, but there's a method in ...
0
votes
2answers
321 views

Most efficient data structure for implementing inheritance structure without classes

I have a number of types that all relate to each other in terms of them being 'derived' from one another. I'd need a way to do is relationships, which made me initially think of classes, but I ...
3
votes
4answers
408 views

fast n-gram access data structure

TL;DR Is there a data structure that'd quickly let me match words at any point (e.g., 'foo' matches 'foobar' and 'zoofoo'), and, ideally, returns a list of "characters that show up after the needle" ...
4
votes
1answer
235 views

Designing storage service data structure for decoupled models sharing same data

Surely most of you remember the Norton Commander application where similar (sometimes the same) data is displayed in separate decoupled views. I'm building a web application that follows the same ...
0
votes
1answer
92 views

What is the difference between a Splay Tree and an Optimal Binary Search Tree?

Both these trees try to keep the most frequently accessed element at the top. Is there any difference between these two trees?
1
vote
2answers
176 views

Minimize touching the already-working code when a radical change is required

I have a code that highly relies on an Array structure like the following: $array['customer'][$customer_id]['details'][..]; // it goes to about 10 levels deep However, after almost two years ...
3
votes
1answer
358 views

How do I transparently cache data in intermediate stages of processing?

I am working with MATLAB on a model reduction algorithm. It is basically a data processing pipeline. ckt = generate_ckt(ckt_properties); freq = generate_fpoints(fconfig); result = ...
0
votes
1answer
84 views

Method to store some site content data, allowing reusability

(Don't believe this is a "best practice" question as I believe there will be a single better choice). I need to choose a data storage option to store specific site data to allow easy management and ...
1
vote
2answers
318 views

Data retrieval and indexing

I have around 800,000 rows of data stored in the boost shared memory from the database. The data are in the form: Id Color Length Size 1 1 2 ...
0
votes
2answers
258 views

Data structure theory based on graph rewriting [closed]

First of all, I'm looking for a book, publication, project or any kind of information that should probably exceed the limits normally imposed on answers in this kind of forum. I know the rules about ...
4
votes
5answers
503 views

Is my understanding of abstract datatypes correct?

After reading lots of pages on various sites, I came to the conclusion that abstract datatype helps to separate the use of datastructure from its implementation. We can easily map the data into a ...
1
vote
1answer
335 views

Is there already a “Binder” data-structure?

I was thinking of a data structure that I cannot describe better than with the word "book", or more exactly "binder". I was wondering if this had already been implemented in libraries like Boost or ...
1
vote
2answers
589 views

Arrow => in Perl

What does the => mean in Perl? my $CreateArray = [ objectClass => [ "top", "person", "organizationalPerson", "inetOrgPerson" ], cn => "Jane User", uid => "0000001", sn => "User", mail ...
1
vote
1answer
424 views

Handling timeout in network application

How can I handle timeouts in a network application. I'm implementing a provisioning system on a Linux server, the code is huge so I'm going to put the algorithm, it works as like this Read ...