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

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2
votes
2answers
466 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 ...
0
votes
1answer
218 views

What is a good way to store geographical data for distance calculations

What would be the best way to store data in a database for geographical calculations? Say I have an ItemsForSale table paired to a Users table which holds their geo location. I know I can use latitude ...
-2
votes
1answer
80 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 ...
1
vote
2answers
900 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 ...
0
votes
2answers
604 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 ...
0
votes
2answers
338 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 ...
0
votes
1answer
66 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 ...
3
votes
4answers
439 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" ...
1
vote
1answer
238 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"> ...
0
votes
1answer
96 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
177 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 ...
0
votes
1answer
87 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 ...
4
votes
1answer
240 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 ...
20
votes
3answers
2k views

How do purely functional programming languages deal with fast changing data?

What data structures can you use so you can get O(1) removal and replacement? Or how can you avoid situations when you need said structures?
1
vote
3answers
378 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 ...
1
vote
2answers
333 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 ...
2
votes
1answer
247 views

Graph data structures and journal format for mini-IDE

Background: I am writing a small/partial IDE. Code is internally converted/parsed into a graph data structure (for fast navigation, syntax-check etc). Functionality to undo/redo (also between ...
0
votes
1answer
367 views

Find possible variations of one item out of multiple baskets.

I have three baskets of balls and each of them has 10 balls which have the following numbers: Basket 1: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 Basket 2: 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 ...
2
votes
1answer
185 views

How to organize points on a sphere in bins and navigate between bins?

I'm having trouble coming up with a suitable way to navigate through a set of star coordinates in the Equatorial Coordinate System. My goal is to display those which are within a given range of ...
1
vote
1answer
347 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
1answer
117 views

Implementation/Representation of Symmetries in Chessboards

In a 8X8 chessboard, I was wondering how to implement the symmetry of the board. A lot of positions are just mirrors or rotations of one another (with no pawns or castling capabilities left the ...
1
vote
2answers
214 views

Documenting/defining data structures in Python

What is the preferred way to document the contents of and logic behind dynamically generated data structures in Python? E.g. a dict which contains the mapping of a string to a list of lists of ...
2
votes
2answers
175 views

Replacing static classes with global state to a series of POJOs, beginning to feel like an anti-pattern

I'm trying to refactor some code, and one of the major changes is to remove the (ab)use of static classes to give global state. I've tried to split up some of the 'global state' functionality with ...
5
votes
1answer
150 views

Bloom filters or similar, but with no false positive

To improve some lookups, I am considering the use of Bloom Filters. But in my use-case, the most probable outcome is that the element do exists in the target set. Bloom filters can have false ...
1
vote
0answers
48 views

Compound container for storing output from a parser

Consider a hierarchical structure like this directory [ [item_0;item_1;...;item_n] [item_0;item_1;inner_directory[...];item_m] other_directory [...] ] ...
4
votes
3answers
804 views

Is a tree with nodes that have reference to parent still a tree?

If we make reference to the parent for each node in a tree, do we still have a tree (by definition) anymore? Wikipedia definition is: In computer science, a tree is a widely used abstract data ...
4
votes
5answers
512 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 ...
0
votes
2answers
314 views

Critique the Structure of my Horse Racing Betting Platform

I am creating a program (mostly just for fun) that displays live prices for horse racing markets and the prices that several models predict they should be. I am very interested in the optimal way to ...
0
votes
0answers
43 views

Designing online exam [duplicate]

I need to design an online exam server for an exam like GRE in which question difficulty increases if you answer correctly and decreases if you answer wrong. Questions are multiple choice ...
0
votes
1answer
274 views

Designing online exam

I need to design an online exam server for an exam like GRE in which question difficulty increases if you answer correctly and decreases if you answer wrong. Questions are multiple choice ...
0
votes
1answer
304 views

Is there any practical algorithm / data-structure that can't be done with non-recursive Lambda Calculus augmented with foldl?

In my search for a practical non-turing complete programming language, I've been paying attention to lambda-calculus with disallowed self-application - that is, x x forbidden. After taking that ...
2
votes
3answers
272 views

Why it is `(cons 1 (cons 2 (cons 3 nil)))` and not `(cons 3 (cons 2 (cons 1 nil)))` for [1,2,3]?

Is there any special reason that to construct list in Scheme you use (cons 1 (cons 2 (cons 3 nil))) instead of (cons 3 (cons 2 (cons 1 nil))) ? While the first seems more obvious because it ...
4
votes
2answers
426 views

Is there any particular reason for the use of lists over queues in functional programming languages?

Most functional programming languages such as Scheme and Haskell use lists as their main data structure. Queues are identical to lists, except for the fact appending to the end - not to the begin - ...
1
vote
2answers
193 views

Random access (read/write) in datastructures

Certain datastructures, like Python's Dictionary, are unordered/random read/written. As programming in python is iterative (and programming in general is?), how do these unordered datastructures ...
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, ...
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 ...
1
vote
0answers
232 views

Most suitable data structure for in-memory string -> int conversion for variable length strings

My project involves validating and normalising email addresses in this format [userpart]@[domainpart].[tld] After syntactic validation of the address, [tld] is checked to exist, otherwise the ...
0
votes
2answers
489 views

PHP SplFixedArray How To Deal With billions of indexes?

I've built a flatfile db system that will work like mini-noSQL system and it split db to smaller files, and I did a SplFixedArray wrapper for it with a method for searching usage built on preg_grep. ...
0
votes
1answer
246 views

Which data structure for representing possible navigations between a game's screens?

I am trying to find an appropriate data structure for representing available navigations between a game's screens. Using a linked list, a node can only have one node after it : inappropriate. Using ...
7
votes
4answers
953 views

How do we keep dependent data structures up to date?

Suppose you have a parse tree, an abstract syntax tree, and a control flow graph, each one logically derived from the one before. In principle it is easy to construct each graph given the parse tree, ...
5
votes
1answer
326 views

Can anyone explain to me what problem Core Data solves? [closed]

Core Data seems to add a needless layer of complexity. If you want to save data created natively by the user in an app why not just use an object and then write the data all to SQLite or back to a ...
1
vote
1answer
85 views

Data structure supporting the following operations

I'm looking for a data structure for working with a set of data which is most efficient to do the following : Check whether an item has been categorized or not. (The categorized and uncategorized ...
-2
votes
3answers
180 views

what would be the best data structure for my situation [closed]

I have a list of unique string. I don't want to destroy this string i need it.I only need to find out weather an given string S exist in this unique list.What would be the best data structure for this ...
0
votes
2answers
157 views

How should I structure my database to gain maximum efficiently in this scenario?

I'm developing a PHP script that analyzes the web traffic of my clients websites. By placing a link to a javascript on the clients website (think of Google Analyses), my script harvests information ...
0
votes
1answer
1k views

I need to create an employee schedule/appointments program, but I don't know how to set it up [closed]

I work for a gym. I am the programmer, its just me, nobody else! Gets really frustrating when there's nobody to bounce conceptual ideas off of. I'm getting rid of our archaic paper binder systems for ...
2
votes
2answers
5k views

Is it wise to store a big lump of json on a database row

I have this project which stores product details from amazon into the database. Just to give you an idea on how big it is: [{"title":"Genetic Engineering (Opposing ...
0
votes
4answers
139 views

Data Structure for Small Number of Agents in a Relatively Big 2D World

I'm working on a project where we will implement a kind of world simulation where there is a square 2D world. Agents live on this world and make decisions like moving or replicating themselves based ...
0
votes
1answer
378 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 ...
3
votes
2answers
152 views

Reconstructing a tree from depth information

I have a data structure that describes a tree. Nodes are ordered, with "depth" information, and knowing the order and the depth the tree can be reconstructed. I'm not entirely sure how to describe it ...
3
votes
1answer
1k views

Implementing basic data structures in programming interviews [closed]

I have been preparing to do my first technical interview in a month, and I have a question about implementing common data structures like stacks or linked lists. I plan to do the interview in either ...