In computer science, persistence refers to the characteristic of state that outlives the process that created it. From Wikipedia: http://en.wikipedia.org/wiki/Persistence_%28computer_science%29

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Saving tabular, spreadsheet-like data in a relational database?

I'm hoping this question isn't too broad or too prone to opinionated answers, since I could really use some pointers. I'm trying to come up with a way to persist tabular, spreadsheet-like1, data in a ...
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1answer
98 views

Persistence Strategies - Filling a cache strategy

Let's say I have an interface IDataAccessObject<TSource> with CRUD methods to access a data source. I have an implementation StrategyDataAccessObject<TSource>, which uses an strategy ...
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1answer
155 views

Enterprise Architecture: Where to put persistence/dbContext management? [closed]

I'm working on architecting a somewhat enterprise-level solution and have a question about how to best handle the persistence details. My overall setup is that there's a core set of business ...
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2answers
207 views

Persistence models for Event Sourcing

I am intrigued by the Event Sourcing pattern but am struggling to design an event sourcing model and put it in concrete form. First off, I want to make sure that I understand the main use cases of ...
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277 views

What data type should Gateway return in Repository Pattern to eliminate refactoring when switching persistence mechanisms?

Following this description of the Repository Pattern, we have three main concerns that need their own classes: The "Repository," which takes and returns Domain Models. The "Gateway," which takes ...
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57 views

Persisting and manipulating JS ArrayBuffer data on the server

My node.js app has to deal with (sometimes large; a few MB) tables of numerical data. I'm about to use JavaScript's native binary objects for this purpose (i.e. ArrayBuffer and friends), because ...
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1answer
150 views

iOS Best practice for handling model objects

There are different levels I'm asking this question at. Case 1: Let's think about the typical drill-down design. Say a table view controller has an array of custom objects, and tapping a cell will ...
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72 views

What are some common patterns for managing a polyglot persistence layer?

I am pretty interested in the idea of using multiple datastores to support a single application and understand the benefits in theory but would like to know a little more about how things are done in ...
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1answer
158 views

DDD – duplicity between Aggregates – should I use one table?

I understand that there exists duplicity of data between Bounded Contexts. The thing is that I'm not really sure about duplicity of data between Aggregate roots. Example: I have product in Product ...
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1answer
136 views

Rich client persistence without a database

We have a pretty sizable .NET rich client app that currently uses nHibernate and Firebird embedded for persistence. Due to the nature of the app, we need to load the entire database into memory when ...
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2answers
165 views

Is there a detriment to using SQLite over a pList for persistence?

I'm making a fairly simple application and I've got a settings menu that stores times and some boolean values. I have the application storing and retrieving data already but I started to wonder if ...
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2answers
177 views

DDD using an ORM and a Active Directory Server for Persistence

With Domain Driven Design one would model out the domain. One would then use an ORM of some sort to take care of the persistence. Say you have a Product entity which has a Name, SKU and an Owner. This ...
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Strategies for maintaining backwards compatibility when persisting objects to XML [duplicate]

I am using XStream to persist Java objects to files. This works fine and so far I have had no problems. However, in the course of development, the objects have changed. Some new properties have been ...
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1answer
49 views

Do my “dal” and “fileHandler” interfaces overlap?

I want my program to: read some input lines from CSV file write the output lines to plain string file read some input from the same file in (2) and compare it to some calculated data I want to ...
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1answer
161 views

Persist data downloaded by Celery workers

I'm working in a tool that downloads tweets from Twitter to process them later. For this purpose I'm using Celery with RabbitMQ, sending task with the keywords that must be tracked by the workers. My ...
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1answer
272 views

Creating/updating entity save strategy

Please note: although I'm talking about Java in this question, what I'm asking about here should really be language-agnostic. I am dabbling in OR/M for the first time, and have cooked up the ...
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220 views

How do you keep your motivation and enthusiasm for a never ending project? [closed]

At the beginning of a project I tend to finish tasks quickly. However, after a while I start getting bored doing the same thing over and over again. It feels like I am stagnant. How do you keep ...
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1answer
117 views

What programmable system can provide persistent scheduling? [closed]

I want to write an application that creates scheduled events at specific times. When the delay elapses the event notifies the application. The scheduled events must not be stored in the application's ...
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2answers
232 views

Decimal vs. Integer; Given a fixed range of values, which is preferable for accurate computation?

After getting into a "heated discussion" with someone, I figured I'd ask this question for the sake of posterity. I'm willing to be corrected if my assumption is incorrect but I'd like to hear a ...
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2answers
73 views

How to collect industry usage of data persistence technologies? [closed]

In our organization, we are using various data access/persistence technologies in different projects. The ones used till now are Hibernate, JPA, Spring Data JPA, JDBC, Spring JDBC, MyBatis, and ...
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195 views

Structural pattern for an unconventional use of a database

I'm writing a game client as a personal project and using using it as a vehicle to learn about Java database access, specifically Neo4j, and possibly Spring Data Neo4j if I decide it's appropriate. ...
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1answer
236 views

Should my internal MVC/MVVM application use Web Services for Persistence?

Just talking about internal applications or intranet web apps... At some companies I've seen their business-logic piece (Model in MVC/VM in MVVM) on one (or both) sides of a Web Service. And on the ...
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1answer
107 views

Which approach would be better for persisting these overridable configuration keys and values? A simple key-value store, or a graph database?

I'm creating a system where there are config keys and values. So for example: config.key = 10 Is an example of a configuration key and a value. These keys can also have overrides based on ...
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2answers
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What's a good way to make sure that locally serialized data can be deserialized in newer code?

Context: I'm working on an HTML 5 game without persisted state. Every time you refresh the page, you start at the beginning. People are requesting that they can start where they left off if they ...
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2answers
579 views

Can a version of Python's shelve module that knows when its entries have been modified be written in any programming language?

shelve is a Python module that makes it easy to persist a Python dictionary to disk (under the right conditions). The documentation for shelve gives this example to demonstrate one of the pitfalls of ...
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1answer
259 views

Manage the persistence of entities on iOS in several places: CoreData on the device, iCloud and on a REST API

For the needs of a project, I would persist the datas contained in Core Data in several places depending on the state of the user. If the user is logged to my API -> Persist the datas on my API. ...
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751 views

What are the bad points of using Core Data for iOS like an ORM

I just starting to use Core Data for my iOS app and I am thinking about how use Core Data for my needs. What are the features of my app: The user look for products proposed from a catalog. The user ...
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1answer
117 views

Persist AJAX values [closed]

I have a simulator that pulls data from a DB - calculates and return JSON result to an ajax call that renders a table for the results. The calculation procedure are as follow: grab X number of data ...
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1answer
93 views

Persisting type in Java - should I be using flags?

Is there some specific piece of advice around persist values that indicate type? Specifically I want to know if I should persist a flag/state indicating the type in persistence or not. I get the ...
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1answer
208 views

Persistence frameworks and common sense

I have studied some persistence frameworks mainly Hibernate, DORM, TMS Aurelius and I'm wondering. In a model of type: TOrderFiscal < > ----- > Items < > -------- > TOrderItem ...
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368 views

How do I make a domain model that doesn't violate OOP?

My game reads a number of JSON files, deserializes them, and hands the resulting objects off to the classes that need them. These deserialized objects, which can be thought of as the domain model, are ...
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2answers
2k views

DDD and the persistence of value objects; must we denormalize?

I've been reading up a lot on Domain-Driven Development, and I came to the question of how to preserve lack of distinct identity with value objects (VOs). While in the DDD world, this is a requirement ...
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What's the easiest (quickest) way to share one dataset in my app with someone else

I have some javascript that creates a canvas image that I want users to be able to share. I simply need to save the image somehow. Nothing else. I've been contemplating using bits and pieces of ruby ...
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Can I share ~1k of dynamically updated data between HTML5/JS pages using only apache2?

I have an HTML5/Javascript web site. There is a form which updates JSON data. There are other pages which I would like to load that JSON data dynamically. I know how to do this via Tomcat/JSP but I'd ...
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1answer
421 views

How can I implement a modular “save” function for a game?

I have to implement a method to save my game in such a way that I can change the storage medium with the change of only a single variable. Ideally I'd use an interface to designate the required ...
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2k views

Best Practices for serializing/persisting String Object Dictionary entities

I'm noticing a trend towards using a dictionary of string to object (or sometimes string to string), instead of strongly typed objects. For example, the new Katana project makes heavy use of ...
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447 views

Workflow versioning

I believe I have a fundamental misunderstanding when it comes to workflow engines which I would appreciate if you could help me sort out. I'm not sure if my misunderstanding is specific to the ...
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What is a Ruby on Rails way to save images?

I develop on iOS, and I'm switching from a PHP backend to Ruby on Rails. The interchange format is JSON. A quick Google search for 'save images in Rails' has nearly every result talking about saving ...
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2answers
1k views

Does 'consider returning Null Object' apply to a DAO read method?

I was looking for an answer to the question of what a DAO should return when a search ends up to be for an entity that does not exist. There are some generic previous questions related to returning ...
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210 views

The best approach to building a mobile service that's also available when the connection drops?

Hopefully this question will be a good suit for P.SE since it is a whiteboard-level 'how can this be done' conceptual question. I'm trying to build a product that needs to be available to someone on ...
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495 views

Is storing types in the database an anti pattern?

A little background on where this question is coming from. In my current .NET application I'm working on some features related to archiving a certain type of business entity called a "Project". ...
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4answers
324 views

Senior team members want to move query-relevant persistent data from DB to cache. Does this make sense?

I am a young engineer recently employed at a small company that sells products to the general public. We use Ruby On Rails and MySQL. Our database has a lot of customer data, but a great deal more of ...
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In agile development, should I try persistence in flat file before database?

Somebody explained to me that since in agile development, policy and the application logic should be more important than details such as persistence method, persistence decision should be taken at the ...
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How do I design a DAL when I have to deal with relationships?

Say I'm developing a bug tracker, where a ticket belongs to at most one milestone, and a milestone can have many tickets. When a milestone is deleted (from the database), all tickets associated with ...
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2answers
1k views

Patterns for a tree of persistent data with multiple storage options?

I have a real-world problem which I'll try to abstract into an illustrative example. So imagine I have data objects in a tree, where parent objects can access children, and children can access ...
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1k views

Persisting natural language processing parsed data

I've recently started experimenting with natural language processing (NLP) using Stanford's CoreNLP, and I'm wondering what are some of the standard ways to store NLP parsed data for something like a ...
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1answer
745 views

Sample domain model for online store

We are a group of 4 software development students currently studying at the Cape Peninsula University of Technology. Currently, we are tasked with developing a web application that functions as a ...
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172 views

Separating validation from persistence in models?

Models in an MVC application gets kind of hard to test when validation of data and persistence of data is baked together in the model. I would like to test those separately to prevent doing ...
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2k views

Caching factory design

I have a factory class XFactory that creates objects of class X. Instances of X are very large, so the main purpose of the factory is to cache them, as transparently to the client code as possible. ...
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909 views

Clojure state and persistence

I'm learning Clojure to see if it's something I can leverage at my current job, and more importantly, how I can convince my bosses that Clojure has a 'killer feature' over java that makes it worth the ...