Tagged Questions

Object-relational mapping is a programming technique that allows applications to work with the data as objects, but store the data in a database as groups of simpler values.

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5
votes
3answers
320 views

Replace relational database with “poor” design in software product with non-relational DB? [closed]

Edit: This question is about how to deal with many issues that arose from a overall system design, which made parts of the system deviate from common standards. For example, managing everything in the ...
0
votes
0answers
35 views

MySql Doctrine ORM DB Design for simple app

I am pretty new to Doctrine and am building a simple app and need some help with some thinking. I have: TableA - call it soccer games TableB - days of the week these games are held on TableC - times ...
0
votes
2answers
33 views

Do I need foreign keys in ORMs?

Object Relational Mapping (take ActiveRecord and Rails, for example) allows a programmer to define relations between models, and callbacks on delete. So my question is: do I still need to define ...
4
votes
1answer
170 views

The future of DBAs with ORM [closed]

I am an aspiring DBA (I'd say in ~3 years I would be ready to apply for a job) and I currently am a programmer. I relayed my future goals to a friend of mine who is part of an Agile SCRUM team in a ...
0
votes
1answer
27 views

Effectively modelling extended classes

I have 3 different types of content for a website, 'Article', 'Video', 'Review'. Each of those three types of content contain common fields and type specific fields. For this, I have created the ...
0
votes
1answer
88 views

Nullable One To Many w/Join Table - Indexing

I have a question regarding database design, I am working with PostgreSQL using Hibernate for ORM, the design I inherited includes the following tables users user_id (pk) user_name user_dob ... ...
1
vote
1answer
136 views

Multi-variance products

My current system houses different variants of Products in different tables; Productgroups Productcolors Productsizes Productmodels Products can reside under 1 Productgroup and can have ...
5
votes
2answers
923 views

What are the advantages of a database design with single table for MtM relationships?

The database that backs our software product has a table design like the following: Positions ID Name Parts 1 One 12345 2 Two 12346 3 Three 12347 Collections ID ...
1
vote
0answers
306 views

Can someone please give me hints on normalizing this database and any other helpful hints

I am using Entity Framework 5 to work with this database but I am getting issues with how tblTalkers and tblChatSessions are being mapped in the entity model when imported into Visual Studio. Please ...
1
vote
1answer
1k views

Java application unable to access Blob stream in Oracle after upgrade to 11g

This issue below might be an application problem, but I cannot seem to rule out a poor database setup, I was hoping to get some insights into potential database issues. I am maintaining a legacy Java ...
6
votes
4answers
369 views

How to troubleshoot orm queries interfering with other applications

Well, it's hypothetical scenario but what I'm trying to understand is the path to go from a post-morten log (say, an SQL Server Profiler trace) to identify the code on a ORM situation. To make it not ...
-1
votes
1answer
997 views

Difference in between HAS MANY and BELONGS TO in Yii framework [closed]

I am new to the Yii Framework. I discovered HAS MANY and BELONGS TO in the documentation, however I am confused about these features. Can someone give some real life examples with a diagram that ...
3
votes
3answers
880 views

How does NHibernate handle execution plan?

I heard from a podcast that there are no ORMs that have a good solution for execution plan reuse. It will lead to increased execution plan cache which affects the performance. How does NHibernate ...
5
votes
3answers
1k views

Is the ADO.NET Entity Framework known for generating poorly performing queries?

This question is inspired by the comment posted to the latest ServerFault blog post: Are you guys still using LINQ to SQL? I know I can use SQL Server Profiler and/or the ToTraceString method to ...
5
votes
3answers
4k views

Why does this Entity Framework query perform so bad in MySQL?

Let me give you a little setup. We have a InnoDB table on MySQL 5.1 with close to 20 million records, no foreign keys, and proper indexes for queries we do. We are using the latest 6.3.5 MySQL ...
13
votes
4answers
748 views

When using an ORM, what are some things to watch out for in your database design

What are some database design gotchas to watch out for when you know the database will be accessed using a ORM? As an example, I'll note the 2100 parameter limit on SqlServer's RPC call. This is a ...