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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4
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1answer
90 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
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1answer
24 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
49 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
102 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
629 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
239 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
853 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
338 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
678 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
760 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
931 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
3k 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
668 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 ...