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I'm not sure if this is true across all ORM technologies. If it is then should this be made clearer in the article as an advantage to ORM? <span style="font-size: smaller;" class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/87.237.64.150|87.237.64.150]] ([[User talk:87.237.64.150|talk]]) 09:34, 12 April 2012 (UTC)</span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->
Just an observation, but how much of an actual real world advantage is the ability to switch RDBMS without re-coding? Every significant (non-dysfunctional) project I have worked on has defined a single RDBMS at the beginning of the project; either by selecting one or having an incumbent that would take more money to migrate from than the total cost of the planned development. So, in an enterprise development environment (as opposed to an Open source project that may want to support MySQL and PostgreSQL and...) all an ORM gives you is a convenient syntactic sugar to instantiate objects. The cost of this sugar is having the mappings to maintain (instead of the hand-coded object loading code) and being abstracted away from the database. The last thing is a huge hidden cost as in my experience, it encourages developers to not learn how to optimize SQL in their RDBMS. For example, here's a blog post [http://zeroturnaround.com/blog/hibernate-jpa-and-xrebel-continued-understanding-eager-lazy-and-join-fetch-queries-with-an-interactive-profiler/] which describes how to improve Hibernate performance. If the developer had hand-coded the SQL they wouldn't have to spend time digging into why Hibernate was hitting the database 24 times instead of once. Also, when you know a particular dialect of SQL e.g. Oracle you learn more efficient ways of writing SQL that takes advantage of features unique to Oracle. Yes that's vendor lock-in, but in reality most companies do not change RDBMS unless they have a really compelling reason because it is so costly for so little business benefit. Just my 5c <span style="font-size: smaller;" class="autosigned">— Preceding [[Wikipedia:Signatures|unsigned]] comment added by [[Special:Contributions/203.161.88.62|203.161.88.62]] ([[User talk:203.161.88.62|talk]]) 05:39, 20 August 2014 (UTC)</span><!-- Template:Unsigned IP --> <!--Autosigned by SineBot-->
== What about Micro OR/Ms? ==
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