Hello, amironov79, you wrote: >> All these EF, Hibernate - they that, really such useless in industrial (in the sense, heaped up to horror) systems? A> they are functional and convenient, but when understand, what mechanisms (which functions often it is necessary also at themselves in application) there turn, there is a question in such monsters. Me monsters only when they work incorrectly. And so, I the expert in their cultivation A> If to take any program of data handling, it: A> 1. Reads the data (query generator, mapper), A> 2. Changes them (change tracker), A> 3. Saves changed (query generator, mapper, conflict resolver). Interesting - how much well it builds sequence of changes which are rolled on (relational) database. And as it is possible to influence this process. For example - renumbering of documents. Was: 2,3,1. Became: 1,2,3. Column DocNumber unique, but is not primary key. Proceeding from the experience with replication of enough difficult and large database (registration of transactions with real estate of the Lipetsk region, 2000-2008) is is under construction the oriented graph (without cycles) which then in some passes is rolled on basis. I think, too most should be and in ORM. And probably there are methods to be built in processes of formation of this graph and it .