Hi Stéphane, Yes it sounds that extra non primary key column is a straightforward solution.
I believe that the limitation is caused by peculiarities of Ignite SQL. But storage overhead should be calculated in order to measure how critical is it. Also it worth to search Ignite Jira for relevant ticket and create one if none exsts. On a bright side it could be a case that an additional column can have some business meaning in practice. On a bright Sent from my iPhone > On 5 May 2019, at 17:34, Stéphane Thibaud <[email protected]> wrote: > > After some more thought about this: I really think that the constraint of > having one 'non primary key' column is a severe limitation. In combination > with the fact that it is also not possible to create a table without primary > key, it means that a column that wastes space has to be created for a > many-to-many relationship. Am I missing something? > > > Kind regards, > > Stéphane Thibaud > > 2019年5月4日(土) 22:46 Stéphane Thibaud <[email protected]>: >> Hello Apache Ignite users, >> >> I was wondering what would be the best way to model a many to many >> relationship. Since uniqueness constraints do not exist in ignite, I thought >> of setting a primary key constraint on the two columns in my linking table. >> However, Ignite complains that at least one non primary key column needs to >> exist in this case. I could come up maybe come up with a column like >> 'created date', but it seems like a waste of space if not truly necessary. >> Otherwise I might have to accept duplicates and filter on selection. >> What approach would you suggest? >> >> >> Kind regards, >> >> Stéphane Thibaud
