On 28/10/2019 13:48, Surafel Temesgen wrote: > > > On Fri, Oct 25, 2019 at 10:45 PM Vik Fearing > <vik.fear...@2ndquadrant.com <mailto:vik.fear...@2ndquadrant.com>> wrote: > > > > > I don't understand what you mean by this. > > > > > > > > The primary purpose of adding row end time to primary key is to > allow > > duplicate value to be inserted into a table with keeping > constraint in > > current data but it can be duplicated in history data. Adding row > > start time column to primary key will eliminate this uniqueness for > > current data which is not correct > > > How? The primary/unique keys must always be unique at every point > in time. > > > From user prospect it is acceptable to delete and reinsert a record > with the same key value multiple time which means there will be > multiple record with the same key value in a history data but there is > only one values in current data as a table without system versioning > do .I add row end time column to primary key to allow user supplied > primary key values to be duplicated in history data which is acceptable >
Yes, I understand that. I'm saying you should also add the row start time column.
