On Mon, Oct 28, 2019 at 6:36 PM Vik Fearing <vik.fear...@2ndquadrant.com> wrote:
> 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. > > that allow the same primary key value row to be insert as long as insertion time is different regards Surafel
