Re: WIP: System Versioned Temporal Table

On 28/10/2019 13:48, Surafel Temesgen wrote:
>
>
> On Fri, Oct 25, 2019 at 10:45 PM Vik Fearing
> <vik(dot)fearing(at)2ndquadrant(dot)com <mailto:vik(dot)fearing(at)2ndquadrant(dot)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.