On 7 July 2015 at 15:18, Sawada Masahiko <sawada.m...@gmail.com> wrote:
> > I would also like to see the visibilitymap_test function exposed in SQL, > > so we can write code to examine the map contents for particular ctids. > > By doing that we can then write a formal test that shows the evolution > of tuples from insertion, > > vacuuming and freezing, testing the map has been set correctly at each > stage. > > I guess that needs to be done as an isolationtest so we have an observer > that contrains the xmin in various ways. > > In light of multixact bugs, any code that changes the on-disk tuple > metadata needs formal tests. > > Attached patch adds a few function to contrib/pg_freespacemap to > explore the inside of visibility map, which I used for my test. > I hope it helps for testing this feature. > I don't think pg_freespacemap is the right place. I'd prefer to add that as a single function into core, so we can write formal tests. I would not personally commit this feature without rigorous and easily repeatable verification. -- Simon Riggs http://www.2ndQuadrant.com/ <http://www.2ndquadrant.com/> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
