> > > I didn't mean that we'd want to compress it to the absolute minimum > size. I had envisioned that it would be a simple scheme designed only to > eliminate long runs of identical visibility information (perhaps only > the frozen and always visible regions would be compressed). > > The extra level of indirection would be slower, but if we freeze tuples > more aggressively (which would be much cheaper if we didn't have to go > to the heap), there might be a small number of tuples with interesting > visibility information at any particular time. > > > This should be achievable with current proposal of Heikki, but I think it is useful only for tables which won't have more concurrent operations and on databases without any long running queries. So if we have an option to create a visibiliy map ( on the lines of materialized view ), whenever we want for a table, it would help a good number of use cases, i suppose.
Thanks, Gokul.
