bbc1376b39
Prior to this commit, we only consider each tuple or line pointer on the page in isolation, but now we can do some validation of a line pointer against its successor. For example, a redirect line pointer shouldn't point to another redirect line pointer, and if a tuple is HOT-updated, the result should be a heap-only tuple. Himanshu Upadhyaya and Robert Haas, reviewed by Aleksander Alekseev, Andres Freund, and Peter Geoghegan.