Tom Lane <t...@sss.pgh.pa.us> writes: > Andy Fan <zhihuifan1...@163.com> writes: >> Tom Lane <t...@sss.pgh.pa.us> writes: >>> Many years ago, we committed a patch to do exactly that. We had >>> to back it out again because it broke too many real-world scenarios. >>> I'm too lazy to search the archives for you, but you might be able >>> to find the commit and revert by searching the git history. > >> Commit id is 532994299e2, thank you Tom! > > links in commit messages till some years after that.
Links in commit messages is a really great change. I have found more details at [1], the issue can be summaried as IIUC: The current strategy is below: t1: snapshot1 parser&planner t2: snapshot2 executor. which makes the committed tuple between (t1, t2] are visible to user, but if we share the same snapshot, the committed tuple would not be visible to user, Chaning it would be a behavior change. [1] https://www.postgresql.org/message-id/5075D8DF.6050500%40fuzzy.cz -- Best Regards Andy Fan
