Chao Li <li.evan.c...@gmail.com> 于2025年8月1日周五 14:47写道：
> > If the index points to the newest version of the tuple, how do old > transactions read the old version of the tuple using an index scan for old > transactions? > > Say there is a long transaction x1, it is on-going. > > And transaction x2 started later than x1 started, and x2 created an index. > Should x1 be visible to the new index? > > My understanding is, the old transaction x1 cannot use the new index to > scan for the old version of the tuple. If you read my example, in the > index, the key is the new age value (99), while the old age value is 4, > thus using the old value will not hit the index entry. > Yeah, in your case, the index is non-visible for x1. Your saying is correct. But what if the table already has an index? -- Thanks, Tender Wang
