Hello, Sergey! > I think it's to avoid duplicate errors when adding tuples from STIP to the > main index, > but couldn't we just suppress that error during validation and skip the new > tuple insertion if it already exists?
In some cases, it is not possible: – Some index types (GiST, GIN, BRIN) do not provide an easy way to detect such duplicates. – When we are building a unique index, we cannot simply skip duplicates, because doing so would also skip the rows that should prevent the unique index from being created (unless we add extra logic for B-tree indexes to compare TIDs as well). > The main index may get huge after building, and iterating over it in a single > thread and then sorting tids can be time consuming. My tests indicate that the overhead is minor compared with the time spent scanning the heap and building the index itself. > At least I guess one can skip it when STIP is empty. Yes, that’s a good idea; I’ll add it later. > p.s. I noticed that `stip.c` has a lot of functions that don't follow the > Postgres coding style of return type on separate line. Hmm... I’ll fix that as well. Best regards, Mikhail.
