On Thu, Feb 15, 2024 at 10:33 AM Andres Freund <and...@anarazel.de> wrote: > The issue here is that we need to read index leaf pages (synchronously for > now!) to get the tids to do readahead of table data. What you describe is done > for the table data (IMO not a good idea medium term [1]), but the problem at > hand is that once we've done readahead for all the tids on one index page, we > can't do more readahead without looking at the next index leaf page.
Oh, right. > However, if we want to issue table readahead for tids on the neighboring index > leaf page, we'll - as the patch stands - not hold a pin on the "current" index > leaf page. Which makes index prefetching as currently implemented incompatible > with kill_prior_tuple, as that requires the index leaf page pin being held. But I think it probably also breaks MVCC, as Peter was saying. -- Robert Haas EDB: http://www.enterprisedb.com
