Restore vacuum_delay_point() in GIN posting-tree leaf vacuum Commit fd83c83d094 turned the recursive posting-tree cleanup in ginVacuumPostingTreeLeaves() into an iterative sweep that follows the tree's leaf pages via their rightlinks. The recursive version called vacuum_delay_point() while processing the tree, but that call was removed and never re-added to the new loop. As that commit only set out to fix a deadlock, the removal appears to have been unintentional.
Consequently the leaf-page sweep of a single posting tree runs with no vacuum_delay_point(), and therefore no CHECK_FOR_INTERRUPTS(). A posting tree stores all the TIDs for one indexed key, so for a frequently occurring key it can span a large number of leaf pages. While such a tree is being vacuumed the operation ignores vacuum_cost_delay and does not respond to query cancellation or statement_timeout; an autovacuum worker likewise cannot be interrupted mid-sweep when another backend requests a conflicting lock. Restore the call, placed after the current page has been unlocked and released so that no buffer content lock is held across a potential delay (cf. 21c27af65fb). The sibling loops in ginbulkdelete() and ginvacuumcleanup() already call vacuum_delay_point() once per page. Author: Paul Kim <[email protected]> Co-authored-by: Alexander Korotkov <[email protected]> Reviewed-by: Michael Paquier <[email protected]> Reviewed-by: Andrey Borodin <[email protected]> Reviewed-by: solai v <[email protected]> Discussion: https://postgr.es/m/178447127453.110.12276981925360691905%40mail.gmail.com Backpatch-through: 14 Branch ------ REL_17_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/ba5e4632959027d34ec0254e1597315c3fea4c1e Modified Files -------------- src/backend/access/gin/ginvacuum.c | 7 +++++++ 1 file changed, 7 insertions(+)
