Fix another empty nbtree index SSI race. Commit f9b7fc65 fixed a race when predicate-locking completely empty btrees: without a buffer lock held, a matching key could be inserted between _bt_search and the PredicateLockRelation call, so the scan would miss concurrently inserted tuples while the writer wouldn't see the reader's predicate lock. That commit only fixed _bt_first's _bt_search path, though. Scans without useful insertion scan keys return early from _bt_first via _bt_endpoint, which still didn't recheck if the relation was empty.
To fix, add handling to _bt_endpoint that is analogous to the handling added to _bt_search by commit f9b7fc65. Author: Peter Geoghegan <[email protected]> Discussion: https://postgr.es/m/cah2-wzknotn3yxy0igksuavj+sl8erof+kitw+_2v2tjvwu...@mail.gmail.com Backpatch-through: 14 Branch ------ REL_17_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/8434c938598d64f972aceb564104397787a21997 Modified Files -------------- src/backend/access/nbtree/nbtsearch.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
