heapam: Use exclusive lock on old page in CLUSTER To be able to guarantee that we can set the hint bit, acquire an exclusive lock on the old buffer. This is required as a future commit will only allow hint bits to be set with a new lock level, which is acquired as-needed in a non-blocking fashion.
We need the hint bits, set in heapam_relation_copy_for_cluster() -> HeapTupleSatisfiesVacuum(), to be set, as otherwise reform_and_rewrite_tuple() -> rewrite_heap_tuple() will get confused. Specifically, rewrite_heap_tuple() checks for HEAP_XMAX_INVALID in the old tuple to determine whether to check the old-to-new mapping hash table. It'd be better if we somehow could avoid setting hint bits on the old page. A common reason to use VACUUM FULL is very bloated tables - rewriting most of the old table during VACUUM FULL doesn't exactly help. Reviewed-by: Heikki Linnakangas <[email protected]> Reviewed-by: Kirill Reshke <[email protected]> Discussion: https://postgr.es/m/4wggb7purufpto6x35fd2kwhasehnzfdy3zdcu47qryubs2hdz@fa5kannykekr Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/852558b9ec9d54194195a7b7418d57e83a2fda70 Modified Files -------------- src/backend/access/heap/heapam_handler.c | 16 +++++++++++++++- src/backend/access/heap/heapam_visibility.c | 7 +++++++ src/backend/access/heap/rewriteheap.c | 3 +++ 3 files changed, 25 insertions(+), 1 deletion(-)
