From 8aa9dd74b36757342b6208fbfebb5b35c2d67c53 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 20 Mar 2019 18:06:29 -0400 Subject: [PATCH] Sort the dependent objects before deletion in DROP OWNED BY. This finishes a task we left undone in commit f1ad067fc, by extending the delete-in-descending-OID-order rule to deletions triggered by DROP OWNED BY. We've coped with machine-dependent deletion orders one time too many, and the new issues caused by Peter G's recent nbtree hacking seem like the last straw. Discussion: https://postgr.es/m/E1h6eep-0001Mw-Vd@gemulon.postgresql.org --- src/backend/catalog/dependency.c | 17 +++++++++++++++++ src/backend/catalog/pg_shdepend.c | 8 ++++++++ src/include/catalog/dependency.h | 2 ++ 3 files changed, 27 insertions(+) diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c index 2048d71535..f7acb4103e 100644 --- a/src/backend/catalog/dependency.c +++ b/src/backend/catalog/dependency.c @@ -2610,6 +2610,23 @@ record_object_address_dependencies(const ObjectAddress *depender, behavior); } +/* + * Sort the items in an ObjectAddresses array. + * + * The major sort key is OID-descending, so that newer objects will be listed + * first in most cases. This is primarily useful for ensuring stable outputs + * from regression tests; it's not recommended if the order of the objects is + * determined by user input, such as the order of targets in a DROP command. + */ +void +sort_object_addresses(ObjectAddresses *addrs) +{ + if (addrs->numrefs > 1) + qsort((void *) addrs->refs, addrs->numrefs, + sizeof(ObjectAddress), + object_address_comparator); +} + /* * Clean up when done with an ObjectAddresses array. */ diff --git a/src/backend/catalog/pg_shdepend.c b/src/backend/catalog/pg_shdepend.c index 1619c1c8a7..63a7f4838f 100644 --- a/src/backend/catalog/pg_shdepend.c +++ b/src/backend/catalog/pg_shdepend.c @@ -1266,6 +1266,14 @@ shdepDropOwned(List *roleids, DropBehavior behavior) systable_endscan(scan); } + /* + * For stability of deletion-report ordering, sort the objects into + * approximate reverse creation order before deletion. (This might also + * make the deletion go a bit faster, since there's less chance of having + * to rearrange the objects due to dependencies.) + */ + sort_object_addresses(deleteobjs); + /* the dependency mechanism does the actual work */ performMultipleDeletions(deleteobjs, behavior, 0); diff --git a/src/include/catalog/dependency.h b/src/include/catalog/dependency.h index b235a23f5d..f537f01587 100644 --- a/src/include/catalog/dependency.h +++ b/src/include/catalog/dependency.h @@ -170,6 +170,8 @@ extern void record_object_address_dependencies(const ObjectAddress *depender, ObjectAddresses *referenced, DependencyType behavior); +extern void sort_object_addresses(ObjectAddresses *addrs); + extern void free_object_addresses(ObjectAddresses *addrs); /* in pg_depend.c */ -- 2.40.0