On Thu, Feb 05, 2026 at 11:19:46AM -0500, Andres Freund wrote: > It certainly seems better than what we do now. Still feels pretty grotty and > error prone to me that we fill the catalog table and then throw the contents > out.
Before I go any further with this approach, I thought of something else we could do that I believe is worth considering... As of commit 3bcfcd815e, the only reason we are dumping any of pg_largeobject_metadata at all is to avoid an ERROR during COMMENT ON or SECURITY LABEL ON because the call to LargeObjectExists() in get_object_address() returns false. If we bypass that check in binary-upgrade mode, we can skip dumping pg_largeobject_metadata entirely. The attached patch passes our existing tests, and it seems to create the expected binary-upgrade-mode dump files, too. I haven't updated any of the comments yet. -- nathan
>From 1fa1890f6bf98b718118f070226d8b102073e165 Mon Sep 17 00:00:00 2001 From: Nathan Bossart <[email protected]> Date: Thu, 5 Feb 2026 11:26:39 -0600 Subject: [PATCH v2 1/1] fix pg_largeobject_metadata file transfer --- src/backend/catalog/objectaddress.c | 2 +- src/bin/pg_dump/pg_dump.c | 53 +++++++++++++---------------- 2 files changed, 24 insertions(+), 31 deletions(-) diff --git a/src/backend/catalog/objectaddress.c b/src/backend/catalog/objectaddress.c index 02af64b82c6..1762146c09a 100644 --- a/src/backend/catalog/objectaddress.c +++ b/src/backend/catalog/objectaddress.c @@ -1046,7 +1046,7 @@ get_object_address(ObjectType objtype, Node *object, address.classId = LargeObjectRelationId; address.objectId = oidparse(object); address.objectSubId = 0; - if (!LargeObjectExists(address.objectId)) + if (!LargeObjectExists(address.objectId) && !IsBinaryUpgrade) { if (!missing_ok) ereport(ERROR, diff --git a/src/bin/pg_dump/pg_dump.c b/src/bin/pg_dump/pg_dump.c index 2bebefd0ba2..6bcb2f61fe8 100644 --- a/src/bin/pg_dump/pg_dump.c +++ b/src/bin/pg_dump/pg_dump.c @@ -1129,19 +1129,11 @@ main(int argc, char **argv) */ if (dopt.binary_upgrade && fout->remoteVersion >= 120000) { - TableInfo *lo_metadata = findTableByOid(LargeObjectMetadataRelationId); - TableInfo *shdepend = findTableByOid(SharedDependRelationId); + TableInfo *shdepend; - makeTableDataInfo(&dopt, lo_metadata); + shdepend = findTableByOid(SharedDependRelationId); makeTableDataInfo(&dopt, shdepend); - /* - * Save pg_largeobject_metadata's dump ID for use as a dependency for - * pg_shdepend and any large object comments/seclabels. - */ - lo_metadata_dumpId = lo_metadata->dataObj->dobj.dumpId; - addObjectDependency(&shdepend->dataObj->dobj, lo_metadata_dumpId); - /* * Only dump large object shdepend rows for this database. */ @@ -1149,22 +1141,20 @@ main(int argc, char **argv) "AND dbid = (SELECT oid FROM pg_database " " WHERE datname = current_database())"; - /* - * If upgrading from v16 or newer, only dump large objects with - * comments/seclabels. For these upgrades, pg_upgrade can copy/link - * pg_largeobject_metadata's files (which is usually faster) but we - * still need to dump LOs with comments/seclabels here so that the - * subsequent COMMENT and SECURITY LABEL commands work. pg_upgrade - * can't copy/link the files from older versions because aclitem - * (needed by pg_largeobject_metadata.lomacl) changed its storage - * format in v16. - */ - if (fout->remoteVersion >= 160000) - lo_metadata->dataObj->filtercond = "WHERE oid IN " - "(SELECT objoid FROM pg_description " - "WHERE classoid = " CppAsString2(LargeObjectRelationId) " " - "UNION SELECT objoid FROM pg_seclabel " - "WHERE classoid = " CppAsString2(LargeObjectRelationId) ")"; + if (fout->remoteVersion < 160000) + { + TableInfo *lo_metadata; + + lo_metadata = findTableByOid(LargeObjectMetadataRelationId); + makeTableDataInfo(&dopt, lo_metadata); + + /* + * Save pg_largeobject_metadata's dump ID for use as a dependency + * for pg_shdepend and any large object comments/seclabels. + */ + lo_metadata_dumpId = lo_metadata->dataObj->dobj.dumpId; + addObjectDependency(&shdepend->dataObj->dobj, lo_metadata_dumpId); + } } /* @@ -4079,7 +4069,7 @@ getLOs(Archive *fout) * We should've saved pg_largeobject_metadata's dump ID before * this point. */ - Assert(lo_metadata_dumpId); + Assert(lo_metadata_dumpId || fout->remoteVersion >= 160000); loinfo->dobj.dump &= ~(DUMP_COMPONENT_DATA | DUMP_COMPONENT_ACL | DUMP_COMPONENT_DEFINITION); @@ -4088,9 +4078,12 @@ getLOs(Archive *fout) * pg_largeobject_metadata so that any large object * comments/seclables are dumped after it. */ - loinfo->dobj.dependencies = (DumpId *) pg_malloc(sizeof(DumpId)); - loinfo->dobj.dependencies[0] = lo_metadata_dumpId; - loinfo->dobj.nDeps = loinfo->dobj.allocDeps = 1; + if (fout->remoteVersion < 160000) + { + loinfo->dobj.dependencies = (DumpId *) pg_malloc(sizeof(DumpId)); + loinfo->dobj.dependencies[0] = lo_metadata_dumpId; + loinfo->dobj.nDeps = loinfo->dobj.allocDeps = 1; + } } else loinfo->dobj.dump &= ~DUMP_COMPONENT_DATA; -- 2.50.1 (Apple Git-155)
