This can lead to deadlocks during parallel restore. Test case:
create table bar (a int primary key, b int);
create table baz (z int, a int references bar);
create view foo as select a, b, sum(1) from bar group by a union all
select z, a, 0 from baz;
I dumped this with: pg_dump -Fc -s -f test.dmp
Then: while (dropdb rhaas; createdb; pg_restore -O -d rhaas -j3
test.dmp); do true; done
This quickly fails for me with:
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 2155; 2606 47822 FK
CONSTRAINT baz_a_fkey rhaas
pg_restore: [archiver (db)] could not execute query: ERROR: deadlock detected
DETAIL: Process 81791 waits for AccessExclusiveLock on relation 47862
of database 47861; blocked by process 81789.
Process 81789 waits for AccessShareLock on relation 47865 of database
47861; blocked by process 81791.
HINT: See server log for query details.
Command was: ALTER TABLE ONLY baz
ADD CONSTRAINT baz_a_fkey FOREIGN KEY (a) REFERENCES bar(a);
WARNING: errors ignored on restore: 2
The attached patch seems to fix it for me.
Comments?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
diff --git a/src/bin/pg_dump/pg_backup_archiver.c b/src/bin/pg_dump/pg_backup_archiver.c
index ded9135..0393153 100644
--- a/src/bin/pg_dump/pg_backup_archiver.c
+++ b/src/bin/pg_dump/pg_backup_archiver.c
@@ -4140,11 +4140,10 @@ identify_locking_dependencies(ArchiveHandle *AH, TocEntry *te)
return;
/*
- * We assume the item requires exclusive lock on each TABLE DATA item
- * listed among its dependencies. (This was originally a dependency on
- * the TABLE, but fix_dependencies repointed it to the data item. Note
- * that all the entry types we are interested in here are POST_DATA, so
- * they will all have been changed this way.)
+ * We assume the item requires exclusive lock on each TABLE or TABLE DATA
+ * item listed among its dependencies. (fix_dependencies may have
+ * repointed TABLE dependencies at TABLE DATA items, but not in a
+ * schema-only dump.)
*/
lockids = (DumpId *) pg_malloc(te->nDeps * sizeof(DumpId));
nlockids = 0;
@@ -4153,7 +4152,8 @@ identify_locking_dependencies(ArchiveHandle *AH, TocEntry *te)
DumpId depid = te->dependencies[i];
if (depid <= AH->maxDumpId && AH->tocsByDumpId[depid] != NULL &&
- strcmp(AH->tocsByDumpId[depid]->desc, "TABLE DATA") == 0)
+ ((strcmp(AH->tocsByDumpId[depid]->desc, "TABLE DATA") == 0) ||
+ strcmp(AH->tocsByDumpId[depid]->desc, "TABLE") == 0))
lockids[nlockids++] = depid;
}
--
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