database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-22 12:22:45 +03:00
Code Activity

Fix bogus collation-version-recording logic.

Browse Source 
recordMultipleDependencies had the wrong scope for its "version"
variable, allowing a version label to leak from the collation entry it
was meant for to subsequent non-collation entries.  This is relatively
hard to trigger because of the OID-descending order that the inputs
will normally arrive in: subsequent non-collation items will tend to
be pinned.  But it can be exhibited easily with a custom collation.

Also, don't special-case the default collation, but instead ignore
pinned-ness of a collation when we've found a version for it.  This
avoids creating useless pg_depend entries, and removes a not-very-
future-proof assumption that C, POSIX, and DEFAULT are the only
pinned collations.

A small problem is that, because the default collation may or may
not have a version, the regression tests can't assume anything about
whether dependency entries will be made for it.  This seems OK though
since it's now handled just the same as other collations, and we have
test cases for both versioned and unversioned collations.

Fixes oversights in commit 257836a75.  Thanks to Julien Rouhaud
for review.

Discussion: https://postgr.es/m/3564817.1618420687@sss.pgh.pa.us
This commit is contained in:
Tom Lane
2021-04-16 12:26:50 -04:00
parent f90c708a04
commit ef387bed87
3 changed files with 10 additions and 24 deletions
Download Patch File Download Diff File Expand all files Collapse all files

16
src/backend/catalog/pg_depend.c
View File

@@ -73,7 +73,6 @@ recordMultipleDependencies(const ObjectAddress *depender,
max_slots,
slot_init_count,
slot_stored_count;
char *version = NULL;
if (nreferenced <= 0)
return; /* nothing to do */
@@ -104,31 +103,22 @@ recordMultipleDependencies(const ObjectAddress *depender,
slot_init_count = 0;
for (i = 0; i < nreferenced; i++, referenced++)
{
bool ignore_systempin = false;
char *version = NULL;
if (record_version)
{
/* For now we only know how to deal with collations. */
if (referenced->classId == CollationRelationId)
{
/* C and POSIX don't need version tracking. */
/* These are unversioned, so don't waste cycles on them. */
if (referenced->objectId == C_COLLATION_OID ||
referenced->objectId == POSIX_COLLATION_OID)
continue;
version = get_collation_version_for_oid(referenced->objectId,
false);
/*
* Default collation is pinned, so we need to force recording
* the dependency to store the version.
*/
if (referenced->objectId == DEFAULT_COLLATION_OID)
ignore_systempin = true;
}
}
else
Assert(!version);
/*
* If the referenced object is pinned by the system, there's no real
@@ -136,7 +126,7 @@ recordMultipleDependencies(const ObjectAddress *depender,
* version. This saves lots of space in pg_depend, so it's worth the
* time taken to check.
*/
if (!ignore_systempin && isObjectPinned(referenced, dependDesc))
if (version == NULL && isObjectPinned(referenced, dependDesc))
continue;
if (slot_init_count < max_slots)