There is a race condition between "GRANT role" and "DROP ROLE",
which allows GRANT to install pg_auth_members entries that refer to
dropped roles. (Commit 6566133c5 prevented that for the grantor
field, but not for the granted or grantee roles.) We'll soon fix
that, at least in HEAD, but pg_dumpall needs to cope with the
situation in case of pre-existing inconsistency. As pg_dumpall
stands, it will emit invalid commands like 'GRANT foo TO ""',
which causes pg_upgrade to fail. Fix it to emit warnings and skip
those GRANTs, instead.
There was some discussion of removing the problem by changing
dumpRoleMembership's query to use JOIN not LEFT JOIN, but that
would result in silently ignoring such entries. It seems better
to produce a warning.
Pre-v16 branches already coped with dangling grantor OIDs by simply
omitting the GRANTED BY clause. I left that behavior as-is, although
it's somewhat inconsistent with the behavior of later branches.
Reported-by: Virender Singla <virender.cse@gmail.com>
Discussion: https://postgr.es/m/CAM6Zo8woa62ZFHtMKox6a4jb8qQ=w87R2L0K8347iE-juQL2EA@mail.gmail.com
Backpatch-through: 13
This directory contains the source code distribution of the PostgreSQL
database management system.
PostgreSQL is an advanced object-relational database management system
that supports an extended subset of the SQL standard, including
transactions, foreign keys, subqueries, triggers, user-defined types
and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
Tom Lane
16eff4261f