Re: Re: [SQL] Re: pg_dump potential bug -UNIQUE INDEX on PG_SHADOW Dont!! HELP

Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> test=> CREATE UNIQUE INDEX shadow_index ON pg_shadow (usename);
> CREATE
> test=> select * from pg_shadow;
> ERROR: Index 'pg_shadow_sysid_index' does not exist
> test=> \q
> $ psql test
> psql: FATAL 1: Index 'pg_shadow_name_index' does not exist
> $

> Notice the user wanted an index named shadow_index, but the error
> mentioned is pg_shadow_name_index.

What's failing is catcache lookups on pg_shadow. The catcache has table
entries that claim that there are indexes on pg_shadow(usename) and
pg_shadow(usesysid). The system would not work at all, except that
catcache's use of these indexes is defeated by sanity-check code that
notices that relhasindex is FALSE for pg_shadow (line 880 of
catcache.c).

As soon as you create an index on pg_shadow, relhasindex becomes TRUE
and catcache.c starts trying to use these nonexistent indexes for
routine operations like ACL permissions checks. So, nothing works
anymore.

We ought to create those indexes someday ;-)

regards, tom lane