Cleaning bloated pg_attribute

[Michal Taborsky <michal(dot)taborsky(at)mall(dot)cz>]

I managed, by extensive usage of temporary tables, to totally bloat 
pg_attribute. It currently has about 40000 pages with just 3000 tuples. 
The question is, how to restore it to it's former beauty? With ordinary 
table I'd just CLUSTER it, but alas! I cannot do that with system 
catalog. I always get:

db=# cluster pg_attribute_relid_attnam_index on pg_attribute;
ERROR:  "pg_attribute" is a system catalog

The only thing I could think of is VACUUM FULL, but from my former 
experience I guess it'll take maybe over an hour, effectively rendering 
the server unusable, because of the exclusive lock. It is a live 24/7 
system, so I'd really prefer something less drastic than dumping and 
reloading the database (though it's still shorter downtime than with the 
vacuum.)

Isn't there a way to somehow go around the above mentioned limitation 
and CLUSTER the table?

Thanks for your ideas.

--
Michal Táborský
CTO, Internet Mall, a.s.

Internet Mall - obchody, které si oblíbíte
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