High-CPU consumption on information_schema (only) query

Hi,

An SQL (with only information_schema related JOINS) when triggered, runs
with max CPU (and never ends - killed after 2 days).
- It runs similarly (very slow) on a replicated server that acts as a
read-only slave.
- Top shows only postgres as hitting max CPU (nothing else). When query
killed, CPU near 0%.
- When the DB is restored on a separate test server (with the exact
postgresql.conf) the same query works fine.
- There is no concurrent usage on the replicated / test server (although
the primary is a Production server and has concurrent users).

Questions:
- If this was a postgres bug or a configuration issue, query on the
restored DB should have been slow too. Is there something very basic I am
missing here?

If someone asks for I could provide SQL + EXPLAIN, but it feels irrelevant
here. I amn't looking for a specific solution but what else should I be
looking for here?

p.s.: All postgres servers are running the v9.3.10

-
robins
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-
robins