291 pg_toast_temp schemas?

summary: database has 291 empty pg_toast_temp schemas.
severity: head-scratcher
version: 9.0.7
platform: RHEL6

description:

* medium-large production database (300GB)
* does data collection and analytics
* lately has been having chronic lock-blocking issues
* does many, daily batch jobs which involve the creation of many temp
tables.

Today, while investigating the lock-blocking issues, I noticed that the
db has pg_toast_temp_1 through 291. All of these schema are completely
empty:

breakpad=# select schemaname, relname from pg_stat_all_tables where
schemaname LIKE 'pg_toast_temp_%';
schemaname | relname
------------+---------

... so, apparently we still have an issue with cleaning up pg_toast_temp
schema?

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com