VACUUM ANALYZE

Hi

I have a postgresql database with about 5 tables. On a nightly basis, all
the records in all 5 tables are deleted and repopulated with fresh data.
Some of the tables have between 30 000 and 80 000 records. I have been
looking through the docs to try and work out how best to optimize the
database as I have noticed a definite lag in response as the database grows.

1. I have placed indexes on the columns that are used in searching 
2. when deleting all the records from a table I use TRUNCATE instead of
DELETE 
3. the repopulation occurs via a perl script and at the end of the script I
run VACUUM ANALYZE on the database.

Any other things I should look at? Also, is there a way to check when the
last time VACUUM ANALYZE was run on the db. I am unsure whether the perl
script is running the command successfully.

Thanks
Dave