monitor SQL activity in db

Hi Gurus,
I'm running PG 9.0.1 and have some issues with some  SQL, I  would like
to know if are  other  system views/tables beside the pg_stat_activity
from where I can get details about a running transactions / SQL at given
time.
Thank you
Isabella

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Isabella A. Ghiurea

Isabella.Ghiurea@nrc-cnrc.gc.ca
Canadian Astronomy Data Centre |http://www.nrc-cnrc.gc.ca/eng/services/hia/data-centre.html
National Research Council of Canada, Herzberg Institute of Astrophysics
5071 West Saanich Road, Victoria BC V9E 2E7, Canada
Phone: 250 363-3446 fax: 250 363-0045