pid in pg_locks not present in procpid pg_stat_activity

I have a problem to verify user to lock a object database. The corrspondence pid from pg_loks to pg_stat_activity not found.
pippo=# select * from pg_locks\g
relation | database | transaction | pid | mode | granted
----------+----------+-------------+------+---------------------+---------
1734991 | 16976 | | 500 | AccessExclusiveLock | t
17785 | 16976 | | 500 | AccessExclusiveLock | t
| | 19091 | 500 | ExclusiveLock | t
1735213 | 16976 | | 500 | AccessExclusiveLock | t
18209 | 16976 | | 500 | AccessExclusiveLock | t
1734989 | 16976 | | 500 | AccessExclusiveLock | t
| | 19290 | 1356 | ExclusiveLock | t
1734987 | 16976 | | 500 | AccessExclusiveLock | t
1734988 | 16976 | | 500 | AccessExclusiveLock | t
17
34986 |

16976 | | 500 | AccessExclusiveLock | t
1734990 | 16976 | | 500 | AccessExclusiveLock | t
16757 | 16976 | | 1356 | AccessShareLock | t
(12 rows)
pippo=# select * from pg_stat_activity\g
datid | datname | procpid | usesysid | usename | current_query
-------+---------+---------+----------+---------------+---------------
16976 | gedis30 | 1356 | 100 | Administrator |
Tanks

Bye !!
Frank Lupo (Wolf) !!

/\_ _/\
\ o o /
--ooo-----ooo---

--
Prendi GRATIS l'email universale che... risparmia: http://www.email.it/f

Sponsor:
Solo su Occhialeria.it una vastissima scelta a prezzi insuperabili!
Per te le migliori marche e un incredibile assortimento.
Clicca qui: http://adv2.email.it/cgi-bin/foclick.cgi?mid=880&d=24-1