Tom Lane wrote:
Alexandre Arruda <alepaes@xxxxxxxxxxxxxxxxxxxx> writes:
But pg_stat_activity joined with pg_locks only give me informations
about the lock itself.
Realy, I want a (possible) simple information: Who is locking me ?
You need a self-join to pg_locks to find the matching lock that is held
(not awaited) by some process, then join that to pg_stat_activity to
find out who that is.
Tom, thanks for explanation !!!
And if someone need, here will go my views (sorry if I made this in the
long and complicated way)... ;)
1) For transaction locks
create or replace view locks_tr_aux as SELECT a.transaction,a.pid as
pid_locked,b.pid as pid_locker,c.usename as user_locked FROM pg_locks a,
pg_locks b, pg_stat_activity c where b.granted=true and a.granted=false
and a.transaction=b.transaction and a.pid=c.procpid;
create or replace view locks_tr as select a.*,c.usename as user_locker
from locks_tr_aux a,pg_stat_activity c where a.pid_locker=c.procpid;
2) For tables locks
create or replace view locks_tb_aux as SELECT a.relation::regclass as
table,a.transaction,a.pid as pid_locked,b.pid as pid_locker,c.usename as
user_locked FROM pg_locks a, pg_locks b, pg_stat_activity c where
b.granted=true and a.granted=false and a.relation=b.relation and
a.pid=c.procpid;
create or replace view locks_tb as select a.*,c.usename as user_locker
from locks_tb_aux a,pg_stat_activity c where a.pid_locker=c.procpid;
3) For transactionid locks
create or replace view locks_trid_aux as SELECT a.transaction,a.pid as
pid_locked,b.pid as pid_locker,c.usename as user_locked FROM pg_locks a,
pg_locks b, pg_stat_activity c where b.granted=true and a.granted=false
and a.transactionid=b.transactionid and a.pid=c.procpid and
a.locktype='transactionid';
create or replace view locks_trid as select a.*,c.usename as user_locker
from trava_trid_aux a,pg_stat_activity c where a.pid_lockedr=c.procpid;
select * from locks_tr;
select * from locks_tb;
select * from locks_trid;
Best Regads,
Alexandre
Aldeia Digital
