Tom Lane wrote:
Alexandre Arruda <[EMAIL PROTECTED]> 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

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
      choose an index scan if your joining column's datatypes do not
      match

Reply via email to