PostgreSQL DBA get locks

gistfile1.sql

with t_wait as                       
(select a.mode,a.locktype,a.database,a.relation,a.page,a.tuple,a.classid,  
a.objid,a.objsubid,a.pid,a.virtualtransaction,a.virtualxid,a,  
transactionid,b.query,b.xact_start,b.query_start,b.usename,b.datname   
  from pg_locks a,pg_stat_activity b where a.pid=b.pid and not a.granted),  
t_run as   
(select a.mode,a.locktype,a.database,a.relation,a.page,a.tuple,  
a.classid,a.objid,a.objsubid,a.pid,a.virtualtransaction,a.virtualxid,  
a,transactionid,b.query,b.xact_start,b.query_start,  
b.usename,b.datname from pg_locks a,pg_stat_activity b where   
a.pid=b.pid and a.granted)   
select r.locktype,r.mode r_mode,r.usename r_user,r.datname r_db,  
r.relation::regclass,r.pid r_pid,  
r.page r_page,r.tuple r_tuple,r.xact_start r_xact_start,  
r.query_start r_query_start,  
now()-r.query_start r_locktime,r.query r_query,w.mode w_mode,  
w.pid w_pid,w.page w_page,  
w.tuple w_tuple,w.xact_start w_xact_start,w.query_start w_query_start,  
now()-w.query_start w_locktime,w.query w_query    
from t_wait w,t_run r where  
  r.locktype is not distinct from w.locktype and  
  r.database is not distinct from w.database and  
  r.relation is not distinct from w.relation and  
  r.page is not distinct from w.page and  
  r.tuple is not distinct from w.tuple and  
  r.classid is not distinct from w.classid and  
  r.objid is not distinct from w.objid and  
  r.objsubid is not distinct from w.objsubid and  
  r.transactionid is not distinct from w.transactionid and  
  r.pid <> w.pid  
  order by   
  ((  case w.mode  
    when 'INVALID' then 0  
    when 'AccessShareLock' then 1  
    when 'RowShareLock' then 2  
    when 'RowExclusiveLock' then 3  
    when 'ShareUpdateExclusiveLock' then 4  
    when 'ShareLock' then 5  
    when 'ShareRowExclusiveLock' then 6  
    when 'ExclusiveLock' then 7  
    when 'AccessExclusiveLock' then 8  
    else 0  
  end  ) +   
  (  case r.mode  
    when 'INVALID' then 0  
    when 'AccessShareLock' then 1  
    when 'RowShareLock' then 2  
    when 'RowExclusiveLock' then 3  
    when 'ShareUpdateExclusiveLock' then 4  
    when 'ShareLock' then 5  
    when 'ShareRowExclusiveLock' then 6  
    when 'ExclusiveLock' then 7  
    when 'AccessExclusiveLock' then 8  
    else 0  
  end  )) desc,r.xact_start;