Обсуждение: strange exclusive lock in relation --- ideas
hello all, i came with a strange finding the other day and i would appreciate any ideas on the matter (if any). while checking on the locks of the server i found a tuple indicating that a prepared transaction had requested an exclusive lock on a relation. in general, i am aware of the situations where an exclusive lock is requested (alter table, drop, create index, vacuum full ...) but i would like to know if there are any other cases when an exclusive lock request could be issued. i have ran many tests since then but didnt manage to recreate the lock. i used various combinations of concurrent transactions of inserts,update,deletes using foreign keys and other constraints but with no use. so, do you have in mind any other situation (beside the obvious ones mentioned before) when such a lock can be requested? thx in advance -- View this message in context: http://postgresql.1045698.n5.nabble.com/strange-exclusive-lock-in-relation-ideas-tp4730583p4730583.html Sent from the PostgreSQL - general mailing list archive at Nabble.com.
On Wed, Aug 24, 2011 at 9:11 AM, MirrorX <mirrorx@gmail.com> wrote: > hello all, > > i came with a strange finding the other day and i would appreciate any ideas > on the matter (if any). while checking on the locks of the server i found a > tuple indicating that a prepared transaction had requested an exclusive lock > on a relation. in general, i am aware of the situations where an exclusive > lock is requested (alter table, drop, create index, vacuum full ...) but i > would like to know if there are any other cases when an exclusive lock > request could be issued. i have ran many tests since then but didnt manage > to recreate the lock. i used various combinations of concurrent transactions > of inserts,update,deletes using foreign keys and other constraints but with > no use. so, do you have in mind any other situation (beside the obvious ones > mentioned before) when such a lock can be requested? thx in advance a couple more 'obvious' ones: LOCK CLUSTER TRUNCATE REINDEX hm, can't think of anything else off top of head... merlin