You forgot to CC the list. Also, top-posting is generally not appreciated here.
> On Thu, Oct 11, 2018 at 8:26 PM Alban Hertroys <haram...@gmail.com> wrote: > On Thu, 11 Oct 2018 at 16:38, Abhishek Tripathi > <postforabhis...@gmail.com> wrote: > > Actually I have acquired a "Select for Update" on a table whose id is > > refrence as a foreign key on another table So I want those table won't > > update until there is lock. Is it possible? Becuase postgres is acquiring > > lock but AccessShare Lock which allow to write on those table How I > > restrict this. > > For what purpose do you want that? What is inadequate about the lock > that Postgres acquires? > > Table locks are very rarely what you want, as it blocks all concurrent > access to the entire table, while that is only necessary for a few > rarely used corner cases; a foreign key update is not among those. > On Fri, Oct 12, 2018 at 10:33 AM Abhishek Tripathi > <postforabhis...@gmail.com> wrote: > Thank you for your response. > > I am explaining my situation there is table A on which I have taken a row > lock and the primary key of table A is related with table B as a foreign key > so automatically I can not insert new row with that foreign key now the > primary key of table B is used as foreign key in table C and insertion can be > done on table C. I just want to lock table C also No insertion can be done on > table C related to table B primary key. > > On 12 Oct 2018, at 8:08, Abhishek Tripathi <postforabhis...@gmail.com> wrote: > > My bad sorry actually there is updation- > > there is table A on which I have taken a row lock and the primary key of > table A is related with table B as a foreign key so automatically I can not > insert new row with that foreign key on table B that is fine now table C > any insertion can be done on table C. I just want to lock table C also No > insertion can be done on table C becuse table C primary key is related to > table B as a foreign key of B. So your tables (simplified) are something like this?: create table A (id primary key) create table B (id primary key, a_id references A (id)) create table C (id primary key, b_id references B (id)) And you insert a new value for b_id in C? That's not possible, unless that value exists in table B, which in turn can't exist unless it's a_id exists in table A. That's how foreign key constraints are designed, you don't need to do manual locking for that to work. Alban Hertroys -- If you can't see the forest for the trees, cut the trees and you'll find there is no forest.
