Achilleas Mantzios - cloud <a.mantzios@xxxxxxxxxxxxxxxxxxxx> writes:As you noticed the last trigger is a CONSTRAINT DEFERRABLE trigger. This function mariner_update_availability_date is supposed to be run by a user : cbt_results_import strippedof any privileges to the rest of the system. Here is what we get : when we SET the constraint of the last trigger to IMMEDIATE, the function runs on behalf of its owner (postgres) who has all needed privileges (as superuser) to run the update on mariner table and also run the triggers . However, when we run with this CONSTRAINT as DEFERRED then it seems to NOT run the last deferrable trigger as postgres.AFAIR the trigger mechanisms do not change the execution environment. If they did, then for example a trigger that stuffs CURRENT_USER into a last_updated_by column would not give the desired results. I'd suggest marking the problem trigger function as SECURITY DEFINER if you want it to run as its owner.
Thank you Tom. With a little bit of debugging is obvious that
the last deferred trigger function runs outside the security
environment of the top SECURITY DEFINER function (naturally),
however current_user seems to be on par with the security definer
owner,
cbt_results_import@[local]/dynacom=>
begin ;
BEGIN
cbt_results_import@[local]/dynacom=*> SET CONSTRAINTS
zzzmariner_dmq_tg IMMEDIATE;
SET CONSTRAINTS
cbt_results_import@[local]/dynacom=*> select
mariner_update_availability_date(13916, '2020-02-28');
NOTICE: manage past : the current_user is postgres,
session_user is cbt_results_import, system_user id
md5:cbt_results_import
NOTICE: manage past : the current_user is postgres,
session_user is cbt_results_import, system_user id
md5:cbt_results_import
mariner_update_availability_date
----------------------------------
(1 row)
cbt_results_import@[local]/dynacom=*> commit ;
COMMIT
cbt_results_import@[local]/dynacom=> begin ;
BEGIN
cbt_results_import@[local]/dynacom=*> SET CONSTRAINTS
zzzmariner_dmq_tg DEFERRED;
SET CONSTRAINTS
cbt_results_import@[local]/dynacom=*> select
mariner_update_availability_date(13916, '2020-02-28');
NOTICE: manage past : the current_user is postgres,
session_user is cbt_results_import, system_user id
md5:cbt_results_import
mariner_update_availability_date
----------------------------------
(1 row)
cbt_results_import@[local]/dynacom=*> commit ;
NOTICE: manage past : the current_user is cbt_results_import,
session_user is cbt_results_import, system_user id
md5:cbt_results_import
ERROR: permission denied for table export_dmq
CONTEXT: SQL statement "DELETE FROM export_dmq where id=($1).id
and op='U' and tbl='mariner'"
PL/pgSQL function export_dmq() line 18 at EXECUTE
Thank you and sorry for missing something so obvious.
regards, tom lane
