Thread

1. PostgreSQL BugTool Submission

   PostgreSQL Bugs List <pgsql-bugs@postgresql.org> — 2000-08-22T19:36:29Z

   James Aspnes (aspnes@cs.yale.edu) reports a bug with a severity of 2
   The lower the number the more severe it is.
   
   Short Description
   checking foreign keys requires write access
   
   Long Description
   In version 7.0.2, create tables A and B where B has a foreign
   key reference to A.  Grant user X insert access on B but only
   select access on A.  Attempts by X to insert into B will fail
   with an access error on A, even though X is allowed to read A
   (and thus verify that the foreign key constraint is not violated.)[B
   
   Sample Code
   
   
   No file was uploaded with this report
   
   
   

2. Re: PostgreSQL BugTool Submission

   Stephan Szabo <sszabo@megazone23.bigpanda.com> — 2000-08-22T21:14:16Z

   On Tue, 22 Aug 2000 pgsql-bugs@postgresql.org wrote:
   
   > James Aspnes (aspnes@cs.yale.edu) reports a bug with a severity of 2
   > The lower the number the more severe it is.
   > 
   > Short Description
   > checking foreign keys requires write access
   > 
   > Long Description
   > In version 7.0.2, create tables A and B where B has a foreign
   > key reference to A.  Grant user X insert access on B but only
   > select access on A.  Attempts by X to insert into B will fail
   > with an access error on A, even though X is allowed to read A
   > (and thus verify that the foreign key constraint is not violated.)[B
   
   Yes.  This is a known issue due to getting row level locks
   on rows in A with SELECT ... FOR UPDATE which requires update
   permission (and presumably select as well).  For more information,
   check out the -hackers archive over the last couple of months.
   
   The current workaround is somewhat painful, and involves giving 
   update permission and using a trigger to actually prevent unwanted
   changes.