It is also possible that you will get a foreign key violation exception on the process inserting into table 2, but you will not get database inconsistency.
On Wed, Oct 31, 2012 at 9:33 AM, Albe Laurenz <laurenz.a...@wien.gv.at>wrote: > Yelai, Ramkumar IN BLR STS worte: > > Sent: Wednesday, October 31, 2012 12:40 PM > > To: pgsql-general@postgresql.org > > Subject: [GENERAL] Parallel Insert and Delete operation > > > > Hi All, > > > > Please clarify me the following example. > > > > I have 2 tables > > > > Table1 - ( it has one primary key and few columns ) > > Table2 - ( it has one primary key and few columns. It has one > foreign key, which refers table1 > > primary key ). > > > > I have 2 operations, which are written in pl/pgsql procedure. > > > > Operation1() - Inserts the records to table2 at every hour basis. > > Operation2() - Delete the records from Table 1 and Table2 based on the > primary key. > > > > What if both operations are running at the time for the same primary > key. > > > > what I have to take care to run these two operations perfectly without > creating inconsistency in > > database. > > With the foreign key in place there can be no entry in table2 > that does not have a corresponding entry in table1. > > Concurrency is solved with locks, so one of the concurrent > operations might have to wait until the other one is done. > > That is handled by the database system automatically. > > Yours, > Laurenz Albe > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > -- Moshe Jacobson Nead Werx, Inc. | Senior Systems Engineer 2323 Cumberland Parkway, Suite 201 | Atlanta, GA 30339 mo...@neadwerx.com | www.neadwerx.com
