* Gnanakumar: >> Just create a unique index on EMAIL column and handle error if it comes > > Thanks for your suggestion. Of course, I do understand that this could be > enforced/imposed at the database-level at any time. But I'm trying to find > out whether this could be solved at the application layer itself. Any > thoughts/ideas? If you use serializable transactions in PostgreSQL 9.1, you can implement such constraints in the application without additional locking. However, with concurrent writes and without an index, the rate of detected serialization violations and resulting transactions aborts will be high. -- Florian Weimer <fweimer@xxxxxx> BFK edv-consulting GmbH http://www.bfk.de/ Kriegsstraße 100 tel: +49-721-96201-1 D-76133 Karlsruhe fax: +49-721-96201-99 -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
