wyx6...@sina.com wrote: > after shaming , I think i should pick out some my points: > the unique constraints actualy kill concurrency write transaction when > concurrency insert violate the unique constraints , they block each > other , i test this in oracle10g, has the same behavour. I think this > may be reasonable because the uqniue check must be the seriazable check . > for resolve this problem , i do the unique check in application as > possible , but in big concurrency env , this is not good way . >
How can you enforce uniqueness in the application? If you implement it correctly, you need considerably longer than letting it do PostgreSQL. Even if you use some kind of magic, I could not imagine, how you can implement a unique constraint in the application and gaurantee uniqueness while at the same time be faster than the RDBMS. Leo -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
