Hello, everyday I collect a couple of thousands rows of unique data from our systems and I INSERT them into the table. Since I need no duplicate data, I use EXCEPT clause when INSERTing, like this: === INSERT INTO data SELECT * FROM new_collected_data() EXCEPT SELECT * FROM data; === It works exactly as I need, but there is a small issue I am thinking about how to improve. Yes it's performance, what else? :) Since I am INSERTing new_collected_data() in 10000-rows chunks into a table already containing millions of rows, it takes a few minutes (literally), which is something I understand and accept. However, I am wondering whether there is any way how to improve the performance, either via indices, or ALTERing TABLE with UNIQUE constraint or something else I might have completely forgot about. Does anyone have any recommended approach how to speed up queries containing EXCEPT clause? Thanks a lot, Winco -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
