Excerpts from Derrick Rice's message of jue jul 22 12:27:31 -0400 2010: > Is it possible for the contents of reference_table to differ from the first > select to the select on the right hand side of the union? (e.g. because > some other transaction committed additional rows).
No. > If it is not possible, why? Is it because a single query always executes > with serializable (effective) isolation? Yes. (Actually: it's because a query is always executed with a single snapshot). > Is it because postgresql > recognizes that the query is repeated and uses a single result set in both > sides of the union? No. > Is this behavior that is part of postgresql intentionally, or a side effect > that I should not rely on? It is intentional and will not be changed. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
