<david.sahagian@xxxxxxx> writes: > In postgresql.org/docs/9.1/static/transaction-iso.html I read > 13.2.1. Read Committed Isolation Level > . . . two successive SELECT commands can see different data, even though they are within a single transaction . . . > Please consider this code being executed by postgres: > = = = = = = = = = = > select some_int from tableX > union all > select another_int from tableY > ; > = = = = = = = = = = > Are these two select statements considered "successive" when isolation == Read Committed ? No, the UNION is a single command. The fact that the word "SELECT" occurs twice within it is a SQL syntactic artifact --- it doesn't convert it into two commands. regards, tom lane -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
