Jinhua Luo schrieb am 18.04.2016 um 16:47: > For trigger, e.g. written in pl/pgsql, each sql command within the > function may see more new data beyond the (entry) snapshot of outer > command.
No it will not see "more data") It runs in the same _transaction_ as the "firing" command and thus sees **exactly** the same data as the triggering statement > So if the "command" term in the read committed isolation level only > refers to outer command (the outer command is the top level command > send by session client), then it's wrong obviously, so it should > clarify that the trigger is an rule exception, in other words, the > commands in trigger should be considered as virtual "outer" commands, > just like you inline the trigger body below the outer command. The visibility of data with regards to isolation levels is all about _transactions_ - **not** statements. Just because you run in auto-commit mode doesn't mean this changes. With autocommit enabled, the first (or outer) statement starts a _transaction_ and that transaction only ends when **that** statement is finished. Any statement that is execute because e.g. a trigger is fired or the statement calls a function that contains several statements is still part of that _transaction_. Thomas -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
