Alex Bolenok <quassnoi@xxxxxxxxx> writes: > I get why it's not working (because the statement is not allowed to see the > tuples with its own cmin), but I was wondering if it was worth it at least > to spell it out explicitly in the documentation. What's not explicit about this? The sub-statements in WITH are executed concurrently with each other and with the main query. Therefore, when using data-modifying statements in WITH, the order in which the specified updates actually happen is unpredictable. All the statements are executed with the same snapshot (see Chapter 13), so they cannot “see” one another's effects on the target tables. regards, tom lane