"Christopher Kings-Lynne" <chriskl@familyhealth.com.au> writes:
> Just saw these:
> #default_transaction_isolation = 'read committed'
> #default_transaction_read_only = false
> Does the second option control the new read only transaction mode?
Yes.
> I thought 'read only' was just a new level of transaction isolation (ie. one
> of the 4 sql standard ones), so why does it need its own GUC var?
No, it's orthogonal to isolation. A read-only transaction could
sensibly want either READ COMMITTED or SERIALIZABLE behavior, depending
on whether it wants to see the effects of commits while it's in progress.
regards, tom lane