Tom Lane <tgl@sss.pgh.pa.us> wrote:
> I agree that letting it be changed back to read/write after that
> is surprising and unnecessary. Perhaps locking down the setting
> at the time of first grabbing a snapshot would be appropriate.
> IIRC that's how it works for transaction isolation level, and this
> seems like it ought to work the same.
Agreed. I can create a patch today to implement this. The thing
which jumps out first is that assign_transaction_read_only probably
needs to move to variable.c so that it can reference
FirstSnapshotSet as the transaction isolation code does. The
alternative would be to include snapmgr.h in guc.c, which seems less
appealing. Agreed? Other ideas?
-Kevin