> > I am not familiar with the python library, but that looks correct
> > to me. You can always test it by adding a sleep between your two
> > queries and modifying the database from a console connection
> > during the sleep.
>
> > Note that I'm assuming your 5 queries are all read-only selects.
> > If you're modifying data during your queries, and another
> > concurrent database connection modifies the same data during your
> > transaction, the later modifications will fail under serializable
> > isolation.
>
> Which one will fail? the second query or the serializable
> transaction.
>
> My understanding was that the serializable transaction will fail.
>
Yes, serializable transactions fail if they attempt to modify data
which has changed since the beginning of the transaction. If the
OP's ajax call kicks off 5 queries in a serializable transaction,
there is the potential for failure if two ajax calls initiate
simultaneous serializable transactions modifying data.
