Re: How to crash postgres using savepoints

Tom Lane wrote:
> Joseph Shraibman <jks(at)selectacast(dot)net> writes:
>> See example below. At the very least the documentation needs to tell
>> users that savepoints use shared memory, and the cofusing HINT string
>> needs to be changed to something more useful.
>
> Which part of "You may need to increase max_locks_per_transaction" do
> you find confusing? If you actually need tens of thousands of nested
> savepoints then this is accurate advice.

Because there is nothing anywhere that indicates that a savepoint uses a
lock. When I got the message the first time I was very confused and had
nowhere to look to figure out what the real problem was. A more helpful
message would be "You may need to increase max_locks_per_transaction, or
release your savepoints more often"

Why does a savepoint need shared memory anyway, if it is only useful
inside the transaction it was created in?