Re: Mark a transaction uncommittable

The following review has been posted through the commitfest application:
make installcheck-world:  tested, passed
Implements feature:       tested, passed
Spec compliant:           not tested
Documentation:            not tested

Hello

It is one of those features that a handful of people would find useful in specific user cases. I think it is a nice to
havefeature that safeguards your production database against unwanted commits when troubleshooting production problems.
Yourpatch applies fine on master and I am able to run a couple tests on it and it seems to do as described. I noticed
thatthe patch has a per-session variable "default_transaction_committable" that could make all transaction committable
oruncommittable on the session even without specifying "begin transaction not committable;" I am wondering if we should
havea configurable default at all as I think it should always defaults to true and unchangable. If an user wants a
uncommittabletransaction, he/she will need to explicitly specify that during "begin". Having another option to change
defaultbehavior for all transactions may be a little unsafe, it is possible someone could purposely change this default
tofalse on a production session that needs transactions to absolutely commit, causing damages there. 
 

thank you
Cary Huang
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Highgo Software Canada
www.highgo.ca