On 2013-12-26 21:11:27 -0800, Peter Geoghegan wrote: > I'm generally opposed to making value locks of any stripe be held for > more than an instant (so we should not hold them indefinitely pending > another conflicting xact finishing). It's not just that it's > convenient to my implementation; I also happen to think that it makes > no sense. Should you really lock a value in an earlier unique index > for hours, pending conflicter xact finishing, because you just might > happen to want to insert said value, but probably not?
There are some advantages: For one, it allows you to guarantee forward progress if you do it right, which surely isn't a bad propert to have. For another, it's much more in line with the way normal uniqueness checks works. Possibly the disadvantages outweigh the advantages, but that's a far cry from making no sense. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers