On Sun, Jan 09, 2011 at 12:07:49PM -0600, Kevin Grittner wrote: > There's an issue where we don't seem to have consensus yet, so I > figured I'd bounce it off the list. > > If the SSI patch were to be accepted as is, REPEATABLE READ would > continue to provide the exact same snapshot isolation behavior which > both it and SERIALIZABLE do through 9.0, and SERIALIZABLE would > always use SSI on top of the snapshot isolation to prevent > serialization anomalies. In his review, Jeff argued for a > compatibility GUC which could be changed to provide legacy behavior > for SERIALIZABLE transactions -- if set, SERIALIZABLE would fall > back to working the same as REPEATABLE READ. > > In an off-list exchange with me, David Fetter expressed opposition > to this, as a foot-gun. I'm not sure where anyone else stands on > this. Personally, I don't care a whole lot because it's trivial to > add, so that seems to leave the vote at 1 to 1. Anyone else care to > tip the scales?
For what it's worth, that exchange started with my proposing a separate SNAPSHOT isolation, but since we'll already providing that isolation level and calling it REPEATABLE READ, I figured we didn't need an extra one that did the exact same thing. :) Cheers, David. -- David Fetter <da...@fetter.org> http://fetter.org/ Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter Skype: davidfetter XMPP: david.fet...@gmail.com iCal: webcal://www.tripit.com/feed/ical/people/david74/tripit.ics Remember to vote! Consider donating to Postgres: http://www.postgresql.org/about/donate -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
