Excerpts from Robert Haas's message of mar ago 16 09:59:04 -0400 2011: > On Mon, Aug 15, 2011 at 6:46 PM, Joachim Wieland <j...@mcknight.de> wrote:
> > Also see what Robert wrote about proxies in between that keep track > > of the transaction state. Consider they see a BEGIN query that > > fails. How would they know if the session is now in an aborted > > transaction or not in a transaction at all? > > I think the point here is that we should be consistent. Currently, > you can make BEGIN fail by doing it on the standby, and asking for > READ WRITE mode: > > rhaas=# begin transaction read write; > ERROR: cannot set transaction read-write mode during recovery > > After doing that, you are NOT in a transaction context: > > rhaas=# select 1; > ?column? > ---------- > 1 > (1 row) > > So whatever this does should be consistent with that, at least IMHO. I think we argued about a very similar problem years ago and the outcome was that you should be left in an aborted transaction block; otherwise running a dumb SQL script (which has no way to "abort if it fails") could wreak serious havoc (?). I think this failure to behave in that fashion on the standby is something to be fixed, not imitated. What this says is that a driver or app seeing BEGIN fail should issue ROLLBACK before going further -- which seems the intuitive way to behave to me. No? -- Álvaro Herrera <alvhe...@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
