On 09/30/2014 03:53 PM, Andres Freund wrote: > On 2014-09-30 18:47:24 -0400, Tom Lane wrote: >> Josh Berkus <j...@agliodbs.com> writes: >>> On 09/30/2014 02:43 PM, Tom Lane wrote: >>>> =?UTF-8?Q?Fabr=C3=ADzio_de_Royes_Mello?= <fabriziome...@gmail.com> writes: >>>>> What's your thoughts about we implement IF NOT EXISTS for CREATE INDEX? >> >>>> It's got the same semantic problems as every other variant of CINE. >> >>> I do think it should be name-based. >> >> Name-based, eh? Don't you recall that in modern practice, people >> generally don't specify names for indexes at all? They've usually >> got system-generated names, which doesn't seem like a very cool thing >> to have scripts depending on. > > Good point. I think it's fair enough to only allow CINE on named > indexes.
On the other hand, the way we form system-generated names is predicable, so I think it would be perfectly OK to include them. Desirable, in fact. For example, if I did this: CREATE INDEX ON tab1 (cola, colb); CREATE INDEX IF NOT EXISTS ON tab1 (cola, colb); I would expect to not end up with two indexes on those two particular columns, and if we don't omit system-generated names, I won't. Not that I'm a fan of omitting the name ... -- Josh Berkus PostgreSQL Experts Inc. http://pgexperts.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
