| From: | Kevin Grittner <kgrittn(at)ymail(dot)com> |
|---|---|
| To: | Andres Freund <andres(at)2ndquadrant(dot)com> |
| Cc: | Peter Geoghegan <pg(at)heroku(dot)com>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>, Pg Hackers <pgsql-hackers(at)postgresql(dot)org>, Craig Ringer <craig(at)2ndquadrant(dot)com> |
| Subject: | Re: INSERT ... ON CONFLICT {UPDATE | IGNORE} |
| Date: | 2014-09-29 22:08:36 |
| Message-ID: | 1412028516.55942.YahooMailNeo@web122303.mail.ne1.yahoo.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> On 2014-09-29 14:57:45 -0700, Kevin Grittner wrote:
>> The initial implementation could restrict to these exact clauses
>> and require that the boolean-expression used equality-quals on all
>> columns of a unique index on only NOT NULL columns.
>
> That'll make it really hard to actually implement real MERGE.
>
> Because suddenly there's no way for the user to know whether he's
> written a ON condition that can implement UPSERT like properties
> (i.e. the *precise* column list of an index) or not.
Well, unless we abandon transactional semantics for other MERGE
statements, we should have a way that UPSERT logic continues to
work if you don't match a suitable index; it will just be slower --
potentially a lot slower, but that's what indexes are for. I don't
think we need a separate statement type for the one we "do well",
because I don't think we should do the other one without proper
transactional semantics.
--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andres Freund | 2014-09-29 22:09:53 | Re: INSERT ... ON CONFLICT {UPDATE | IGNORE} |
| Previous Message | Peter Geoghegan | 2014-09-29 22:05:46 | Re: INSERT ... ON CONFLICT {UPDATE | IGNORE} |