Re: ask for review of MERGE

Kevin Grittner wrote:
> Robert Haas <robertmhaas@gmail.com> wrote:
>  
> > rhaas=# create table concurrent (x integer primary key);
> > NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index
> > "concurrent_pkey" for table "concurrent"
> > CREATE TABLE
> > rhaas=# insert into x values (1);
> > rhaas=# begin;
> > BEGIN
> > rhaas=# insert into concurrent values (2);
> > INSERT 0 1
> > 
> > <switch to a different window>
> > 
> > rhaas=# update concurrent set x=x where x=2;
> > UPDATE 0
>  
> That surprised me.  I would have thought that the INSERT would have
> created an "in doubt" tuple which would block the UPDATE.  What is
> the reason for not doing so?

When Kevin gets surprised, I get worried.  LOL

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +