Re: Further open item (Was: Status of 7.2)

Huh, a non-zero XMAX is fine.  You mark the XMAX when you _think_ you
are updating it.  It is only expired when the XMAX on the tuple is
committed.

> Or perhaps MAINTAINED INDEX, meaning that it has always both tmin and tmax
> up-to-date.
> Btw 7.2 still has broken behaviour of xmax which by definition should 
> not have a
> non-0 value for live tuples
> 
> pg72b2=# create table parent(pid int primary key);
> NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index 
> 'parent_pkey' for table 'parent'
> CREATE
> pg72b2=# create table child(cid int, pid int references parent);
> NOTICE:  CREATE TABLE will create implicit trigger(s) for FOREIGN KEY 
> check(s)
> CREATE
> pg72b2=# insert into parent values(1);
> INSERT 16809 1
> pg72b2=# insert into child values(1,1);
> INSERT 16810 1
> pg72b2=# update child set pid=2;
> ERROR:  <unnamed> referential integrity violation - key referenced from 
> child not found in parent
> pg72b2=# select xmin,xmax,* from child;
>  xmin | xmax | cid | pid
> ------+------+-----+-----
>   171 |  172 |   1 |   1
> (1 row)

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