Re: [HACKERS] [PATCH] Generic type subscripting

st 9. 9. 2020 v 23:04 odesílatel Justin Pryzby <pryzby(at)telsasoft(dot)com>
napsal:

> On Wed, Aug 05, 2020 at 04:04:22PM +0200, Dmitry Dolgov wrote:
> > > On Sun, Aug 02, 2020 at 12:50:12PM +0200, Pavel Stehule wrote:
> > > >
> > > > > Maybe this could be salvaged by flushing 0005 in its current form
> and
> > > > > having the jsonb subscript executor do something like "if the
> current
> > > > > value-to-be-subscripted is a JSON array, then try to convert the
> textual
> > > > > subscript value to an integer". Not sure about what the error
> handling
> > > > > rules ought to be like, though.
> > > >
> > > > I'm fine with the idea of separating 0005 patch and potentially
> prusuing
> > > > it as an independent item. Just need to rebase 0006, since Pavel
> > > > mentioned that it's a reasonable change he would like to see in the
> > > > final result.
> > >
> > > +1
> >
> > Here is what I had in mind. Worth noting that, as well as the original
>
> This seems to already hit a merge conflict (8febfd185).
> Would you re-rebase ?
>

This can be easy fixed. Maybe I found a another issue.

create table foo(a jsonb);

postgres=# select * from foo;
┌───────────────────────────────────────────────────────────────────┐
│ a │
╞═══════════════════════════════════════════════════════════════════╡
│ [0, null, null, null, null, null, null, null, null, null, "ahoj"] │
└───────────────────────────────────────────────────────────────────┘
(1 row)

It is working like I expect

but

postgres=# truncate foo;
TRUNCATE TABLE
postgres=# insert into foo values('[]');
INSERT 0 1
postgres=# update foo set a[10] = 'ahoj';
UPDATE 1
postgres=# select * from foo;
┌──────────┐
│ a │
╞══════════╡
│ ["ahoj"] │
└──────────┘
(1 row)

Other parts look well. The plpgsql support is not part of this patch, but
it can be the next step. Implemented feature is interesting enough - it is
a simple user friendly interface for work with jsonb and in future with
other types.

Regards

Pavel

> --
> Justin
>