Re: Implementing Incremental View Maintenance

Hi hackers,

I attached the updated patch including fixes reported by
Zhihong Yu and Ryohei Takahashi.

Regards,
Yugo Nagata

On Wed, 22 Sep 2021 19:12:27 +0900
Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp> wrote:

> Hello Takahashi-san,
>
> On Mon, 6 Sep 2021 10:06:37 +0000
> "r(dot)takahashi_2(at)fujitsu(dot)com" <r(dot)takahashi_2(at)fujitsu(dot)com> wrote:
>
> > Hi Nagata-san,
> >
> >
> > I'm still reading the patch.
> > I have additional comments.
>
> Thank you for your comments!
>
> >
> > (1)
> > In v23-0001-Add-a-syntax-to-create-Incrementally-Maintainabl.patch, ivm member is added to IntoClause struct.
> > I think it is necessary to modify _copyIntoClause() and _equalIntoClause() functions.
>
> Ok. I'll fix _copyIntoClause() and _equalIntoClause() as well as _readIntoClause() and _outIntoClause().
>
> > (2)
> > By executing pg_dump with v23-0005-Add-Incremental-View-Maintenance-support-to-pg_d.patch,
> > the constraint which is automatically created during "CREATE INCREMENTAL MATERIALIZED VIEW" is also dumped.
> > This cause error during recovery as follows.
> >
> > ivm=# create table t (c1 int, c2 int);
> > CREATE TABLE
> > ivm=# create incremental materialized view ivm_t as select distinct c1 from t;
> > NOTICE: created index "ivm_t_index" on materialized view "ivm_t"
> > SELECT 0
> >
> > Then I executed pg_dump.
> >
> > In the dump, the following SQLs appear.
> >
> > CREATE INCREMENTAL MATERIALIZED VIEW public.ivm_t AS
> > SELECT DISTINCT t.c1
> > FROM public.t
> > WITH NO DATA;
> >
> > ALTER TABLE ONLY public.ivm_t
> > ADD CONSTRAINT ivm_t_index UNIQUE (c1);
> >
> > If I execute psql with the result of pg_dump, following error occurs.
> >
> > ERROR: ALTER action ADD CONSTRAINT cannot be performed on relation "ivm_t"
> > DETAIL: This operation is not supported for materialized views.
>
> Good catch! It was my mistake creating unique constraints on IMMV in spite of
> we cannot defined them via SQL. I'll fix it to use unique indexes instead of
> constraints.
>
> Regards,
> Yugo Nagata
>
> --
> Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>
>
>

--
Yugo NAGATA <nagata(at)sraoss(dot)co(dot)jp>