Re: Incrementally refreshed materialized view

On Mon, Sep 26, 2016 at 3:16 PM, Adam Brusselback
<adambrusselback(at)gmail(dot)com> wrote:

> Well I feel like I've learned a ton already reading through the links you
> provided earlier and that example above.

Yeah, I know that example can really help show what will happen
"under the covers", and make it more concrete. The theory that
it's based on seems brilliant to me. That fact that it's based on
relational algebra (RA) means that it is much more likely to be
implemented in a complete and correct manner than something ad hoc.
I know I started at this with a try (similar to yours) at
analyzing from scratch, then went and searched the literature.
When I came back to my ad hoc notes, the RA pointed out some holes
in the logic where corner cases would have been wrong because of
missed details. RA is well thought out and solid; it seems to me
to be the perfect thing to underlie a solution to this problem.

> I'm very interested in getting this into core. I'll look into what I need to
> do to review. Not crazy familiar with C, as I mainly do Java development.
> I'll see if I can help in any way though.

Just testing it and reviewing the documentation for errors,
omissions, or just plain hard-to-follow language would be a big
help. Please post back about any problems getting things patched
and build.

> The main reason I was working on an alternative is because I need something
> now rather than in a couple years, but I've been dealing with manually
> creating the few I do need for my database. What I proposed above was just
> me thinking about what could be done with things as they are. Obviously it's
> junk compared to a real solution in-core. Would you consider my approach
> even worth trying, or should I just suck it up and do things manually for
> now and put that effort into getting incremental refresh into core?

Oh, I've used plain tables and triggers many times myself. If you
need something now, you kind of have to go that route. The
algorithms I cited do provide an interesting potential alternative
for how to go about that, although operating a row at a time you
probably won't approach the speed of statement-level set logic for
statements that affect very many rows. :-(

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company