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From Michael Mior <mm...@uwaterloo.ca>
Subject Re: Materialized view rewriting
Date Thu, 25 Feb 2016 14:24:09 GMT
Any suggestions on the best place to hook in and add the materialized
views? It seems like doing so requires the SchemaPlus object corresponding
to the current schema. The current best approach I see is to save a
reference to the parent schema and then pull out the appropriate SchemaPlus
object in getTableMap. This seems like a bit of a hack though.

--
Michael Mior
mmior@uwaterloo.ca

2016-02-24 17:22 GMT-05:00 Julian Hyde <jhyde@apache.org>:

> By the way, interesting that you are interested in Cassandra and
> materialized views. Cassandra announced materialized view support
> recently[1] but they solved only half of a problem (not an
> insignificant half, I hasten to add), namely materialized view
> maintenance. They don't transparently substitute them into the query -
> you have to reference the materialized view explicitly in y our query
> - so in my book they've not delivered materialized view support. If
> you're planning to deliver REAL materialized view support to Cassandra
> that would be awesome.
>
> Julian
>
> [1]
> http://www.datastax.com/dev/blog/new-in-cassandra-3-0-materialized-views
>
>
> On Wed, Feb 24, 2016 at 2:17 PM, Julian Hyde <jhyde@apache.org> wrote:
> > As is typical for complex pieces of code like this, the documentation
> > is in the code (and the unit test). It's probably not what you wanted
> > to hear, but the code mutates quite fast and so if we'd written a
> > design doc a few months ago it would be partially inaccurate.
> >
> > I, Maryann Xue and Amogh Margoor are the main authors of this code.
> >
> > Suggest you find a relevant test case in MaterializationTest (or write
> > a new one) and run it with trace enabled and/or in a debugger. You
> > will see the process of matching an expression to a MV bottom up if
> > you watch each call to UnifyRule.unify.
> >
> > Julian
> >
> >
> > On Wed, Feb 24, 2016 at 1:40 PM, Michael Mior <mmior@uwaterloo.ca>
> wrote:
> >> Is there any documentation anywhere on how the current implementation of
> >> query rewriting for materialized views work? Mostly I'm referring
> >> to MaterializedViewSubstitutionVisitor. There's a lot of code to digest
> >> with not a lot of documentation and it would be helpful to have a
> reference
> >> to refer. Thanks!
> >>
> >> Cheers,
> >> --
> >> Michael Mior
> >> mmior@uwaterloo.ca
>

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