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From Andrew Prendergast ...@andrewprendergast.com>
Subject Re: bug report - CQL3 grammar should ignore VARCHAR column length in CREATE statements
Date Tue, 05 Mar 2013 22:10:50 GMT
I think we agree then!

The fact that people misuse Cassandra is a whole separate issue and
shouldn't hold the rest of us back. Adding obfuscation to CQL3 isn't the
solution.

Give me a few more days to put a complete list together of what I think
could be refined in CQL3 then we can pick this up again next week.

I expect it will be a robust discussion :)

ap



On Wed, Mar 6, 2013 at 8:38 AM, Edward Capriolo <edlinuxguru@gmail.com>wrote:

> yes. It doesn't use foreign keys or any constraints, they slow things down.
>
> Exactly what you do not want. Check the history of the "features" that do
> read before write. Counters, the old read before write secondary indexes,
> the new collection functions that impose read before write.
>
> Once people start using them they send an email to cassandra mailing list
> that goes like this:
> "
> Subject: Why is Cassandra so slow?
> Message: I am using secondary indexes and as I write data I seem my
> READ_STAGE is filling up. What is going on? I thought cassandra was faster
> then MySQL? Once my database gets bigger then X GB it slows to a crawl.
> Please help.
> "
> If we make tools that design anti-pattern schema's people will use them, no
> one wins.
>
>
> On Tue, Mar 5, 2013 at 4:30 PM, Andrew Prendergast <
> ap@andrewprendergast.com
> > wrote:
>
> > *>
> >
> >
> http://www.edwardcapriolo.com/roller/edwardcapriolo/entry/schema_vs_schema_less
> > *
> > Thanks for the link Ed, I'm aware of all that.
> >
> > *> Does your the tool handle the fact that foreign keys do not work?
> > *
> > yes. It doesn't use foreign keys or any constraints, they slow things
> down.
> >
> > *> how are your dealing with the fact that a "primary key" in cassandra
> is
> > nothing like a "primary key" in a RDBMS?
> > *
> > locality preserving sequences & natural keys. There are no range queries.
> >
> > *> Generally under the impression that CRUD tools that auto-generate CQL
> > schema's can give someone the rope to hang themselves.
> > *
> > For those of us that know what we are doing and have had to put up with
> SQL
> > based ETL, refining CQL3 would be life changing and ease the transition.
> >
> > ap
> >
> >
> >
> >
> > On Wed, Mar 6, 2013 at 8:08 AM, Edward Capriolo <edlinuxguru@gmail.com
> > >wrote:
> >
> > >
> > >
> >
> http://www.edwardcapriolo.com/roller/edwardcapriolo/entry/schema_vs_schema_less
> > >
> > > Does your the tool handle the fact that foreign keys do not work? Or
> for
> > > that matter, how are your dealing with the fact that a "primary key" in
> > > cassandra is nothing like a "primary key" in a RDBMS?
> > >
> > > Generally under the impression that CRUD tools that auto-generate CQL
> > > schema's can give someone the rope to hang themselves.
> > >
> > > On Tue, Mar 5, 2013 at 3:46 PM, Andrew Prendergast <
> > > ap@andrewprendergast.com
> > > > wrote:
> > >
> > > > Hi Tristan,
> > > >
> > > > I've spent the last couple weekends testing the CRUD DML stuff and
> its
> > > very
> > > > close to meeting that objective (although NULL handling needs some
> > > tuning).
> > > >
> > > > The main hiccups are in the JDBC driver which I have been working
> > through
> > > > with Rick - once he accepts my patches it'll be pretty solid in terms
> > of
> > > > cross-platform compatibility.
> > > >
> > > > On the DDL, I personally have a need for similar compatibility. One
> app
> > > I'm
> > > > working on  programmatically creates the schema for a rather big ETL
> > > > environment. It includes a very nice abstraction that creates
> databases
> > > and
> > > > tables to accommodate tuples as they pass through the pipeline and
> > > behaves
> > > > the same regardless of which DBMS is being used as the storage
> engine.
> > > >
> > > > This is possible because it turns out there is a subset of DDL that
> is
> > > > common to all of the DBMS platforms and it would be very useful to
> see
> > > that
> > > > in Cassandra.
> > > >
> > > > ap
> > > >
> > > >
> > > >
> > > >
> > > > On Tue, Mar 5, 2013 at 8:26 PM, Tristan Tarrant
> > > > <tristan.tarrant@gmail.com>wrote:
> > > >
> > > > > On Tue, Mar 5, 2013 at 10:20 AM, Sylvain Lebresne <
> > > sylvain@datastax.com
> > > > > >wrote:
> > > > >
> > > > > > > This is just one of a few small adjustments that can be
made to
> > the
> > > > > > grammar
> > > > > > > to make everyone's life easier while still maintaining
the
> spirit
> > > of
> > > > > > NOSQL.
> > > > > >
> > > > > > To be clear, I am *not* necessarily against making CQL3 closer
to
> > the
> > > > > > ANSI-SQL
> > > > > > as a convenience. But only if that doesn't compromise the
> language
> > > > > > "integrity"
> > > > > > and is justified. Adding a syntax with a well known semantic
but
> > > > without
> > > > > >
> > > > >
> > > > > To me database DDL (such as the CREATE statement we are talking
> > about)
> > > is
> > > > > always going to be handled in a custom fashion by applications.
> > > > > While ANSI SQL compatibility for CRUD operations is a great
> > objective,
> > > I
> > > > > don't think it really matters for DDL.
> > > > >
> > > > > Tristan
> > > > >
> > > >
> > >
> >
>

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