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From Jon Haddad <jonathan.had...@gmail.com>
Subject Re: Cassandra 3.10 has partial partition key search but does it result in a table scan?
Date Tue, 09 May 2017 14:24:49 GMT
Nope, I didn’t comment on that query.   I specifically answered your question about "select
* from hello where a='foo' allow filtering;”

The query you’ve listed here looks like it would also do a full table scan (again, I don’t
see how it would be avoided).

I recommend firing up a 3 node cluster using CCM, creating a key space with RF=1, and seeing
what it does.  

> On May 9, 2017, at 9:12 AM, Kant Kodali <kant@peernova.com> wrote:
> 
> Hi,
> 
> Are you saying The following query select max(b) from hello where a='a1' allow filtering;
doesn't result in a table scan? I got the result for this query and yes I just tried tracing
it and looks like it is indeed doing a table scan on ReadStage-2 although I am not sure if
I am interpreting it right? Finally is there anyway to prevent table scan while providing
the partial partition key and get the max b ?
> 
> <Screen Shot 2017-05-09 at 7.07.46 AM.png>
> ​
> 
> 
> On Tue, May 9, 2017 at 6:33 AM, Jon Haddad <jonathan.haddad@gmail.com <mailto:jonathan.haddad@gmail.com>>
wrote:
> I don’t see any way it wouldn’t.  Have you tried tracing it?
> 
> > On May 9, 2017, at 8:32 AM, Kant Kodali <kant@peernova.com <mailto:kant@peernova.com>>
wrote:
> >
> > Hi All,
> >
> > It looks like Cassandra 3.10 has partial partition key search but does it result
in a table scan? for example I can have the following
> >
> > create table hello(
> > a text,
> > b int,
> > c text,
> > d text,
> > primary key((a,b), c)
> > );
> >
> > Now I can do select * from hello where a='foo' allow filtering;// This works in
3.10 but I wonder if this query results in table scan and if so is there any way to limit
such that I get max b?
> >
> > Thanks!
> 
> 


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