I have defined the secondary index on a field that is part of the primary
key. This should be ok. Maybe you missed the CREATE INDEX bit in my
original post. I might end up not using secondary indexes but since the
feature is there and I need the functionality I would like to know its
limitations and if the behaviour I am experiencing is a problem with my
design, a problem with the data or a problem with Cassandra.
/Petter
Den torsdagen den 24:e oktober 2013 skrev Jan Algermissen:
>
> On 24.10.2013, at 15:13, Petter von Dolwitz (Hem) <
> petter.von.dolw...@gmail.com <javascript:;>> wrote:
>
> > >You cannot use a part in a where clause unless you specify the
> preceeding parts also.
> > But the statement SELECT * FROM mytable WHERE c='myvalue'; works?
> >
> > What are secondary indexes for then if you can't use them in this way?
>
> What you have in your example is parts of a primary key.
>
> Secondary are defined in a different way (I never use them because they
> sort of goes against the whole point of using C* IMHO so I don't know right
> now how to do it. check the docs)
>
> Jan
>
>
> >
> > Forgot to mention that I am on Cassandra 2.0.1
> >
> > /Petter
> >
> >
> > 2013/10/24 Jan Algermissen <jan.algermis...@nordsc.com <javascript:;>>
> > Petter,
> >
> > On 24.10.2013, at 14:38, Petter von Dolwitz (Hem) <
> petter.von.dolw...@gmail.com <javascript:;>> wrote:
> >
> > > Hi,
> > >
> > > I have a table that (in simplified version) looks like this:
> > >
> > > CREATE TABLE mytable (
> > > a varchar,
> > > b varchar,
> > > c varchar
> > > d timstamp,
> > > e varchar,
> > > PRIMARY KEY (a, b, c, d)
> > > );
> > >
> > > CREATE INDEX mytable_c_idx ON mytable ( c );
> > >
> > > After populating I execute:
> > >
> > > SELECT * FROM mytable WHERE c='myvalue';
> > >
> > > which works fine. However, using:
> > >
> > > SELECT * FROM mytable WHERE c IN ('myvalue');
> > >
> > > gives me:
> > > Bad Request: PRIMARY KEY part c cannot be restricted (preceding part b
> is either not restricted or by a non-EQ relation)
> > >
> > > Can anybody explain this?
> >
> > You cannot use a part in a where clause unless you specify the
> preceeding parts also.
> >
> > Think of it this way: To resolve yur restriction, C* would have to do a
> full scan over all rows to find those rows that have a 'myvalue' C-part.
> >
> > Jan
> >
> >
> > > My aim is to query for more than one value in the c column. Is this
> supported?
> > >
> > > Thanks,
> > > Petter
> > >
> > >
> > >
> > >
> > >
> >
> >
>
>
