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From Christian Decker <decker.christ...@gmail.com>
Subject Re: LongType from user input
Date Thu, 30 Sep 2010 19:39:14 GMT
Sorry for my continued questioning, by now I must have bored everyone about
this topic. I have one last question: how do you create such an index? I
found only ColumnFamilyStoreText.testIndexCreate(), but it appears that this
uses internal API, and thus cannot be invoked from a client side or through
JMX, right? From there on I should be able to find my way around the system
:-)

On Thu, Sep 30, 2010 at 4:56 PM, Stu Hood <stu.hood@rackspace.com> wrote:

> Take a look at the get_indexed_slices method in the 0.7.0-beta Thrift
> interface.
>
> -----Original Message-----
> From: "Christian Decker" <decker.christian@gmail.com>
> Sent: Thursday, September 30, 2010 4:38am
> To: user@cassandra.apache.org
> Subject: Re: LongType from user input
>
> I just read through the tickets on Jira, and it appears that indices are
> implemented in the 0.7 source tree, but I cannot find any pointer on how to
> use them. I'll be trying to create a custom CassandraStorage that loads
> data
> through the indices, anyone else interested?
>
> Regards,
> Chris
>
> On Thu, Sep 30, 2010 at 10:56 AM, Aaron Morton <aaron@thelastpickle.com
> >wrote:
>
> > AFAIK indexes are still in dev. The only example is in the
> system_tests.py
> > in the source tree.
> >
> > Aaron
> >
> >
> > On 30 Sep 2010, at 20:10, Christian Decker <decker.christian@gmail.com>
> > wrote:
> >
> > Apparently I have blanked the 0.7 completely out of my memory. I was
> trying
> > to implement application layer indices and ignored the fact that
> Cassandra
> > 0.7 is implementing them by default. I found ticket CASSANDRA-749 about
> the
> > indices and am reading through the code right now, but is there a higher
> > level overview and a tutorial on how to get things started with these
> > indices (and maybe some inner workings)? This might actually solve all of
> my
> > problems I'm having right now :-)
> >
> > Regards,
> > Chris
> >
> >
> > On Mon, Sep 27, 2010 at 3:45 AM, Aaron Morton < <aaron@thelastpickle.com
> >
> > aaron@thelastpickle.com> wrote:
> >
> >> The only thing I can think of is that values need to be in the correct
> >> byte format when used in indexes in 0.7. Take a look at the types.py
> module
> >> in the pycassa client  <http://github.com/pycassa/pycassa>
> >> http://github.com/pycassa/pycassa for an example of which values need
> to
> >> be byte packed.
> >>
> >> How is your pig function working against cassandra? Is it using the
> >> ColumnFamilyRecordReader? . The code in the internal RowIterator for
> that
> >> class has an example calling the cluster to get to the comparators.
> >>
> >> Aaron
> >>
> >>
> >> On 27 Sep, 2010,at 03:11 AM, Christian Decker <<
> decker.christian@gmail.com>
> >> decker.christian@gmail.com> wrote:
> >>
> >> Hi Aaron,
> >>
> >> what changes can I expect in the 0.7 release regarding Comparison and
> >> Parameters? My problem is mainly that I want to take Strings from stdin
> (or
> >> Pig Scripts for that matter) and convert them in such a way that they
> are
> >> interpreted correctly and converted to the corresponding byte
> representation
> >> to use them in column names and keys.
> >>
> >> Regards,
> >> Chris
> >>
> >> On Sun, Sep 26, 2010 at 5:20 AM, Aaron Morton < <
> aaron@thelastpickle.com>
> >> aaron@thelastpickle.com> wrote:
> >>
> >>> Things a changing in v0.7, the row keys are byte arrays.
> >>>
> >>> Not sure I understand your other concerns.
> >>>
> >>> Aaron
> >>>
> >>>
> >>> On 25 Sep 2010, at 08:10, Christian Decker <<
> decker.christian@gmail.com>
> >>> decker.christian@gmail.com> wrote:
> >>>
> >>>
> >>> Thanks for your quick answer, I think I'll use an affix to sort of cast
> >>> the keys, ranges and others from their textual representation (from
> Pig) to
> >>> the desired byte representation, since I just noticed that the keys for
> the
> >>> rows themselfs are always UTF8 interpreted, and since I want to make
> >>> key-range as well as slice queries, I'll be better off this way I
> think.
> >>> I'll just add a 'L' for Long and 'U' for UUID (of any kind).
> >>>  Or is there a better way that I just can't see from my beginners
> angle?
> >>> :-)thing
> >>>
> >>> Regards,
> >>> Chris
> >>>
> >>>
> >>> On Fri, Sep 24, 2010 at 6:35 PM, Tyler Hobbs < <tyler@riptano.com><
> tyler@riptano.com>
> >>> tyler@riptano.com> wrote:
> >>>
> >>>> Yes, you can use describe_keyspace() and then look through the
> results.
> >>>> It's a little ugly in 0.6, but it works
> >>>>
> >>>> - Tyler
> >>>>
> >>>>
> >>>>
> >>>> On Fri, Sep 24, 2010 at 11:25 AM, Christian Decker <<
> decker.christian@gmail.com><decker.christian@gmail.com>
> >>>> decker.christian@gmail.com> wrote:
> >>>>
> >>>>> Well I'm writing a loading function for Pig, and as it happens I
want
> >>>>> to be able to load slices from cassandra which are specified in
the
> pig
> >>>>> script (thus the input from stdin) but the ColumnFamily from which
to
> read
> >>>>> the data is another parameter and some of the CFs have UTF8, UUID,
> TimeUUID
> >>>>> or Long types for their keys and columns, so simply converting
> everything I
> >>>>> get to an 8byte long would break compatibility with the others.
> >>>>> Now thinking about it I attacked the whole problem in a weird way,
> >>>>> since UUID types won't work either.
> >>>>> So let me change my question slightly, is there a way in 0.6 to
> detect
> >>>>> the compareWith type on a running cluster? That way I could convert
> it to
> >>>>> the right type :D
> >>>>>
> >>>>> Regards,
> >>>>> Chris
> >>>>>
> >>>>>
> >>>>> On Fri, Sep 24, 2010 at 6:09 PM, Tyler Hobbs < <tyler@riptano.com><
> tyler@riptano.com>
> >>>>> tyler@riptano.com> wrote:
> >>>>>
> >>>>>> I'm not sure I understand why using this with multiple column
> families
> >>>>>> prevents you from converting it.  Could you clarify this?
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>> On Fri, Sep 24, 2010 at 10:56 AM, Christian Decker <<
> decker.christian@gmail.com><decker.christian@gmail.com>
> >>>>>> decker.christian@gmail.com> wrote:
> >>>>>>
> >>>>>>> Hi all,
> >>>>>>>
> >>>>>>> I'm having quite a dilemma with the CompareWith attribute.
The
> >>>>>>> Problem is that I have numeric IDs that I'd like to use
as row
> keys, only
> >>>>>>> that I also have to offer a possibility to let users input
them
> from std
> >>>>>>> input. Since I cannot ask my users to input an 8byte sequence
> representing
> >>>>>>> the ID they'd like, I was about to turn to UTF8, when I
remembered
> that they
> >>>>>>> are compared lexicographically, so that 100 actually comes
before
> 2, which
> >>>>>>> kills key slices. Also I cannot just code a converter in
since this
> is
> >>>>>>> supposed to be a used with multiple columnfamilies, so just
> converting an
> >>>>>>> integer read into 8bytes isn't going to work either.
> >>>>>>> Any tricks for this one?
> >>>>>>>
> >>>>>>> Regards,
> >>>>>>> Chris
> >>>>>>>
> >>>>>>
> >>>>>>
> >>>>>
> >>>>
> >>>
> >>
> >
>
>
>

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