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From roshandawr...@gmail.com
Subject Re: Newbie question - fetching multiple columns of differentdatatypes and conversion from byte[]
Date Sat, 25 Dec 2010 06:22:41 GMT
Can you please point me an example of that or some Hector API documentation?

I am currently using IndexedSliceRangeQuery to filter on a 2ndary index and fetching all columns
of the matching rows - using range start/end = null. Can the option you suggest be used with
the 2ndry index filtering? I would appreciate very much seeing an example.

Does it make any performance difference whether that conversion is done by Hector/Cass or
by the app?

Thanks.
Roshan
---------------------------------------------------
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-----Original Message-----
From: Jonathan Ellis <jbellis@gmail.com>
Date: Sat, 25 Dec 2010 00:05:44 
To: user<user@cassandra.apache.org>
Reply-To: user@cassandra.apache.org
Subject: Re: Newbie question - fetching multiple columns of different
 datatypes and conversion from byte[]

Or you can specify the types with the column name instead of doing a slice.

On Fri, Dec 24, 2010 at 11:23 PM, Nate McCall <nate@riptano.com> wrote:
> In the case where you have different value types within the same
> slice, yes, you must handle the conversion yourself and
> ByteBufferSerializer is the easiest way to do that.
>
> On Fri, Dec 24, 2010 at 10:44 PM, Roshan Dawrani
> <roshandawrani@gmail.com> wrote:
>> Hi,
>>
>> I am new to Cassandra and Hector and have a basic question on fetching
>> multiple columns of a row that have mixed data types.
>>
>> So, I am basically doing equivalent of "Select dateCol1, dateCol2,
>> stringCol1, intCol1 from a_table where key in (?, ?, ?...)"
>>
>> My question is do I need to do the conversion of columns from byte[] to
>> Date/String/Int myself after taking out data from the ColumnSlice?
>>
>> For saving the same data, while adding the columns, I was able to tell which
>> serializer to use, but slice queries seem to take only one ValueSerializer
>> for all columns being retrieved. So, if I have got it correctly, I can only
>> use ByteBufferSerializer in the Hector API slice query call and then do
>> further data-type specific conversion myself at the app level?
>>
>> --
>> Roshan
>> Blog: http://roshandawrani.wordpress.com/
>> Twitter: @roshandawrani
>> Skype: roshandawrani
>>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of Riptano, the source for professional Cassandra support
http://riptano.com
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