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From Stephen Connolly <stephen.alan.conno...@gmail.com>
Subject Re: Can a same key exists for two rows in two different column families without clashing ?
Date Wed, 02 Feb 2011 11:01:05 GMT
On 2 February 2011 10:03, Ertio Lew <ertiop93@gmail.com> wrote:
> Can a same key exists for two rows in two different column families without
> clashing ?  Other words, does the same algorithm needs to enforced for
> generating keys for different column families or can different
> algorithms(for generating keys) be enforced on column family basis?
>
> I have tried out that they can, but I wanted to know if there may be any
> problems associated with this.
>
> Thanks.
> Ertio Lew
>

it is a bad analogy for many reasons but if you replace "row key" with
"primary key" and "column family" with "table" then you might get an
answer.

a better analogy is to think of the following.

public class Keyspace {

  public final Map<String,Map<String,byte[]>> columnFamily1;

  public final Map<String,Map<String,byte[]>> columnFamily2;

  public final Map<String,Map<String,Map<String,byte[]>>> superColumnFamily3;

}

(still not quite correct, but mostly so for our purposes);

you are asking given

Keyspace keyspace;
String key1 = makeKeyAlg1();
keyspace.columnFamily1.put(key1,...);

String key2 = makeKeyAlg2();
keyspace.columnFamily2.put(key2,...);

when key1.equals(key2)

then is there a problem?

They are two separate maps... why would there be.

-Stephen

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