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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: PerRowSecondaryIndex Multiple Load
Date Thu, 19 Jul 2012 23:47:53 GMT
That smells like a bug to me.  I don't see how you can avoid getting
multiple buildIndexAsync calls kicked off.

What do you think, Jake?

On Thu, May 31, 2012 at 4:46 PM, Adam Holmberg
<adam.holmberg.list@gmail.com> wrote:
> I've been studying and experimenting some with the SecondaryIndex API,
> specifically extending the PerRowSecondaryIndex class.
>
> I understand from this recent
> thread<http://mail-archives.apache.org/mod_mbox/cassandra-dev/201205.mbox/%3CCAMYB=b6c9HTDgOFHQS-UwS4UF2a6NiMs3+C++iG3M8z4xgzn=g@mail.gmail.com%3E>that
> this feature is not yet widely used, but I was hoping someone could
> shed some light on its intended concept of operation:
>
> My intuition was to specify my custom index for every column in the column
> family that I want to trigger an update for this index. This has the
> desired effect for a 'built' index as new row mutations arrive. What I'm
> confused about is what happens as the index is built for the first time.
> What I'm seeing is that an asynchronous build is kicked off for every
> column to which this index is attached (which is obviously undesirable).
>
> It's plain to see why this is happening following the SecondaryIndexManager
> reload/addIndexedColumn routines. Now what I'm wondering is if there is
> room for improvement here:
>
> Should the Manager wait to initiate an index build until the last column
> has been added to a given rowLevelIndex? Or is the impetus on the
> PerRowSecondaryIndex implementation to 'fool' the manager into bypassing
> the build until the last column is added?
>
> My gut says the former would be preferred since the latter could be a
> fragile use of the Interface, but I'm just getting into this area and maybe
> I'm thinking about things wrong.
>
> Any input would be appreciated.
>
> Regards,
> Adam Holmberg



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

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