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From Ryan Rawson <ryano...@gmail.com>
Subject Re: Questions from a friend that I didn't feel comfortable answering...
Date Fri, 13 Aug 2010 18:38:31 GMT
Here are some answers:

On Fri, Aug 13, 2010 at 11:28 AM, Michael Segel
<michael_segel@hotmail.com> wrote:
> Hi,
> A fellow co-worker was asking some questions and while I thought I might know the answer
I wasn't 100% sure that I was right.
> So I figure its better to be safe than sorry, and forward the questions out to the list
because I know that there are a couple of wonks who know this stuff off the top of their head.
:-)(Also its a great way to get the correct answer documented so others can hit Google/Yahoo/<insert
your favorite search engine> and find a response.)
> Here are the questions:
> 1.
> Where is filtering happening?
> Is it on the client or at the read time?

Server side.

> 2.
> In the result
> scanner, when are records delivered to the client?  When I do next? In
> other words what is the penalty for having scan wider than the actual data that
> I need

Records are read at 'next' time.  The penalty of having a wider scan
is you read more data than necessary which increases client<->RS rpc
bandwidth and latency.

> 3.
> Where can I find the
> example of custom WritableByteArrayComparable and Comparator? How do I decide
> which one to overwrite?

I don't understand this question in the context of HBase - you don't
get the ability to choose a comparator for a table.  This is because
rows from tables end up in META and thus you'd have to have multiple
comparators in meta depending on which part of the table we'd be at.

> IMHO I think #3 is a good thing to get documented.
> Thinking of a spatial query where you want to find all of the data from points within
a given volume... It would make life easier.
> TIA!
> -Mike

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