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From 陈加俊 <cjjvict...@gmail.com>
Subject Re: Newbie question about scan filters
Date Mon, 06 Dec 2010 02:19:13 GMT
Hi

Do I can use the scan filter ? the HBase that we used is version 0.20.6.

jiajun

On Mon, Dec 6, 2010 at 2:05 AM, Lars George <lars.george@gmail.com> wrote:

> Hi Hari,
>
> The filters are applied server side (aka predicate pushdown). If you
> were to scan and skip you incur extra IO cost. Filters, as they are
> implemented right now are simply skipping and therefore all they can
> do is slightly improve a normal scan performance. In the future you
> might get better performance as they are re-implemented as
> Coprocessors. Also, depending on certain filter criteria we can
> optimize scans by skipping entire store files (since we know it does
> not certain keys or timestamp based values).
>
> Lars
>
> On Sun, Dec 5, 2010 at 6:39 PM, Hari Sreekumar <hsreekumar@clickable.com>
> wrote:
> > Hi
> >
> > What are the differences between using a scan filter and simpli
> > scanning and then filtering using if conditions? Any particular
> > gotchas you need to be careful about while using filters extensively?
> >
> > Hari
> >
>

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