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From Flavio Pompermaier <pomperma...@okkam.it>
Subject Re: Help in designing row key
Date Tue, 02 Jul 2013 17:35:23 GMT
 Thanks for the reply! I thus have two questions more:

1) is it true that filtering on timestamps doesn't affect performance..?
2) could you send me a little snippet of how you would do such a filter (by
row key + timestamps)? For example get all rows whose key starts with
'someid-' and whose timestamps is greater than some timestamp?

Best,
Flavio


On Tue, Jul 2, 2013 at 6:25 PM, Ted Yu <yuzhihong@gmail.com> wrote:

> bq. Using timestamp in row-keys is discouraged
>
> The above is true.
> Prefixing row key with timestamp would create hot region.
>
> bq. should I filter by a simpler row-key plus a filter on timestamp?
>
> You can do the above.
>
> On Tue, Jul 2, 2013 at 9:13 AM, Flavio Pompermaier <pompermaier@okkam.it
> >wrote:
>
> > Hi to everybody,
> >
> > in my use case I have to perform batch analysis skipping old data.
> > For example, I want to process all rows created after a certain
> timestamp,
> > passed as parameter.
> >
> > What is the most effective way to do this?
> > Should I design my row-key to embed timestamp?
> > Or just filtering by timestamp of the row is fast as well? Or what else?
> >
> > Initially I was thinking to compose my key as:
> > timestamp|source|title|type
> >
> > but:
> >
> > 1) Using timestamp in row-keys is discouraged
> > 2) If this design is ok, using this approach I still have problems
> > filtering by timestamp because I cannot found a way to numerically filer
> > (instead of alphanumerically/by string). Example:
> > 1372776400441|something has timestamp lesser
> > than 1372778470913|somethingelse but I cannot filter all row whose key is
> > "numerically" greater than 1372776400441. Is it possible to overcome this
> > issue?
> > 3) If this design is not ok, should I filter by a simpler row-key plus a
> > filter on timestamp? Or what else?
> >
> > Best,
> > Flavio
> >
>



-- 

Flavio Pompermaier
*Development Department
*_______________________________________________
*OKKAM**Srl **- www.okkam.it*

*Phone:* +(39) 0461 283 702
*Fax:* + (39) 0461 186 6433
*Email:* f.pompermaier@okkam.it
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