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HBase, mail # dev - Beware of PREFIX_TREE block encoding


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Re: Beware of PREFIX_TREE block encoding
Ted Yu 2013-10-20, 03:33
Interesting.

>From this graph (HBASE-4676), PREFIX_TREE block encoding is not sensitive
to variation in block size:
https://issues.apache.org/jira/secure/attachment/12500778/SeeksPerSec%20by%20blockSize.png

What was your block size ?
If you don't bypass StoreScanner/KeyValueHeap, would that make a difference
?

Thanks
On Sat, Oct 19, 2013 at 7:34 PM, Vladimir Rodionov
<[EMAIL PROTECTED]>wrote:

> What I wanted to say by this? HBase still does not have block encoding
> which is optimal for both scan and seek (re-seek).
> I do not think these goals are mutually exclusive.
>
>
> Best regards,
> Vladimir Rodionov
> Principal Platform Engineer
> Carrier IQ, www.carrieriq.com
> e-mail: [EMAIL PROTECTED]
>
> ________________________________________
> From: Vladimir Rodionov [[EMAIL PROTECTED]]
> Sent: Saturday, October 19, 2013 7:32 PM
> To: [EMAIL PROTECTED]
> Subject: Beware of PREFIX_TREE block encoding
>
> The scan performance is bad. 10 x slower on my tests than for blocks with
> NONE encoding. I scan data directly from block cache through
> StoreFileScanner (bypassing all StoreScanner/KeyValueHeap stuff). It should
> be clearly stated  that this encoding degrades overall performance
> significantly in favor of data size reduction and is suitable only for Gets
> - not for Scans.
>
> Best regards,
> -Vladimir Rodionov
>
> -
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