HBase, mail # user - Re: when all index block are in block cahe , the scan should use random-read

when all index block are in block cahe , the scan should use random-read

jlei liu 2012-09-03, 09:03

I am using the Hbase0.94 version.
The scan use sequential read in Hbase0.94.

if all index block of one HFile are in block cache , when user set start
key and stop key, we can use *BlockIndexReader.seekToDataBlock(startKey)
and BlockIndexReader.seekToDataBlock(**stopKey) to receive offsets of start
data block and end data block, and then we can use the pread to implement
scan, I think that can improve scan performance.
*

Re: when all index block are in block cahe , the scan should use random-read

yuzhihong@... 2012-09-03, 09:39

Can you log a Jira ?

If you provide a patch, that would be great.

Thanks

On Sep 3, 2012, at 2:03 AM, jlei liu <[EMAIL PROTECTED]> wrote:

> I am using the Hbase0.94 version.
>
>
> The scan use sequential read in Hbase0.94.
>
> if all index block of one HFile are in block cache , when user set start
> key and stop key, we can use *BlockIndexReader.seekToDataBlock(startKey)
> and BlockIndexReader.seekToDataBlock(**stopKey) to receive offsets of start
> data block and end data block, and then we can use the pread to implement
> scan, I think that can improve scan performance.
>
>
> *