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From Stack <st...@duboce.net>
Subject Re: Will Scan use blockcache?
Date Sat, 29 Dec 2018 15:49:32 GMT
A Get is a one-row Scan. Under the covers the Get makes a Scan. Scan/Get
both have to go to memstore since it will have latest versions of Cells.

Say more about how you are doing the compare please.

S

On Sat, Dec 29, 2018 at 7:02 AM ming.liu <ming.liu@esgyn.cn> wrote:

> Hi, all,
>
>
>
> I recently found that short scan is slower than get operation in HBase. It
> is acceptable, but I really want to understand the reason.
>
>
>
> My testing table only has one row in it. So both Scan and Get just get one
> row. Scan is still about 2x slower than get operation.
>
> So I want to understand the difference between get(rowkey) and Scan(rowkey,
> rowkey).
>
>
>
> I think Get will first match in blockcache, if matched, it will go back
> without accessing HFile/Memstore;
>
> Will Scan search in blockcache as well? Or it directly go to
> memstore/HFile?
>
>
>
> thanks,
>
> Ming
>
>
>
>

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