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From Claudio Martella <claudio.marte...@tis.bz.it>
Subject Re: Determine in which row a column exists
Date Fri, 10 Dec 2010 11:52:10 GMT
What about a thin table? rowkey:productid columname:clusterid?


On 12/10/10 10:52 AM, Gökhan Çapan wrote:
> Hi,
>
> We have the output of a clustering algorithm in an hbase table which has the
> following structure:
>
> {NAME => 'clusters', FAMILIES => [{NAME => 'products', COMPRESS
> true
>  ION => 'NONE', VERSIONS => '3', TTL => '2147483647', BLOCKSIZE =>
> '655
>  36', IN_MEMORY => 'false', BLOCKCACHE => 'true'}]}
>
> row ids are cluster ids.
> Columns in products column family are the id of the products.
>
> an example row is:
>  1-1000936175-1879240683-185 column=products:21840054,
> timestamp=1291817353183, value=\x00\x00\x00\x01
>
>  1-1000936175-1879240683-185 column=products:23194179,
> timestamp=1291817353183, value=\x00\x00\x00\x01
>
>  1-1000936175-1879240683-185 column=products:23585765,
> timestamp=1291817353183, value=\x00\x00\x00\x01
>
>  1-1000936175-1879240683-185 column=products:24544087,
> timestamp=1291817353183, value=\x00\x00\x00\x01
>
>
>
> When we want to determine which clusters a product  belongs to, we perform a
> scan over the table using column,
>
> e.g.
>
> Scan s = new Scan();
> s.addColumn(Bytes.toBytes("products"), Bytes.toBytes("24659517"));
> ResultScanner scanner = table.getScanner(s);
>
> I am not sure this is the best way, it is slow, could you suggest a faster
> way to determine such rows?
> Is there a secondary index implementation that we can add to a column family
> after adding data to table?
>


-- 
Claudio Martella
Digital Technologies
Unit Research & Development - Analyst

TIS innovation park
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Tel. +39 0471 068 123
Fax  +39 0471 068 129
claudio.martella@tis.bz.it http://www.tis.bz.it

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