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Date: Fri, 10 Dec 2010 12:52:10 +0100
From: Claudio Martella <claudio.martella@tis.bz.it>
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To: user@hbase.apache.org
Subject: Re: Determine in which row a column exists
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What about a thin table? rowkey:productid columname:clusterid?


On 12/10/10 10:52 AM, G=C3=B6khan =C3=87apan wrote:
> Hi,
>
> We have the output of a clustering algorithm in an hbase table which ha=
s the
> following structure:
>
> {NAME =3D> 'clusters', FAMILIES =3D> [{NAME =3D> 'products', COMPRESS
> true
>  ION =3D> 'NONE', VERSIONS =3D> '3', TTL =3D> '2147483647', BLOCKSIZE =3D=
>
> '655
>  36', IN_MEMORY =3D> 'false', BLOCKCACHE =3D> '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=3Dproducts:21840054,
> timestamp=3D1291817353183, value=3D\x00\x00\x00\x01
>
>  1-1000936175-1879240683-185 column=3Dproducts:23194179,
> timestamp=3D1291817353183, value=3D\x00\x00\x00\x01
>
>  1-1000936175-1879240683-185 column=3Dproducts:23585765,
> timestamp=3D1291817353183, value=3D\x00\x00\x00\x01
>
>  1-1000936175-1879240683-185 column=3Dproducts:24544087,
> timestamp=3D1291817353183, value=3D\x00\x00\x00\x01
>
>
>
> When we want to determine which clusters a product  belongs to, we perf=
orm a
> scan over the table using column,
>
> e.g.
>
> Scan s =3D new Scan();
> s.addColumn(Bytes.toBytes("products"), Bytes.toBytes("24659517"));
> ResultScanner scanner =3D table.getScanner(s);
>
> I am not sure this is the best way, it is slow, could you suggest a fas=
ter
> way to determine such rows?
> Is there a secondary index implementation that we can add to a column f=
amily
> after adding data to table?
>


--=20
Claudio Martella
Digital Technologies
Unit Research & Development - Analyst

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