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From Enis Söztutar <enis....@gmail.com>
Subject Re: [Query:]Table creation with column family in Phoenix
Date Tue, 15 Mar 2016 00:13:20 GMT
Phoenix maintains a column with empty value, because unlike a row-oriented
RDBMS, a NULL column is not represented explicitly in HBase, but implicitly
where the cell is not in HBase at all.

Here is the explanation from phoenix.apache.org:

For CREATE TABLE, an empty key value will also be added for each row so
that queries behave as expected (without requiring all columns to be
projected during scans). For CREATE VIEW, this will not be done, nor will
any HBase metadata be created. Instead the existing HBase metadata must
match the metadata specified in the DDL statement or aERROR 505 (42000):
Table is read only will be thrown.
 Enis

On Fri, Mar 11, 2016 at 2:53 PM, Harish Krishnan <
harish.t.krishnan@gmail.com> wrote:

> Your scan query is returning all states/versions of your columns and column
> families
>
> Thanks & Regards,
> Harish.T.K
>
> On Thu, Mar 10, 2016 at 11:54 PM, Divya Gehlot <divya.htconex@gmail.com>
> wrote:
>
> > Hi,
> > I created a table in Phoenix with three column families  and Inserted the
> > values as shown below
> >
> > Syntax :
> >
> > > CREATE TABLE TESTCF (MYKEY VARCHAR NOT NULL PRIMARY KEY, CF1.COL1
> > VARCHAR,
> > > CF2.COL2 VARCHAR, CF3.COL3 VARCHAR)
> > > UPSERT INTO TESTCF (MYKEY,CF1.COL1,CF2.COL2,CF3.COL3)values
> > > ('Key2','CF1','CF2','CF3')
> > > UPSERT INTO TESTCF (MYKEY,CF1.COL1,CF2.COL2,CF3.COL3)values
> > > ('Key2','CF12','CF22','CF32')
> >
> >
> >  When I try to scan same table in Hbase
> > hbase(main):010:0> scan "TESTCF"
> >
> > > ROW                   COLUMN+CELL
> > >  Key1                 column=CF1:COL1, timestamp=1457682385805,
> value=CF1
> > >  Key1                 column=CF1:_0, timestamp=1457682385805, value=
> > >  Key1                 column=CF2:COL2, timestamp=1457682385805,
> value=CF2
> > >  Key1                 column=CF3:COL3, timestamp=1457682385805,
> value=CF3
> > >  Key2                 column=CF1:COL1, timestamp=1457682426396,
> > value=CF12
> > >  Key2                 column=CF1:_0, timestamp=1457682426396, value=
> > >  Key2                 column=CF2:COL2, timestamp=1457682426396,
> > value=CF22
> > >  Key2                 column=CF3:COL3, timestamp=1457682426396,
> > value=CF32
> > > 2 row(s) in 0.0260 seconds
> >
> >
> > My query is why I am getting CF1:_0 one extra column in each row with no
> > value.
> >
> > Can any body explain me .
> > Would really appreciate the help.
> >
> > Thanks,
> > Divya
> >
>

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