hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Divya Gehlot <divya.htco...@gmail.com>
Subject Re: [Query:]Table creation with column family in Phoenix
Date Tue, 15 Mar 2016 02:12:44 GMT
Thanks Enis for such a good explanation .

On 15 March 2016 at 08:13, Enis Söztutar <enis.soz@gmail.com> wrote:

> 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
> > >
> >
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message