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HBase, mail # user - Set Max Number of Row Versions of a table


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Re: Set Max Number of Row Versions of a table
Nicolas Liochon 2013-09-09, 09:04
Here is an example on trunk. IIRC, with 0.94, you may have to disable the
table before updating the definition.

hbase(main):007:0> create 't2', {NAME => 'f1', VERSIONS => 5}
0 row(s) in 0.2820 seconds

=> Hbase::Table - t2
hbase(main):008:0> describe 't2'
DESCRIPTION
ENABLED
 't2', {NAME => 'f1', DATA_BLOCK_ENCODING => 'NONE', BLOOMFILTER => 'ROW',
REPLICATION_SCOPE => '0', VERSIONS => '5'
true
 , COMPRESSION => 'NONE', MIN_VERSIONS => '0', TTL => '2147483647',
KEEP_DELETED_CELLS => 'false', BLOCKSIZE =>
'655
 36', IN_MEMORY => 'false', ENCODE_ON_DISK => 'true', BLOCKCACHE =>
'true'}

1 row(s) in 0.0050 seconds

hbase(main):011:0> alter 't2', { NAME => 'f1', VERSIONS => 2 }
Updating all regions with the new schema...
0/1 regions updated.
1/1 regions updated.
Done.
0 row(s) in 2.2480 seconds
hbase(main):012:0> describe 't2'
DESCRIPTION
ENABLED
 't2', {NAME => 'f1', DATA_BLOCK_ENCODING => 'NONE', BLOOMFILTER => 'ROW',
REPLICATION_SCOPE => '0', VERSIONS => '2'
true
 , COMPRESSION => 'NONE', MIN_VERSIONS => '0', TTL => '2147483647',
KEEP_DELETED_CELLS => 'false', BLOCKSIZE =>
'655
 36', IN_MEMORY => 'false', ENCODE_ON_DISK => 'true', BLOCKCACHE =>
'true'}

1 row(s) in 0.0040 seconds

On Mon, Sep 9, 2013 at 10:51 AM, Gaetan Deputier <[EMAIL PROTECTED]>wrote:

> I tried on a simple table using the following commands :
>
> create 't', 'f'
>
> alter 't', NAME => 'f', VERSIONS => 5
>
> I have this Error : ERROR: Column family datafVERSIONS5 must have a name
>
> I have tried with the syntax from the alter help page but no success. Any
> hints ?
>
>
> I am running Hbase from Cloudera version 0.94.6-cdh4.3.0.
>
>
> On Mon, Sep 9, 2013 at 1:25 AM, Gaetan Deputier <[EMAIL PROTECTED]
> >wrote:
>
> > Exactly what i was looking for. Thank you very much !
> >
> >
> > On Mon, Sep 9, 2013 at 12:48 AM, Nicolas Liochon <[EMAIL PROTECTED]
> >wrote:
> >
> >> There is a comment in this class that is outdated ("Once set, the
> >> parameters that specify a column cannot be changed without deleting the
> >> column and recreating it. If there is data stored in the column, it will
> >> be
> >> deleted when the column is deleted."). This is from 2007. I will fix
> this.
> >>
> >> It's possible to alter a table after its definition, and you will not
> lose
> >> any data. See the alter command in the shell: alter 't1', NAME ='f1',
> >> VERSIONS => 5
> >>
> >>
> >> On Mon, Sep 9, 2013 at 6:32 AM, Ted Yu <[EMAIL PROTECTED]> wrote:
> >>
> >> > Take a look at HColumnDescriptor#setMaxVersions()
> >> >
> >> > Cheers
> >> >
> >> > On Sun, Sep 8, 2013 at 9:13 PM, Gaetan Deputier <
> >> [EMAIL PROTECTED]
> >> > >wrote:
> >> >
> >> > > Hello Hbase users,
> >> > >
> >> > > Is it possible to set the max number of row versions of a table
> after
> >> its
> >> > > creation ?
> >> > >
> >> > > Sincerely
> >> > >
> >> > > G.
> >> > >
> >> >
> >>
> >
> >
>