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HBase, mail # user - Overwrite a row


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Re: Overwrite a row
Ted Yu 2013-04-20, 02:47
I don't know details about Kristoffer's schema.
If all the column qualifiers are known a priori, mutateRow() should serve
his needs.

HBase allows arbitrary number of columns in a column family. If the schema
is dynamic, mutateRow() wouldn't suffice.
If the column qualifiers are known but the row is very wide (and a few
columns are updated per call), performance would degrade.

Just some factors to consider.

Cheers

On Fri, Apr 19, 2013 at 1:41 PM, Mohamed Ibrahim <[EMAIL PROTECTED]>wrote:

> Actually I do see it in the 0.94 JavaDocs (
>
> http://hbase.apache.org/0.94/apidocs/org/apache/hadoop/hbase/client/HTable.html#mutateRow(org.apache.hadoop.hbase.client.RowMutations)
> ),
> so may be it was added in 0.94.6 even though the jira says fixed in 0.95 .
> I haven't used it though, but it seems that's what you're looking for.
>
> Sorry for confusion.
>
> Mohamed
>
>
> On Fri, Apr 19, 2013 at 4:35 PM, Mohamed Ibrahim <[EMAIL PROTECTED]
> >wrote:
>
> > It seems that 0.95 is not released yet, mutateRow won't be a solution for
> > now. I saw it in the downloads and I thought it was released.
> >
> >
> > On Fri, Apr 19, 2013 at 4:18 PM, Mohamed Ibrahim <[EMAIL PROTECTED]
> >wrote:
> >
> >> Just noticed you want to delete as well. I think that's supported since
> >> 0.95 in mutateRow (
> >>
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html#mutateRow(org.apache.hadoop.hbase.client.RowMutations)).
> >> You can do multiple puts and deletes and they will be performed
> atomically.
> >> So you can remove qualifiers and put new ones.
> >>
> >> Mohamed
> >>
> >>
> >> On Fri, Apr 19, 2013 at 3:44 PM, Kristoffer Sjögren <[EMAIL PROTECTED]
> >wrote:
> >>
> >>> What would you suggest? I want the operation to be atomic.
> >>>
> >>>
> >>> On Fri, Apr 19, 2013 at 8:32 PM, Ted Yu <[EMAIL PROTECTED]> wrote:
> >>>
> >>> > What is the maximum number of versions do you allow for the
> underlying
> >>> > table ?
> >>> >
> >>> > Thanks
> >>> >
> >>> > On Fri, Apr 19, 2013 at 10:53 AM, Kristoffer Sjögren <
> [EMAIL PROTECTED]
> >>> > >wrote:
> >>> >
> >>> > > Hi
> >>> > >
> >>> > > Is it possible to completely overwrite/replace a row in a single
> >>> _atomic_
> >>> > > action? Already existing columns and qualifiers should be removed
> if
> >>> they
> >>> > > do not exist in the data inserted into the row.
> >>> > >
> >>> > > The only way to do this is to first delete the row then insert new
> >>> data
> >>> > in
> >>> > > its place, correct? Or is there an operation to do this?
> >>> > >
> >>> > > Cheers,
> >>> > > -Kristoffer
> >>> > >
> >>> >
> >>>
> >>
> >>
> >
>