accumulo update

["panqingcui@163.com" <pa...@163.com>]

In accumulo, how to update the data?
    rowkey columnFamily,columnQualifier,columnVisibility is same, But the values are different,Now the library saved many of the same data.
    Only one columnQualifier value is added in the process, is the current time, now found that the data are there, not updated.
  Use BatchWriter to save, scanner, WholeRowIterator query
  



panqingcui@163.com

Re: accumulo update

[Josh Elser <jo...@gmail.com>]

When you don't include the timestamp when you call Mutation.put(...), 
the server will assign the timestamp. This is normally OK to let the 
server do for you, but will introduce non-determinism when you are 
writing updates to the same Key in rapid succession.

In other words, if your client is writing different Values for the same 
Key, you should make sure you set the timestamp on the update for the 
Mutation. The value you see querying the data will be the value whose 
Key had the largest timestamp.

(this is all assuming that you still have the Versioning Iterator set on 
your table which is the default)

panqingcui@163.com wrote:
> In accumulo, how to update the data?
>      rowkey columnFamily,columnQualifier,columnVisibility is same, But the values are different,Now the library saved many of the same data.
>      Only one columnQualifier value is added in the process, is the current time, now found that the data are there, not updated.
>    Use BatchWriter to save, scanner, WholeRowIterator query
>
>
>
>
> panqingcui@163.com