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Accumulo >> mail # user >> TimeSpan Iterator


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RE: TimeSpan Iterator
Billie

 

Your comment "Users should be aware that this is not an efficient
operation, though." may help me decide if my current use of a secondary
time index is better then.  Right now I maintain a table that has
timestamps as the rowid whose values are the rowid in a metadata table.
Therefore I do one range scan based on the timestamp.  Then a second
lookup of the metadata rowid.  Is this more efficient?  

 

From: Billie Rinaldi [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, August 28, 2012 11:46
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: TimeSpan Iterator

 

On Tue, Aug 28, 2012 at 6:33 AM, John Armstrong <[EMAIL PROTECTED]> wrote:

On 08/28/2012 09:26 AM, [EMAIL PROTECTED] wrote:

Does anyone know of a TimeSpan Iterator that will fetch rows based on
the accumulo timestamp?

 

We actually wrote our own TimestampRangeIterator and
TimestampSetIterator classes.  I don't know if 1.4 has any in the core
libraries.  It's not very hard though.
There's a TimestampFilter in org.apache.accumulo.core.iterators.user in
1.4.  It uses a range of timestamps.  Users should be aware that this is
not an efficient operation, though.

Billie

NEW: Monitor These Apps!
elasticsearch, apache solr, apache hbase, hadoop, redis, casssandra, amazon cloudwatch, mysql, memcached, apache kafka, apache zookeeper, apache storm, ubuntu, centOS, red hat, debian, puppet labs, java, senseiDB