[jira] Updated: (HADOOP-2291) [hbase] Add row count estimator

["stack (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HADOOP-2291?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

stack updated HADOOP-2291:
--------------------------

    Attachment: Keying.java

Edward:  Here is an extract of code used internally for doing key space estimations.  It won't compile because its been hacked on to remove references to internal, unrelated  packages.  It was originally written by Jim a while back and then subsequently mangled by me.  It might help you w/ this problem though it has a base64 focus (If you want an opinion, these methods, with your cleanup might belong best in hbase/util/Keying.java). 

> [hbase] Add row count estimator
> -------------------------------
>
>                 Key: HADOOP-2291
>                 URL: https://issues.apache.org/jira/browse/HADOOP-2291
>             Project: Hadoop
>          Issue Type: New Feature
>          Components: contrib/hbase
>            Reporter: stack
>            Assignee: Edward Yoon
>            Priority: Minor
>         Attachments: Keying.java
>
>
> Internally we have a little tool that will do a rough estimate of how many rows there are in a dataHbase.  It keeps getting larger and larger partitions running scanners until it turns up > N occupied rows.  Once it has a number > N, it multiples by the partition size to get an approximate row count.  
> This issue is about generalizing this feature so it could sit in the general hbase install.  It would look something like:
> {code}
> long getApproximateRowCount(final Text startRow, final Text endRow, final long minimumCountPerPartition, final long maximumPartitionSize)
> {code}
> Larger minimumCountPerPartition and maximumPartitionSize values would make the count more accurate but would mean the method ran longer.

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