[
https://issues.apache.org/jira/browse/HBASE-7474?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13543677#comment-13543677
]
Anil Gupta commented on HBASE-7474:
-----------------------------------
[~anoopsamjohn]
Yes, goal of my implementation is to fetch the top N rows of a table sorted by
one column value when the startIndex is 0.
Anoop:How you handle the start index? I guess you have some UI which shows the
results in pages with page size as say 100. So how you are showing page 2,3 etc.
Anil: Yes, that is right. The sorting feature is pretty handy when HBase is
used as Data Source for a web service. We can achieve pagination based on
non-rowkey attribute sorting with the help of this.
In this implementation pageSize is per request basis. So, startIndex tells how
many Top N records to skip.
For example if the request has startIndex as 31 and pageSize as 20. Then Top
30(startIndex-1) records will be ignored and Top 31-50 records will be the
output of the request.
Do you want me to add in the description that Top N query can be done by this?
The jira alreadt says "(similar to "order by" clause of RDBMS)". Is it
ambiguous?
> Endpoint Implementation to support Scans with Sorting of Rows based on column
> values(similar to "order by" clause of RDBMS)
> ---------------------------------------------------------------------------------------------------------------------------
>
> Key: HBASE-7474
> URL: https://issues.apache.org/jira/browse/HBASE-7474
> Project: HBase
> Issue Type: New Feature
> Components: Coprocessors, Scanners
> Affects Versions: 0.94.3
> Reporter: Anil Gupta
> Priority: Minor
> Labels: coprocessors, scan, sort
> Fix For: 0.94.5
>
> Attachments: hbase-7474.patch,
> SortingEndpoint_high_level_flowchart.pdf
>
>
> Recently, i have developed an Endpoint which can sort the Results(rows) on
> the basis of column values. This functionality is similar to "order by"
> clause of RDBMS. I will be submitting this Patch for HBase0.94.3
> I am almost done with the initial development and testing of feature. But, i
> need to write the JUnits for this. I will also try to make design doc.
> Thanks,
> Anil Gupta
> Software Engineer II, Intuit, inc
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
