HBase
  1. HBase
  2. HBASE-9815

Add Histogram representative of row key distribution inside a region.

    Details

    • Type: New Feature New Feature
    • Status: In Progress
    • Priority: Major Major
    • Resolution: Unresolved
    • Affects Version/s: 0.89-fb
    • Fix Version/s: 0.89-fb
    • Component/s: HFile
    • Labels:
      None

      Description

      Using histogram information, users can parallelize the scan workload into equal sized scans based on the estimated size from the Histogram information. This will help in enabling systems which are trying to perform queries on top of HBase to do cost based optimization while scanning. The Idea is to keep this histogram information in the HFile in the trailer and populate this on compaction and flush.

      The HRegionInterface can expose an API to return the Histogram information of a region, which can be generated by merging histograms of all the hfiles.

      Implementing the histogram on the basis of
      http://jmlr.org/papers/volume11/ben-haim10a/ben-haim10a.pdf
      http://dl.acm.org/citation.cfm?id=1951376
      and NumericHistogram from hive.

      1. Histogram-9815.diff
        68 kB
        Manukranth Kolloju

        Activity

        Hide
        Manukranth Kolloju added a comment -

        Attaching the implementation based on the above paper.

        Show
        Manukranth Kolloju added a comment - Attaching the implementation based on the above paper.
        Hide
        Lars Hofhansl added a comment -
        Show
        Lars Hofhansl added a comment - Jesse Yates , FYI.

          People

          • Assignee:
            Manukranth Kolloju
            Reporter:
            Manukranth Kolloju
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            Dates

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              Created:
              Updated:

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