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https://issues.apache.org/jira/browse/HBASE-11144?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14277123#comment-14277123
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Brian Johnson commented on HBASE-11144:
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Even if you could do the same thing by issuing multiple scans, this filter has
it's uses. If you were using something like rest, thrift or pig to access the
data the filter might be your only practical solution that doesn't do a full
table scan (filterlist)
> Filter to support scanning multiple row key ranges
> --------------------------------------------------
>
> Key: HBASE-11144
> URL: https://issues.apache.org/jira/browse/HBASE-11144
> Project: HBase
> Issue Type: Improvement
> Components: Filters
> Reporter: Jiajia Li
> Assignee: Jiajia Li
> Fix For: 2.0.0, 1.1.0
>
> Attachments: HBASE_11144_4.patch, HBASE_11144_V10.patch,
> HBASE_11144_V11.patch, HBASE_11144_V12.patch, HBASE_11144_V13.patch,
> HBASE_11144_V14.patch, HBASE_11144_V15.patch, HBASE_11144_V16.patch,
> HBASE_11144_V17.patch, HBASE_11144_V18.patch, HBASE_11144_V5.patch,
> HBASE_11144_V6.patch, HBASE_11144_V7.patch, HBASE_11144_V9.patch,
> MultiRowRangeFilter.patch, MultiRowRangeFilter2.patch,
> MultiRowRangeFilter3.patch, hbase_11144_V8.patch
>
>
> HBase is quite efficient when scanning only one small row key range. If user
> needs to specify multiple row key ranges in one scan, the typical solutions
> are: 1. through FilterList which is a list of row key Filters, 2. using the
> SQL layer over HBase to join with two table, such as hive, phoenix etc.
> However, both solutions are inefficient. Both of them can’t utilize the range
> info to perform fast forwarding during scan which is quite time consuming. If
> the number of ranges are quite big (e.g. millions), join is a proper solution
> though it is slow. However, there are cases that user wants to specify a
> small number of ranges to scan (e.g. <1000 ranges). Both solutions can’t
> provide satisfactory performance in such case.
> We provide this filter (MultiRowRangeFilter) to support such use case (scan
> multiple row key ranges), which can construct the row key ranges from user
> specified list and perform fast-forwarding during scan. Thus, the scan will
> be quite efficient.
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