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From "Dave Latham (JIRA)" <j...@apache.org>
Subject [jira] [Created] (HBASE-14355) Scan different TimeRange for each column family
Date Wed, 02 Sep 2015 19:48:45 GMT
Dave Latham created HBASE-14355:

             Summary: Scan different TimeRange for each column family
                 Key: HBASE-14355
                 URL: https://issues.apache.org/jira/browse/HBASE-14355
             Project: HBase
          Issue Type: New Feature
          Components: Client, regionserver, Scanners
            Reporter: Dave Latham
             Fix For: 2.0.0, 1.3.0, 0.98.15

At present the Scan API supports only table level time range. We have specific use cases that
will benefit from per column family time range. (See background discussion at https://mail-archives.apache.org/mod_mbox/hbase-user/201508.mbox/%3CCAA4mzom00ef5eoXStK0HEtxebY8mQSs61GBVGttgpASpmhQHaw@mail.gmail.com%3E)

There are a couple of choices that would be good to validate.  First - how to update the Scan
API to support family and table level updates.  One proposal would be to add Scan.setTimeRange(byte
family, long minTime, long maxTime), then store it in a Map<byte[], TimeRange>.  When
executing the scan, if a family has a specified TimeRange, then use it, otherwise fall back
to using the table level TimeRange.  Clients using the new API against old region servers
would not get the families correctly filterd.  Old clients sending scans to new region servers
would work correctly.

The other question is how to get StoreFileScanner.shouldUseScanner to match up the proper
family and time range.  It has the Scan available but doesn't currently have available which
family it is a part of.  One option would be to try to pass down the column family in each
constructor path.  Another would be to instead alter shouldUseScanner to pass down the specific
TimeRange to use (similar to how it currently passes down the columns to use which also appears
to be a workaround for not having the family available). 

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