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Comment: Migrated to Confluence 4.0

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  • Indexed Transactional HBase 'ITH' uses secondary tables but handles that transparently for the user.
  • Indexed HBase 'IH' is new in 0.20.3 https://issues.apache.org/jira/browse/HBASE-2037Image Removed compares both approaches. Both approaches don't support multi-valued attributes, so custom secondary tables are used for partition indices.

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  • For equality matches the scan starts at "=value\00" and ends at "=value\01". The trailing null byte and one byte bound the scan to the exact value.
  • For greater-than matches the scan starts at "=value" without an upper bound.
  • For less-than matches the scan stops at "=value" incremented by one bit and without an lower bound.
  • Wiki MarkupFor substring matches a server-side filter is used: "^=<value pattern>\00\[A\-Fa\-f0\-9]\{8}\-\[A\-Fa\-f0\-9]\{4}\-\[A\-Fa\-f0\-9]\{4}\-\[A\-Fa\-f0\-9]\{4}\-\[A\-Fa\-f0\-9]\{12}$"
    If the filter contains an initial pattern the lower bound "=value" and upper bound "=value" incremented by one bit can be set.

It is not possible to obtain a candidate count from that type of index table in constant time. Instead the table must be scanned.

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HBase sorts rows lexicographical by row key. To use the indices for greater-than and lesser-than filters it is important that the byte representation of the normalized values follows that rule. http://brunodumon.wordpress.com/2010/02/17/building-indexes-using-hbase-mapping-strings-numbers-and-dates-onto-bytes/Image Removed provides a good overview.