Todd Lipcon created HBASE-6014:
----------------------------------
Summary: Support for block-granularity bitmap indexes
Key: HBASE-6014
URL: https://issues.apache.org/jira/browse/HBASE-6014
Project: HBase
Issue Type: New Feature
Components: regionserver
Reporter: Todd Lipcon
This came up in a discussion with Kannan today, so I promised to write
something brief on JIRA -- this was suggested as a potential summer intern
project. The idea is as follows:
We have several customers who periodically run full table scan MR jobs against
large HBase tables while applying fairly restrictive predicates. The predicates
are often reasonably simple boolean expressions across known columns, and those
columns often are enum-typed or otherwise have a fairly restricted range of
values. For example, a real time process may mark rows as dirty, and a
background MR job may scan for dirty rows in order to perform further
processing like rebuilding inverted indexes.
One way to speed up this type of query is to add bitmap indexes. In the context
of HBase, I would envision this as a new type of metadata block included in the
HFile which has a series of tuples: (qualifier, value range, compressed
bitmap). A 1 bit in the bitmap indicates that the corresponding HFile block has
at least one cell for which a column with the given qualifier falls within the
given range. Queries which have an equality or comparison predicate against an
indexed qualifier can then use the bitmap index to seek directly to those
blocks which may contain relevant data.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
