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The following page has been changed by JimKellerman: http://wiki.apache.org/hadoop/Hbase/UsingBloomFilters ------------------------------------------------------------------------------ + Bloom filters can be enabled on a per-column family basis in HBase. By specifying true for the bloom filter parameter in the constructor for H!ColumnDescriptor or by calling H!ColumnDescriptor.setBloomFilter(true), a [http://portal.acm.org/citation.cfm?id=362692&dl=ACM&coll=portal bloom filter] as defined by Bloom in 1970 will be added to the column family. - Bloom filters can be enabled on a per-column family basis in HBase. By specifying true for the bloom filter parameter in the constructor for HColumnDescriptor or by calling HColumnDescriptor.setBloomFilter(true), a bloom filter - [http://portal.acm.org/citation.cfm?id=362692&dl=ACM&coll=portal bloom filter] as defined by Bloom in 1970 will be added to the column family. - Bloom filters can be instantiated by specifying the vector size and the number of hash functions. Dynamic bloom filters require an additional argument, a threshold for the maximum number of keys to record in a row. + This can be done either at table creation time or by disabling the table and modifying the column through the H!BaseAdmin.modifyColumn API. - Junit testing for these four bloom filters can be found in hbase.regionserver.!TestBloomFilters. + Bloom filters are created using the mechanism specified by [http://www.eecs.harvard.edu/~michaelm/NEWWORK/postscripts/BloomFilterSurvey.pdf Broder and Mitzenmacher] which computes the vector size using 4 hash functions. - '''Additional Resources:''' + Junit testing for bloom filters can be found in hbase.regionserver.!TestBloomFilters. - 1. [http://www.cc.gatech.edu/~manolios/bloom-filters/calculator.html Bloom Filter Calculator] - 1. [http://pages.cs.wisc.edu/~cao/papers/summary-cache/node8.html Bloom Filters - the math] - 1. [http://www.flipcode.com/articles/article_bloomfilters.shtml Coding Bloom Filters] -
