
Hbase Essentials
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We apply column families, column qualifiers, timestamps, or ranges with the get()
and scan()
operations for limiting the data retrieved. Designing a row key to match the access patterns in every case is not possible, as at times we only need a subset of the data retrieved. Filters provide such a level of fine-grained access, that is, filtering the dataset based on some regular expression. The HBase API provides a filter interface and an abstract class, FilterBase
, under the org.apache.hadoop.hbase.filter
package, which is further extended by many classes such as CompareFilter
, PageFilter
, SkipFilter
, TimeStampsFilter
, and so on, to provide additional functionalities. The following method defined in the Scan
class is used to set an instance of the filter:
setFilter(Filter filter)
: Apply the specified server-side filter when performing the queryTypically, filters can be categorized into multiple types, as follows:
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