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Owen O'Malley edited comment on HIVE-18608 at 2/28/18 12:26 AM: ---------------------------------------------------------------- I've just opened a jira and a pull request that is useful to this and other changes that need to specify column names. https://issues.apache.org/jira/browse/ORC-308 it allows you to specify subfields by name such as your example: myInfoArray.\_elem.emailBody. was (Author: owen.omalley): I've just opened a jira and a pull request that is useful to this and other changes that need to specify column names. https://issues.apache.org/jira/browse/ORC-308 it allows you to specify subfields by name such as your example: myInfoArray._elem_.emailBody. > ORC should allow selectively disabling dictionary-encoding on specified > columns > ------------------------------------------------------------------------------- > > Key: HIVE-18608 > URL: https://issues.apache.org/jira/browse/HIVE-18608 > Project: Hive > Issue Type: New Feature > Components: ORC > Affects Versions: 3.0.0, 2.4.0, 2.2.1 > Reporter: Mithun Radhakrishnan > Assignee: Mithun Radhakrishnan > Priority: Major > Attachments: HIVE-18608.1-branch-2.2.patch > > > Just as ORC allows the choice of columns to enable bloom-filters on, it would > be nice to have a way to specify which columns {{DICTIONARY_V2}} encoding > should be disabled on. > Currently, the choice of dictionary-encoding depends on the results of > sampling the first row-stride within a stripe. If the user knows that a > column's cardinality is bound to prevent an effective dictionary, she might > choose to simply disable it on just that column, and avoid the cost of > sampling in the first row-stride. -- This message was sent by Atlassian JIRA (v7.6.3#76005)