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XiaoXiang Yu commented on KYLIN-3905: ------------------------------------- h3. Return time statistics of global dictionary(without Shrunken Dictionary) !image-2019-03-25-11-29-19-383.png! > Enable shrunken dictionary default > ---------------------------------- > > Key: KYLIN-3905 > URL: https://issues.apache.org/jira/browse/KYLIN-3905 > Project: Kylin > Issue Type: Improvement > Reporter: XiaoXiang Yu > Assignee: XiaoXiang Yu > Priority: Minor > Attachments: image-2019-03-25-11-26-59-198.png, > image-2019-03-25-11-27-26-149.png, image-2019-03-25-11-27-46-175.png, > image-2019-03-25-11-28-14-256.png, image-2019-03-25-11-29-19-383.png > > > When using bitmap measure on a large cardinality column(require global > dictionaty), build base cuboid step need frequent cache swap so it cannot > finished within a reasonable period. > When shrunken dictionary enabled, a new step will be added to build separated > dictionary for each `InputSplit`, Mapper of **BuildBaseCuboid** step only has > to fetch a smaller dictionary for itself, instead of a larger global > dictionary. It will reduce cache swap and make **BuildBaseCuboid** step run > as quicker as possible. -- This message was sent by Atlassian JIRA (v7.6.3#76005)