[ https://issues.apache.org/jira/browse/HIVE-22893?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Zoltan Haindrich updated HIVE-22893: ------------------------------------ Attachment: HIVE-22893.08.patch > Enhance data size estimation for fields computed by UDFs > -------------------------------------------------------- > > Key: HIVE-22893 > URL: https://issues.apache.org/jira/browse/HIVE-22893 > Project: Hive > Issue Type: Improvement > Components: Statistics > Reporter: Zoltan Haindrich > Assignee: Zoltan Haindrich > Priority: Major > Labels: pull-request-available > Attachments: HIVE-22893.01.patch, HIVE-22893.02.patch, > HIVE-22893.03.patch, HIVE-22893.04.patch, HIVE-22893.05.patch, > HIVE-22893.06.patch, HIVE-22893.07.patch, HIVE-22893.08.patch > > Time Spent: 10m > Remaining Estimate: 0h > > Right now if we have columnstat on a column ; we use that to estimate things > about the column; - however if an UDF is executed on a column ; the resulting > column is treated as unknown thing and defaults are assumed. > An improvement could be to give wide estimation(s) in case of frequently used > udf. > For example; consider {{substr(c,1,1)}} ; no matter what the input; the > output is at most a 1 long string -- This message was sent by Atlassian Jira (v8.3.4#803005)