Congling Xia created KYLIN-4315: ----------------------------------- Summary: use metadata numRows in beeline client for quick row counting Key: KYLIN-4315 URL: https://issues.apache.org/jira/browse/KYLIN-4315 Project: Kylin Issue Type: Improvement Components: Job Engine Reporter: Congling Xia Assignee: Congling Xia
Hi, I find that in `BeelineHiveClient`, method `getHiveTableRows` uses "select count(*) from <tb_name>" for table row counting. The method is invoked in flat intermediate table redistribution step in cube building. This stats can be loaded in metastore. It costs much less time than scanning all rows in Hive table. Since intermediate tables are created and inserted by Kylin, statistics will be automatically calculated and stored in metastore when `[hive.stats.autogather|https://cwiki.apache.org/confluence/display/Hive/Configuration+Properties#ConfigurationProperties-hive.stats.autogather]` is enabled (which is the default setting for Hive). ref Hive wiki for more detail about `numRows` stats: [https://cwiki.apache.org/confluence/display/Hive/StatsDev#StatsDev-ExistingTables%E2%80%93ANALYZE] -- This message was sent by Atlassian Jira (v8.3.4#803005)