imay commented on pull request #3915: URL: https://github.com/apache/incubator-doris/pull/3915#issuecomment-646917344
Doris will construct a left-deep tree for the join tables. In the star schema, fact table usually is the biggest table, it will be make the leftmost node by ordering the table by row counts. When doing hash-join, all the right table will be loaded into memory to build a hash table. If the fact table is regarded as build table, the performance will be bad. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
