yiguolei opened a new pull request, #21141: URL: https://github.com/apache/doris/pull/21141
## Proposed changes In https://github.com/apache/doris/pull/10370, we try to opt string evaluate performance by rewrite the predicate using dict value. But it has to check if the string column is full dict encoding. So that we add a logic to read the last page of the string column to check it. But it has some bad performance for cold data because it has to load the column's ordinal index and zone map index. In some scenario for example, select * from table where pk_col=1. If the query condition is primary key, the result maybe just a few rows but the result may have 100 columns, it will cost a lot of time to load these indices. We could find a lot of time is spending on block_init_time. In my test, a table with 50 string columns and query with primary key. The first read time will reduce from 220ms to 40ms. ## Further comments If this is a relatively large or complex change, kick off the discussion at [d...@doris.apache.org](mailto:d...@doris.apache.org) by explaining why you chose the solution you did and what alternatives you considered, etc... -- 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. To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org 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
