leborchuk commented on PR #1762: URL: https://github.com/apache/cloudberry/pull/1762#issuecomment-4519452328
Thanks! This is without a doubt a landmark work! I agree with the approach. Yes, GPORCA contains a huge number of logical transformations, but not all of them lead to such changes that the query can be calculated much faster. Let's find out which of the transformations were particularly effective and we will implement them in the PostgreSQL optimizer. Then, the PostgreSQL optimizer will be no worse than GPORCA. Not always, but it can be improved iteratively. Also my experience shows that bottom-up optimizers are faster. The work is so extensive that it takes time for a thorough review. At the same time, for the most part we are talking about logical transformations of queries, where the price of a mistake is not performance, but a wrong answer. So (take for example the first transformation - CTE Predicate Pushdown via OR Collection and CNF Conversion) I would like to read the original ACMSIGMOD article, its criticism and citations, look at the implementation and tests. It takes time. Is it OK for you if we take **2 months** to review these changes? For my part, I can promise that we (various guys from our team) will provide details as soon as the review of individual changes is performed, rather than accumulating a list of comments. -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
