Sure, Tomas. Here is the PG Commitfest link: https://commitfest.postgresql.org/44/4510/ ________________________________ From: Tomas Vondra <tomas.von...@enterprisedb.com> Sent: Monday, August 21, 2023 18:56 To: Jian Guo <gj...@vmware.com>; Hans Buschmann <buschm...@nidsa.net>; pgsql-hackers@lists.postgresql.org <pgsql-hackers@lists.postgresql.org> Cc: Zhenghua Lyu <z...@vmware.com> Subject: Re: Wrong rows estimations with joins of CTEs slows queries by more than factor 500
!! External Email On 8/21/23 10:16, Jian Guo wrote: > Hi hackers, > > I found a new approach to fix this issue, which seems better, so I would > like to post another version of the patch here. The origin patch made > the assumption of the values of Vars from CTE must be unique, which > could be very wrong. This patch examines variables for Vars inside CTE, > which avoided the bad assumption, so the results could be much more > accurate. > No problem with posting a reworked patch to the same thread, but I'll repeat my suggestion to register this in the CF app [1]. The benefit is that people are more likely to notice the patch and also cfbot [2] will run regression tests. [1] https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fcommitfest.postgresql.org%2F&data=05%7C01%7Cgjian%40vmware.com%7C4562125966b248a1e18308dba2353d8f%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C638282121775872407%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=OmMo0lQtSvDFWu8VbI0ZorDpZ3BuxsmkTjagGfnryEc%3D&reserved=0<https://commitfest.postgresql.org/> [2] https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fcfbot.cputube.org%2F&data=05%7C01%7Cgjian%40vmware.com%7C4562125966b248a1e18308dba2353d8f%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C638282121775872407%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=xTYDRybLm0AYyvRNqtN85fZWeUJREshIq7PYhz8bMgU%3D&reserved=0<http://cfbot.cputube.org/> -- Tomas Vondra EnterpriseDB: https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.enterprisedb.com%2F&data=05%7C01%7Cgjian%40vmware.com%7C4562125966b248a1e18308dba2353d8f%7Cb39138ca3cee4b4aa4d6cd83d9dd62f0%7C0%7C0%7C638282121775872407%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=Zn4W8nPFmKxCLQ3XM555UlnM%2F9q1XLkJU5PRxT1VSig%3D&reserved=0<http://www.enterprisedb.com/> The Enterprise PostgreSQL Company !! External Email: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender.
