Hi Pengcheng! You are solving important problem, thank you!
> 30 авг. 2021 г., в 13:43, Pengchengliu <pengcheng...@tju.edu.cn> написал(а): > > To resolve this performance problem, we think about a solution which cache > SubtransSLRU to local cache. > First we can query parent transaction id from SubtransSLRU, and copy the > SLRU page to local cache page. > After that if we need query parent transaction id again, we can query it > from local cache directly. A copy of SLRU in each backend's cache can consume a lot of memory. Why create a copy if we can optimise shared representation of SLRU? JFYI There is a related patch to make SimpleLruReadPage_ReadOnly() faster for bigger SLRU buffers[0]. Also Nik Samokhvalov recently published interesting investigation on the topic, but for some reason his message did not pass the moderation. [1] Also it's important to note that there was a community request to move SLRUs to shared_buffers [2]. Thanks! Best regards, Andrey Borodin. [0] https://commitfest.postgresql.org/34/2627/ [1] https://www.postgresql.org/message-id/flat/BE73A0BB-5929-40F4-BAF8-55323DE39561%40yandex-team.ru [2] https://www.postgresql.org/message-id/flat/20180814213500.GA74618%4060f81dc409fc.ant.amazon.com
