2017-01-25 12:09 GMT+05:00 Andrew Borodin <boro...@octonica.com>: > 2017-01-24 22:29 GMT+05:00 Jeff Davis <pg...@j-davis.com>: >> By the way, can you show me where the Lehman and Yao paper addresses >> page recycling? > > Here J. Hellerstein comments L&Y paper [1] saying that effectively > there is no deletion algorithm provided. > Here [2] is paper referenced from nbtree docs. I'll check if this is > applicable to GIN B-tree. > > [1] http://db.cs.berkeley.edu/jmh/cs262b/treeCCR.html > [2] http://dl.acm.org/citation.cfm?id=324589
Hi! I'll summarize here my state of studying concurrent methods of page unlinking. GIN B-tree does not have "high key". That means, that rightmost key on a page is maximal for the non-leaf page. But I do not see anything theoretical in a way of implementation of Lanin and Shasha`s methods of page merging, with slight modifications. Their paper does not even mention high key(high fence key in papers by Goetz Graefe). But it's not a simple task due to large portions of shared code between entry tree and posting tree. Also, I do not see a reason why this method can be practically superior to proposed patch. Currently, I do not have resources to implement a proof of concept for fully concurrent page unlinking to make benchmarking. Best regards, Andrey Borodin. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
