On 4 August 2016 at 18:27, Bruce Momjian <br...@momjian.us> wrote: >> > Also, why not use this bitmap for all indexes, not just update chains? >> >> I don't understand where you get this update chains thing from. >> >> The bitmap can apply to multiple tuples on one page, which is described. > > I am asking if we could use this idea for all rows on a page, not just > HOT updated, e.g. we have five rows that have col1=4 in an index --- why > not just use on index pointer for all of them, with a bitmap to point to > the possible matches?
Yes. I described that... "The same situation can occur if we have many INSERTs with same values on the same block. This could lead to a reduction in size of the btree for indexes with many duplicate values." -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
