MDEV-16188 Use in-memory PK filters built from range index scans

This patch contains a full implementation of the optimization
that allows to use in-memory rowid / primary filters built for range  
conditions over indexes. In many cases usage of such filters reduce  
the number of disk seeks spent for fetching table rows.

In this implementation the choice of what possible filter to be applied  
(if any) is made purely on cost-based considerations.

This implementation re-achitectured the partial implementation of
the feature pushed by Galina Shalygina in the commit
8d5a11122c.

Besides this patch contains a better implementation of the generic  
handler function handler::multi_range_read_info_const() that
takes into account gaps between ranges when calculating the cost of
range index scans. It also contains some corrections of the
implementation of the handler function records_in_range() for MyISAM.

This patch supports the feature for InnoDB and MyISAM.
This commit is contained in:
Igor Babaev 2019-02-03 14:56:12 -08:00
commit 658128af43
190 changed files with 5644 additions and 1976 deletions

View file

@ -4,6 +4,7 @@ call mtr.add_suppression("Can't find record in .*");
set @mrr_icp_extra_tmp=@@optimizer_switch;
set optimizer_switch='mrr=on,mrr_sort_keys=on,index_condition_pushdown=on';
set optimizer_switch='rowid_filter=off';
SET NAMES latin1;
CREATE TABLE t1
(s1 char(10) COLLATE latin1_german1_ci,