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| author | Igor Babaev <igor@askmonty.org> | 2019-02-03 14:56:12 -0800 |
|---|---|---|
| committer | Igor Babaev <igor@askmonty.org> | 2019-02-03 14:56:12 -0800 |
| commit | 658128af43b4d7c6db445164f8ed25ed4d1e3109 (patch) | |
| tree | 7a71580cca55759b8bb2730e117436478948d77f /mysql-test/main/null.result | |
| parent | 5f46670bd09babbee75a24ac82eb4ade0706da66 (diff) | |
| download | mariadb-git-658128af43b4d7c6db445164f8ed25ed4d1e3109.tar.gz | |
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
8d5a11122c32f4d9eb87536886c6e893377bdd07.
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.
Diffstat (limited to 'mysql-test/main/null.result')
| -rw-r--r-- | mysql-test/main/null.result | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mysql-test/main/null.result b/mysql-test/main/null.result index 6601c5e1ed4..fc29f68baf0 100644 --- a/mysql-test/main/null.result +++ b/mysql-test/main/null.result @@ -187,7 +187,7 @@ Warnings: Warning 1265 Data truncated for column 'i' at row 513 explain select * from t1 where i=2 or i is null; id select_type table type possible_keys key key_len ref rows Extra -1 SIMPLE t1 ref i i 4 const 7 Using index +1 SIMPLE t1 ref i i 4 const 8 Using index select count(*) from t1 where i=2 or i is null; count(*) 9 |