-- Copyright (c) 2014, 2019, Oracle and/or its affiliates. All rights reserved.
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; version 2 of the License.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program; if not, write to the Free Software
-- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA

--
-- View: schema_index_statistics
--
-- Statistics around indexes.
--
-- Ordered by the total wait time descending - top indexes are most contended.
--
-- mysql> select * from schema_index_statistics limit 5;
-- +------------------+-------------+------------+---------------+----------------+---------------+----------------+--------------+----------------+--------------+----------------+
-- | table_schema     | table_name  | index_name | rows_selected | select_latency | rows_inserted | insert_latency | rows_updated | update_latency | rows_deleted | delete_latency |
-- +------------------+-------------+------------+---------------+----------------+---------------+----------------+--------------+----------------+--------------+----------------+
-- | mem              | mysqlserver | PRIMARY    |          6208 | 108.27 ms      |             0 | 0 ps           |         5470 | 1.47 s         |            0 | 0 ps           |
-- | mem              | innodb      | PRIMARY    |          4666 | 76.27 ms       |             0 | 0 ps           |         4454 | 571.47 ms      |            0 | 0 ps           |
-- | mem              | connection  | PRIMARY    |          1064 | 20.98 ms       |             0 | 0 ps           |         1064 | 457.30 ms      |            0 | 0 ps           |
-- | mem              | environment | PRIMARY    |          5566 | 151.17 ms      |             0 | 0 ps           |          694 | 252.57 ms      |            0 | 0 ps           |
-- | mem              | querycache  | PRIMARY    |          1698 | 27.99 ms       |             0 | 0 ps           |         1698 | 371.72 ms      |            0 | 0 ps           |
-- +------------------+-------------+------------+---------------+----------------+---------------+----------------+--------------+----------------+--------------+----------------+
--

CREATE OR REPLACE
  ALGORITHM = MERGE
  DEFINER = 'mysql.sys'@'localhost'
  SQL SECURITY INVOKER 
VIEW schema_index_statistics (
  table_schema,
  table_name,
  index_name,
  rows_selected,
  select_latency,
  rows_inserted,
  insert_latency,
  rows_updated,
  update_latency,
  rows_deleted,
  delete_latency
) AS
SELECT OBJECT_SCHEMA AS table_schema,
       OBJECT_NAME AS table_name,
       INDEX_NAME as index_name,
       COUNT_FETCH AS rows_selected,
       sys.format_time(SUM_TIMER_FETCH) AS select_latency,
       COUNT_INSERT AS rows_inserted,
       sys.format_time(SUM_TIMER_INSERT) AS insert_latency,
       COUNT_UPDATE AS rows_updated,
       sys.format_time(SUM_TIMER_UPDATE) AS update_latency,
       COUNT_DELETE AS rows_deleted,
       sys.format_time(SUM_TIMER_DELETE) AS delete_latency
  FROM performance_schema.table_io_waits_summary_by_index_usage
 WHERE index_name IS NOT NULL
 ORDER BY sum_timer_wait DESC;
