The XML API for Geonames contains much more detailed error information
than the JSON one. So, I've converted this plugin to use it instead.
It seems to be the preferred format for Geonames, so biting the bullet
on this makes sense.
Sorting on notice.id when our primary selector was notice_inbox.user_id caused a filesort and table scan of the notice table.
Switchng to notice_inbox's notice_id means we can use our index, and everything comes right up.
Before:
mysql> explain SELECT notice.id AS id FROM notice JOIN notice_inbox ON notice.id = notice_inbox.notice_id WHERE notice_inbox.user_id = 18574 AND notice.repeat_of IS NULL ORDER BY notice.id DESC LIMIT 61 OFFSET 0;
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+----------------------------------------------+
| 1 | SIMPLE | notice_inbox | ref | PRIMARY,notice_inbox_notice_id_idx | PRIMARY | 4 | const | 102600 | Using index; Using temporary; Using filesort |
| 1 | SIMPLE | notice | eq_ref | PRIMARY | PRIMARY | 4 | stoica.notice_inbox.notice_id | 1 | Using index |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+----------------------------------------------+
After:
mysql> explain SELECT notice.id AS id FROM notice JOIN notice_inbox ON notice.id = notice_inbox.notice_id WHERE notice_inbox.user_id = 18574 AND notice.repeat_of IS NULL ORDER BY notice_id DESC LIMIT 61 OFFSET 0;
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+--------------------------+
| 1 | SIMPLE | notice_inbox | ref | PRIMARY,notice_inbox_notice_id_idx | PRIMARY | 4 | const | 102816 | Using where; Using index |
| 1 | SIMPLE | notice | eq_ref | PRIMARY,notice_repeatof_idx | PRIMARY | 4 | stoica.notice_inbox.notice_id | 1 | Using where |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+--------------------------+
Sorting on notice.id when our primary selector was notice_inbox.user_id caused a filesort and table scan of the notice table.
Switchng to notice_inbox's notice_id means we can use our index, and everything comes right up.
Before:
mysql> explain SELECT notice.id AS id FROM notice JOIN notice_inbox ON notice.id = notice_inbox.notice_id WHERE notice_inbox.user_id = 18574 AND notice.repeat_of IS NULL ORDER BY notice.id DESC LIMIT 61 OFFSET 0;
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+----------------------------------------------+
| 1 | SIMPLE | notice_inbox | ref | PRIMARY,notice_inbox_notice_id_idx | PRIMARY | 4 | const | 102600 | Using index; Using temporary; Using filesort |
| 1 | SIMPLE | notice | eq_ref | PRIMARY | PRIMARY | 4 | stoica.notice_inbox.notice_id | 1 | Using index |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+----------------------------------------------+
After:
mysql> explain SELECT notice.id AS id FROM notice JOIN notice_inbox ON notice.id = notice_inbox.notice_id WHERE notice_inbox.user_id = 18574 AND notice.repeat_of IS NULL ORDER BY notice_id DESC LIMIT 61 OFFSET 0;
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+--------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+--------------------------+
| 1 | SIMPLE | notice_inbox | ref | PRIMARY,notice_inbox_notice_id_idx | PRIMARY | 4 | const | 102816 | Using where; Using index |
| 1 | SIMPLE | notice | eq_ref | PRIMARY,notice_repeatof_idx | PRIMARY | 4 | stoica.notice_inbox.notice_id | 1 | Using where |
+----+-------------+--------------+--------+------------------------------------+---------+---------+-------------------------------+--------+--------------------------+
