In a very large MySQL analytics table - should I index the timestamp? - mysql

Question

I'm looking to improve the speed of queries on a very large MySQL analytics table that I have. This table is tracking playercount on gameservers and the structure looks as so:
`server_tracker` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`ip` int(10) unsigned NOT NULL,
`port` smallint(5) unsigned NOT NULL,
`date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
`players` tinyint(3) unsigned NOT NULL,
`map` varchar(28) NOT NULL,
`portjoin` smallint(5) NOT NULL,
PRIMARY KEY (`id`),
KEY `idx_tracking_ip_port` (`ip`,`port`)
) ENGINE=InnoDB AUTO_INCREMENT=310729056 DEFAULT CHARSET=utf8 ROW_FORMAT=FIXED |
This table is inserted into very frequently, with 10k+ servers being tracked 10+ times an hour. However, every hour the data is taken and averaged out, and put into an "averaged" table with basically the same structure.
Currently I have the IP/port setup as key. However - sometimes it can be a tad slow when doing that hourly averaging - so I am curious if it would be worth putting an index on the timestamp, which is frequently used to select data from a certain timeframe like so:
SELECT `players`
FROM `server_tracker`
WHERE `ip` = x
AND `port` = x
AND `date` > NOW()
AND `date` < NOW() + INTERVAL 60 MINUTE
ORDER BY `id` DESC
This is the only type of query ran on this table. The table is only used for fetching the playercount from gameservers within a specific timeframe. The data is never updated or changed.
However, I am a bit new to all of this - and I am not sure if putting an index on the timestamp would do much of anything. Just looking for some friendly advice.
Results of EXPLAIN SELECT players FROM server_tracker WHERE ip = x AND port = x AND date > NOW() AND date < NOW() + INTERVAL 60 MINUTE ORDER BY id DESC
+----+-------------+-----------------+------+----------------------+----------------------+---------+-------------+-------+-------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-----------------+------+----------------------+----------------------+---------+-------------+-------+-------------+
| 1 | SIMPLE | server_tracker | ref | idx_tracking_ip_port | idx_tracking_ip_port | 6 | const,const | 15354 | Using where |
+----+-------------+-----------------+------+----------------------+----------------------+---------+-------------+-------+-------------+

Answer 1

One of the most important information in MySQL and scripts is to know the MySQL to very few exceptions, always just ONE INDEX can be used in a query.
So it does not use much depending on an index ever to set a Column when all 4 are used verfelder in the where clause.
Only a combined index hilt over these fields.
The order of the fields is very important for this index can also be used for other queries.
An example:
An index on field1, field2 and field3 is used when you have the WHERE FIELD1 or FIELD1 and FIELD2 or field1, field2 and FIELD3. This index is not used if you in the WHERE FIELD2 or used FIELD3 or FIELD2 and field. 3 So always use the first field.
Too easy to find out if un like the QUERY works you can just run your query and EXPALIN and beommst directly the information whether and which index is used. If there are several lines you can as an indicator, the individual values ​​under rows muliplizieren together. The smaller this number is the better performs your query.
MariaDB [tmp]> EXPLAIN select * from content;
+------+-------------+---------+------+---------------+------+---------+------+------+-------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+------+-------------+---------+------+---------------+------+---------+------+------+-------+
| 1 | SIMPLE | content | ALL | NULL | NULL | NULL | NULL | 13 | |
+------+-------------+---------+------+---------------+------+---------+------+------+-------+
1 row in set (0.00 sec)
MariaDB [tmp]>
Anternativ you can check out the profiler how long the QUERY in what capacity depends and about optimizing server
An example:
MariaDB [(none)]> use tmp
Database changed
MariaDB [tmp]> SET PROFILING=ON;
Query OK, 0 rows affected (0.00 sec)
MariaDB [tmp]>
MariaDB [tmp]> SELECT * FROM content;
+----+------+---------------------+--------+------+--------------+------+------+------+------+
| id | Wert | Zeitstempel | WertID | aaa | d | e | wwww | n | ddd |
+----+------+---------------------+--------+------+--------------+------+------+------+------+
| 1 | 10 | 2001-01-01 00:00:00 | 1 | NULL | 1.5000 | NULL | NULL | 1 | NULL |
| 2 | 12.3 | 2001-01-01 00:01:00 | 2 | NULL | 2.5000 | NULL | NULL | 2 | NULL |
| 3 | 17.4 | 2001-01-01 00:02:00 | 3 | NULL | 123456.1250 | NULL | NULL | 3 | NULL |
| 4 | 10.9 | 2001-01-01 01:01:00 | 1 | NULL | 1000000.0000 | NULL | NULL | 4 | NULL |
| 5 | 15.4 | 2001-01-01 01:02:00 | 2 | NULL | NULL | NULL | NULL | 5 | NULL |
| 6 | 20.9 | 2001-01-01 01:03:00 | 3 | NULL | NULL | NULL | NULL | 6 | NULL |
| 7 | 22 | 2001-01-02 00:00:00 | 1 | NULL | NULL | NULL | NULL | 7 | NULL |
| 8 | 12.3 | 2001-01-02 00:01:00 | 2 | NULL | NULL | NULL | NULL | 8 | NULL |
| 9 | 17.4 | 2001-01-02 00:02:00 | 3 | NULL | NULL | NULL | NULL |
+----+------+---------------------+--------+------+--------------+------+------+------+------+
13 rows in set (0.00 sec)
MariaDB [tmp]>
MariaDB [tmp]> SHOW PROFILE;
+----------------------+----------+
| Status | Duration |
+----------------------+----------+
| starting | 0.000031 |
| checking permissions | 0.000005 |
| Opening tables | 0.000036 |
| After opening tables | 0.000004 |
| System lock | 0.000003 |
| Table lock | 0.000002 |
| After opening tables | 0.000005 |
| init | 0.000013 |
| optimizing | 0.000006 |
| statistics | 0.000013 |
| preparing | 0.000010 |
| executing | 0.000002 |
| Sending data | 0.000073 |
| end | 0.000003 |
| query end | 0.000003 |
| closing tables | 0.000006 |
| freeing items | 0.000003 |
| updating status | 0.000012 |
| cleaning up | 0.000003 |
+----------------------+----------+
19 rows in set (0.00 sec)
MariaDB [tmp]>