phpMyAdmin Advisor issues

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#	Issue	Recommendation
	{long_query_time} is set to 10 seconds or more, thus only slow queries that take above 10 seconds are logged.	It is suggested to set long_query_time to a lower value, depending on your environment. Usually a value of 1-5 seconds is suggested.
	The slow query log is disabled.	Enable slow query logging by setting slow_query_log to 'ON'. This will help troubleshooting badly performing queries.
	Suboptimal caching method.	You are using the MySQL Query cache with a fairly high traffic database. It might be worth considering to use memcached instead of the MySQL Query cache, especially if you have multiple slaves.
	Less than 80% of the query cache is being utilized.	This might be caused by query_cache_limit being too low. Flushing the query cache might help as well.
	The query cache is considerably fragmented.	Severe fragmentation is likely to (further) increase Qcache_lowmem_prunes. This might be caused by many Query cache low memory prunes due to query_cache_size being too small. For a immediate but short lived fix you can flush the query cache (might lock the query cache for a long time). Carefully adjusting query_cache_min_res_unit to a lower value might help too, e.g. you can set it to the average size of your queries in the cache using this formula: (query_cache_size - qcache_free_memory) / qcache_queries_in_cache
	Cached queries are removed due to low query cache memory from the query cache.	You might want to increase query_cache_size, however keep in mind that the overhead of maintaining the cache is likely to increase with its size, so do this in small increments and monitor the results.
	Too many sorts are causing temporary tables.	Consider increasing sort_buffer_size and/or read_rnd_buffer_size, depending on your system memory limits.
	There are lots of rows being sorted.	While there is nothing wrong with a high amount of row sorting, you might want to make sure that the queries which require a lot of sorting use indexed columns in the ORDER BY clause, as this will result in much faster sorting.
	There are too many joins without indexes.	This means that joins are doing full table scans. Adding indexes for the columns being used in the join conditions will greatly speed up table joins.
	The rate of reading the first index entry is high.	This usually indicates frequent full index scans. Full index scans are faster than table scans but require lots of CPU cycles in big tables, if those tables that have or had high volumes of UPDATEs and DELETEs, running 'OPTIMIZE TABLE' might reduce the amount of and/or speed up full index scans. Other than that full index scans can only be reduced by rewriting queries.
	The rate of reading data from a fixed position is high.	This indicates that many queries need to sort results and/or do a full table scan, including join queries that do not use indexes. Add indexes where applicable.
	The rate of reading the next table row is high.	This indicates that many queries are doing full table scans. Add indexes where applicable.
	Many temporary tables are being written to disk instead of being kept in memory.	Increasing max_heap_table_size and tmp_table_size might help. However some temporary tables are always being written to disk, independent of the value of these variables. To eliminate these you will have to rewrite your queries to avoid those conditions (Within a temporary table: Presence of a BLOB or TEXT column or presence of a column bigger than 512 bytes) as mentioned in the MySQL Documentation
	MyISAM key buffer (index cache) % used is low.	You may need to decrease the size of key_buffer_size, re-examine your tables to see if indexes have been removed, or examine queries and expectations about what indexes are being used.
	Too many table locks were not granted immediately.	Optimize queries and/or use InnoDB to reduce lock wait.
	The maximum amount of used connections is getting close to the value of {max_connections}.	Increase max_connections, or decrease wait_timeout so that connections that do not close database handlers properly get killed sooner. Make sure the code closes database handlers properly.
	Too many connections are aborted.	Connections are usually aborted when they cannot be authorized. This article might help you track down the source.
	Too many clients are aborted.	Clients are usually aborted when they did not close their connection to MySQL properly. This can be due to network issues or code not closing a database handler properly. Check your network and code.
	The InnoDB log file size is not an appropriate size, in relation to the InnoDB buffer pool.	Especially on a system with a lot of writes to InnoDB tables you should set innodb_log_file_size to 25% of innodb_buffer_pool_size. However the bigger this value, the longer the recovery time will be when database crashes, so this value should not be set much higher than 256 MiB. Please note however that you cannot simply change the value of this variable. You need to shutdown the server, remove the InnoDB log files, set the new value in my.cnf, start the server, then check the error logs if everything went fine. See also this blog entry

2 설정 예시

long_query_time = 5
slow_query_log = 1
slow_query_log_file     = /var/log/mysql/mariadb-slow.log

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• phpMyAdmin Advisor