random1 Posted November 23, 2008 Share Posted November 23, 2008 Hey all, I am currently using MONyog to monitor my mySQL databases locally. It advises me that the 'Percentage of full table scans' is at over 73%. It's Thresholds are Warning = 20 Critical = 40 Formula it is using = (Handler_read_rnd_next + Handler_read_rnd) / (Handler_read_rnd_next + Handler_read_rnd + Handler_read_first + Handler_read_next + Handler_read_key + Handler_read_prev) How can I can significantly lower this percentage in mySQL? How do I find out the SQL queries that are performing full table scans? Link to comment https://forums.phpfreaks.com/topic/133862-mysql-and-full-table-scans/ Share on other sites More sharing options...
corbin Posted November 23, 2008 Share Posted November 23, 2008 Indexing usually helps avoid full table scans. Link to comment https://forums.phpfreaks.com/topic/133862-mysql-and-full-table-scans/#findComment-696873 Share on other sites More sharing options...
fenway Posted November 25, 2008 Share Posted November 25, 2008 Indexing usually helps avoid full table scans. Unless you're actually running queries without WHERE clauses, or using indexes with poor cardinality. Link to comment https://forums.phpfreaks.com/topic/133862-mysql-and-full-table-scans/#findComment-698849 Share on other sites More sharing options...
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