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我是新來的stackoverflow，所以這是我的第一槍:)mysqltuner - 需要臨時表的排序
我有我的Mysql數據庫的問題。我遇到了一些性能問題，所以我決定使用mysqltuner。結果是
[--] Up for: 7m 42s (7K q [16.452 qps], 78 conn, TX: 927K, RX: 2M)
[--] Reads/Writes: 86%/14%
[--] Total buffers: 2.1G global + 1.1M per thread (151 max threads)
[OK] Maximum possible memory usage: 2.3G (24% of installed RAM)
[OK] Slow queries: 0% (16/7K)
[OK] Highest usage of available connections: 2% (4/151)
[OK] Key buffer size/total MyISAM indexes: 1.0G/834.4M
[OK] Key buffer hit rate: 99.1% (8M cached/79K reads)
[!!] Query cache efficiency: 0.0% (0 cached/4K selects)
[OK] Query cache prunes per day: 0
[!!] Sorts requiring temporary tables: 376% (2K temp sorts/675 sorts)
[OK] Temporary tables created on disk: 0% (13 on disk/7K total)
[OK] Thread cache hit rate: 94% (4 created/78 connections)
[OK] Table cache hit rate: 26% (102 open/384 opened)
[OK] Open file limit used: 1% (63/5K)
[OK] Table locks acquired immediately: 100% (13K immediate/13K locks)
顯然我有太多的臨時表創建。
但這是什麼意思？這個問題是由缺少索引還是其他問題引起的？
我很感激任何幫助。
謝謝
您在非索引列上使用了'ORDER BY'。 – h2ooooooo
所有列都被編入索引。但我有一些查詢是由一個'SUM（）'子句排序。這是否也會導致這個問題？ – user3531962