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                1. 修改mysql兼容模式; ~~~ mysql> set global sql_mode = 'NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION'; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql> flush privileges; Query OK, 0 rows affected (0.00 sec) ~~~ 2.分頁優化 between ,in 索引,數據類型,limit ~~~ SELECT * FROM table WHERE id BETWEEN 1000000 AND 1000010; SELECT * FROM table WHERE id IN(10000, 100000, 1000000...); ~~~ 3.mysql 使用變量開啟緩存查詢 ~~~ // 開啟查詢緩存 $today = date("Y-m-d"); $r = mysql_query("SELECT username FROM user WHERE signup_date >= '$today'"); ~~~ 4.不使用NOT IN和<>操作 NOT IN和<>操作都不會使用索引將進行全表掃描。NOT IN可以NOT EXISTS代替,id<>3則可使用id>3 or id<3來代替 5.常見配置 1、連接設置 show variables like '%max_connection%'; show status like '%Max_used_connections%'; Max_used_connections/max_connection <=85%,參數配置項的值可對照修改 2、存儲在堆棧中的連接數量 show variables like '%back_log%'; back_log 默認為50 建議修改為 128~512 3、數據連接關閉前等待時間 show variables like '%timeout%'; 修改interactive_timeout wait_timeout 2項的值,默認為28800,建議修改為7200 4、索引緩沖區的大小 show status like '%read%'; 索引未緩存命中率 key_read/key_request_reads ~=0.001~0.01 5、查詢緩沖區的大小(query_cache_size) show variables like '%cache%'; show status like '%qcache%'; 緩存碎片率 Qcache_free_blocks/Qcache_total_blocks <20% 緩存利用率 (query_cache_size-Qcache_free_memory)/query_cache_size<25% 緩存命中率 Qcache_hits/Qcache_inserts>95% 6、順序讀、隨機讀、排序、連接緩沖區的大小,每個線程獨占,建議設置為16MB show status like '%buffer%'; read_buffer_size read_rnd_buffer_size sort_buffer_size join_buffer_size 7、表緩沖區大小 show status like '%tables%'; table_cache 根據 open_tables opented_tables 大小來調整 8、內存表和臨時表 show status like '%table%'; max_heap_table_size tmp_table_size 內存表超過臨時表大小,才需要調整內存表的大小 9、磁盤上臨時表大小 show status like '%tmp%'; (Created_tmp_disk_tables/Created_tmp_tables)*100<25% 10、緩存線程的數量 show variables like '%tmp%'; thread_cache_size 11、并發線程的數量 show variables like '%thread%'; innodb_thread_concurrency (cpu+磁盤)數量的2倍 12、其他 數據和索引緩沖區的大小 innodb_buffer_pool_size 物理內容的80% 日志緩沖區的大小 innodb_log_buffer_size 1~8MB 數據字段和其他數據結構的大小 innodb_additional_mem_pool_size 20MB 事物處理機制 innodb_flush_log_at_trx_commit 0 提交事物不寫入日志,每秒日志文件寫入和flush磁盤 1 每秒或每次事物提交時,日志文件寫入 flush磁盤 2 每次事物提交時,日志文件寫入,每秒flush磁盤 6.復制表 ` create table number like nums ` 7.用存儲過程生成數字輔助表 ~~~ CREATE PROCEDURE pCreateNums ( cnt INT UNSIGNED ) BEGIN DECLARE s INT UNSIGNED DEFAULT 1; TRUNCATE TABLE nums; WHILE s * 2 <= cnt DO BEGIN INSERT INTO nums SELECT a + s FROM Nums; SET s = s * 2; END; END WHILE; END; call pCreateNums(100000) #單獨開啟調用 ` ~~~
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