{"id":1146,"date":"2011-12-19T11:33:00","date_gmt":"2011-12-19T03:33:00","guid":{"rendered":"\/?p=1146"},"modified":"2012-01-12T10:36:08","modified_gmt":"2012-01-12T02:36:08","slug":"mysql-query-cache","status":"publish","type":"post","link":"https:\/\/blog.vimge.com\/archives\/mysql\/mysql-query-cache.html","title":{"rendered":"MySQL Query Cache \u8fd0\u884c\u53c2\u6570\u53ca\u72b6\u6001\u68c0\u6d4b"},"content":{"rendered":"<p>MySQL\u7684Query Cache\u7cfb\u7edf\u53d8\u91cf\u90fd\u662f\u4ee5\u201cquery_cache\u201c\u4f5c\u4e3a\u524d\u540e\u7f00\u7684\uff0c\u5b83\u4eec\u5206\u522b\u662f\uff1a<\/p>\n<p><strong>have_query_cache<\/strong><br \/>\n<strong>query_cache_limit<\/strong><br \/>\n<strong>query_cache_min_res_unit<\/strong><br \/>\n<strong>query_cache_size<\/strong><br \/>\n<strong>query_cache_type<\/strong><br \/>\n<strong>query_cache_wlock_invalidate<\/strong><\/p>\n<p>\u5176\u4e2d\u201dhave_query_cache\u201c\u53d8\u91cf\u6807\u8bc6\u662fQueryCache\u662f\u5426\u53ef\u7528\u3002\u53ef\u901a\u8fc7\u4ee5\u4e0b\u547d\u4ee4\u67e5\u770b\uff1a<\/p>\n<p><a href=\"http:\/\/doophp.sinaapp.com\/archives\/mysql\/mysql-query-cache.html\/attachment\/qq%e4%ba%94%e7%ac%94%e6%88%aa%e5%9b%be%e6%9c%aa%e5%91%bd%e5%90%8d\" rel=\"attachment wp-att-1300\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-1300\" title=\"QQ\u4e94\u7b14\u622a\u56fe\u672a\u547d\u540d\" src=\"http:\/\/doophp-wordpress.stor.sinaapp.com\/uploads\/2011\/12\/QQ\u4e94\u7b14\u622a\u56fe\u672a\u547d\u540d.jpg\" alt=\"\" width=\"560\" height=\"120\" srcset=\"https:\/\/blog.vimge.com\/wp-content\/uploads\/2011\/12\/QQ\u4e94\u7b14\u622a\u56fe\u672a\u547d\u540d.jpg 560w, https:\/\/blog.vimge.com\/wp-content\/uploads\/2011\/12\/QQ\u4e94\u7b14\u622a\u56fe\u672a\u547d\u540d-150x32.jpg 150w, https:\/\/blog.vimge.com\/wp-content\/uploads\/2011\/12\/QQ\u4e94\u7b14\u622a\u56fe\u672a\u547d\u540d-300x64.jpg 300w\" sizes=\"(max-width: 560px) 100vw, 560px\" \/><\/a><\/p>\n<p>\u901a\u5e38\u8fd9\u4e2a\u53d8\u91cf\u503c\u4e3aYES\uff0c\u5373\u4f7fQueryCache\u529f\u80fd\u4e0d\u53ef\u7528\u7684\u65f6\u5019\uff1a\u5f53\u201cquery_cache_size\u201d\u7684\u503c\u4e3a0\u7684\u65f6\u5019\uff0c\u5373\u4f7f&#8221;have_query_cache=YES&#8221;,QueryCache\u4e5f\u4e0d\u53ef\u7528\u3002<\/p>\n<p><span><span style=\"color: #ff0000;\"><strong>\u6807\u51c6\u7248MySQL\u4e2d\u201cquery_cache_size\u201d\u4e3a0\uff0c\u4e5f\u5373\uff0c\u9ed8\u8ba4\u914d\u7f6e\u4e0bQueryCache\u662f\u4e0d\u53ef\u7528\u7684\u3002<\/strong><\/span><\/span><\/p>\n<p>\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u914d\u7f6e\u6587\u4ef6\u3001\u542f\u52a8\u53c2\u6570\u548c\u547d\u4ee4\u8bbe\u7f6e\u76f8\u5173\u53c2\u6570\u3002\u5982\u901a\u8fc7&#8221;SET&#8221;\u547d\u4ee4\u8bbe\u7f6e\u201cquery_cache_size\u201d:<\/p>\n<p><span><strong>\u5168\u5c40\u8bbe\u7f6e\uff1a<\/strong>mysql&gt; <\/span><span>SET GLOBAL query_cache_size = 1048576;<br \/>\n<\/span><strong>\u4f1a\u8bdd\u8bbe\u7f6e\uff1a<\/strong>mysql&gt; SET SESSION query_cache_size = 1048576;<\/p>\n<p><span><strong>\u00a0\u00a0<\/strong><\/span><strong>\u00a0\u00a0<\/strong><strong>\u00a0\u00a0<\/strong>\u5982\u679c\u4f60\u4f7f\u7528\u7684\u65f6\u5019\u6807\u51c6\u00a0MySQL \u5206\u53d1\u7248\u7684\u8bdd\uff0cQuery Cache \u529f\u80fd\u9ed8\u8ba4\u90fd\u662f\u6253\u5f00\u7684\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u8c03\u6574 MySQL Server \u7684\u53c2\u6570\u9009\u9879\u6253\u5f00\u8be5\u529f\u80fd\u3002\u5b83\u4eec\u4e3b\u8981\u7531\u4ee5\u4e0b5\u4e2a\u53c2\u6570\u6784\u6210\uff1a<\/p>\n<ul>\n<li>query_cache_limit\uff1a\u5141\u8bb8 Cache \u7684\u5355\u6761 Query \u7ed3\u679c\u96c6\u7684\u6700\u5927\u5bb9\u91cf\uff0c\u9ed8\u8ba4\u662f1MB\uff0c\u8d85\u8fc7\u6b64\u53c2\u6570\u8bbe\u7f6e\u7684 Query \u7ed3\u679c\u96c6\u5c06\u4e0d\u4f1a\u88ab Cache<\/li>\n<li>query_cache_min_res_unit\uff1a\u8bbe\u7f6e Query Cache \u4e2d\u6bcf\u6b21\u5206\u914d\u5185\u5b58\u7684\u6700\u5c0f\u7a7a\u95f4\u5927\u5c0f\uff0c\u4e5f\u5c31\u662f\u6bcf\u4e2a Query \u7684 Cache \u6700\u5c0f\u5360\u7528\u7684\u5185\u5b58\u7a7a\u95f4\u5927\u5c0f<\/li>\n<li>query_cache_size\uff1a\u8bbe\u7f6e Query Cache \u6240\u4f7f\u7528\u7684\u5185\u5b58\u5927\u5c0f\uff0c\u9ed8\u8ba4\u503c\u4e3a0\uff0c\u5927\u5c0f\u5fc5\u987b\u662f1024\u7684\u6574\u6570\u500d\uff0c\u5982\u679c\u4e0d\u662f\u6574\u6570\u500d\uff0cMySQL \u4f1a\u81ea\u52a8\u8c03\u6574\u964d\u4f4e\u6700\u5c0f\u91cf\u4ee5\u8fbe\u52301024\u7684\u500d\u6570\u3002<br \/>\n<em><span style=\"color: #ff0000;\">query_cache_size\u6700\u5c0f\u503c\u4e0d\u80fd\u5c0f\u4e8e40KB\uff0c\u5426\u5219\u7cfb\u7edf\u5c06\u4f1a\u4ea7\u751f\u4e00\u4e2aWARNING:Query cache failed to set size 39936;new query cache size is 0.<\/span><\/em><\/li>\n<li>query_cache_type\uff1a\u63a7\u5236 Query Cache \u529f\u80fd\u7684\u5f00\u5173\uff0c\u53ef\u4ee5\u8bbe\u7f6e\u4e3a0(OFF),1(ON)\u548c2(DEMAND)\u4e09\u79cd\uff0c\u610f\u4e49\u5206\u522b\u5982\u4e0b\uff1a\n<ul>\n<li>0(OFF)\uff1a\u5173\u95ed Query Cache \u529f\u80fd\uff0c\u4efb\u4f55\u60c5\u51b5\u4e0b\u90fd\u4e0d\u4f1a\u4f7f\u7528 Query Cache<\/li>\n<li>1(ON)\uff1a\u5f00\u542f Query Cache \u529f\u80fd\uff0c\u4f46\u662f\u5f53 SELECT \u8bed\u53e5\u4e2d\u4f7f\u7528\u7684 SQL_NO_CACHE \u63d0\u793a\u540e\uff0c\u5c06\u4e0d\u4f7f\u7528Query Cache<\/li>\n<li>2(DEMAND)\uff1a\u5f00\u542f Query Cache \u529f\u80fd\uff0c\u4f46\u662f\u53ea\u6709\u5f53 SELECT \u8bed\u53e5\u4e2d\u4f7f\u7528\u4e86 SQL_CACHE \u63d0\u793a\u540e\uff0c\u624d\u4f7f\u7528 Query Cache<\/li>\n<\/ul>\n<\/li>\n<li>query_cache_wlock_invalidate\uff1a\u63a7\u5236\u5f53\u6709\u5199\u9501\u5b9a\u53d1\u751f\u5728\u8868\u4e0a\u7684\u65f6\u523b\u662f\u5426\u5148\u5931\u6548\u8be5\u8868\u76f8\u5173\u7684 Query Cache\uff0c\u5982\u679c\u8bbe\u7f6e\u4e3a 1(TRUE)\uff0c\u5219\u5728\u5199\u9501\u5b9a\u7684\u540c\u65f6\u5c06\u5931\u6548\u8be5\u8868\u76f8\u5173\u7684\u6240\u6709 Query Cache\uff0c\u5982\u679c\u8bbe\u7f6e\u4e3a0(FALSE)\u5219\u5728\u9501\u5b9a\u65f6\u523b\u4ecd\u7136\u5141\u8bb8\u8bfb\u53d6\u8be5\u8868\u76f8\u5173\u7684 Query Cache\u3002<\/li>\n<\/ul>\n<div>\n<p><strong>\u7cfb\u7edf\u7684 Query Cache \u7684\u8fd0\u884c\u72b6\u6001\u53c2\u6570<\/strong><br \/>\nMySQL \u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u7684 Global Status \u6765\u8bb0\u5f55 Query Cache \u7684\u5f53\u524d\u72b6\u6001\uff0c\u5177\u4f53\u5982\u4e0b\uff1a<\/p>\n<ul>\n<li>Qcache_free_blocks\uff1a\u76ee\u524d\u8fd8\u5904\u4e8e\u7a7a\u95f2\u72b6\u6001\u7684 Query Cache \u4e2d\u5185\u5b58 Block \u6570\u76ee<\/li>\n<li>Qcache_free_memory\uff1a\u76ee\u524d\u8fd8\u5904\u4e8e\u7a7a\u95f2\u72b6\u6001\u7684 Query Cache \u5185\u5b58\u603b\u91cf<\/li>\n<li>Qcache_hits\uff1aQuery Cache \u547d\u4e2d\u6b21\u6570<\/li>\n<li>Qcache_inserts\uff1a\u5411 Query Cache \u4e2d\u63d2\u5165\u65b0\u7684 Query Cache \u7684\u6b21\u6570\uff0c\u4e5f\u5c31\u662f\u6ca1\u6709\u547d\u4e2d\u7684\u6b21\u6570<\/li>\n<li>Qcache_lowmem_prunes\uff1a\u5f53 Query Cache \u5185\u5b58\u5bb9\u91cf\u4e0d\u591f\uff0c\u9700\u8981\u4ece\u4e2d\u5220\u9664\u8001\u7684 Query Cache \u4ee5\u7ed9\u65b0\u7684 Cache \u5bf9\u8c61\u4f7f\u7528\u7684\u6b21\u6570<\/li>\n<li>Qcache_not_cached\uff1a\u6ca1\u6709\u88ab Cache \u7684 SQL \u6570\uff0c\u5305\u62ec\u65e0\u6cd5\u88ab Cache \u7684 SQL \u4ee5\u53ca\u7531\u4e8e query_cache_type \u8bbe\u7f6e\u7684\u4e0d\u4f1a\u88ab Cache \u7684 SQL<\/li>\n<li>Qcache_queries_in_cache\uff1a\u76ee\u524d\u5728 Query Cache \u4e2d\u7684 SQL \u6570\u91cf<\/li>\n<li>Qcache_total_blocks\uff1aQuery Cache \u4e2d\u603b\u7684 Block \u6570\u91cf<\/li>\n<\/ul>\n<p>\u53ef\u4ee5\u6839\u636e\u8fd9\u51e0\u4e2a\u72b6\u6001\u8ba1\u7b97\u51fa Cache \u547d\u4e2d\u7387\uff0c\u8ba1\u7b97\u51fa Query Cache \u5927\u5c0f\u8bbe\u7f6e\u662f\u5426\u8db3\u591f\uff0c\u901a\u5e38\u4e0d\u5efa\u8bae\u5c06 Query Cache \u7684\u5927\u5c0f\u8bbe\u7f6e\u8d85\u8fc7256MB\uff0c\u8fd9\u4e5f\u662f\u4e1a\u754c\u6bd4\u8f83\u5e38\u7528\u7684\u505a\u6cd5\u3002<\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>MySQL\u7684Query Cache\u7cfb\u7edf\u53d8\u91cf\u90fd\u662f\u4ee5\u201cquery_cache\u201c\u4f5c\u4e3a\u524d\u540e\u7f00\u7684\uff0c\u5b83\u4eec\u5206\u522b\u662f\uff1a<\/p>\n<p><b>have_query_cache<\/b><br \/><b>query_cache_limit<\/b><br \/><b>query_cache_min_res_unit<\/b><br \/><b>query_cache_size<\/b><br \/><b>query_cache_type<\/b><br \/><b>query_cache_wlock_invalidate<\/b><\/p>\n<p>\u5176\u4e2d\u201dhave_query_cache\u201c\u53d8\u91cf\u6807\u8bc6\u662fQueryCache\u662f\u5426\u53ef\u7528\u3002\u53ef\u901a\u8fc7\u4ee5\u4e0b\u547d\u4ee4\u67e5\u770b\uff1a<\/p>\n<p><span><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[7],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/posts\/1146"}],"collection":[{"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/comments?post=1146"}],"version-history":[{"count":3,"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/posts\/1146\/revisions"}],"predecessor-version":[{"id":1302,"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/posts\/1146\/revisions\/1302"}],"wp:attachment":[{"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/media?parent=1146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/categories?post=1146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.vimge.com\/wp-json\/wp\/v2\/tags?post=1146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}