{"id":3979,"date":"2013-06-16T21:48:36","date_gmt":"2013-06-16T19:48:36","guid":{"rendered":"http:\/\/blog.websupport.sk\/?p=3979"},"modified":"2025-03-11T21:06:19","modified_gmt":"2025-03-11T20:06:19","slug":"efektivne-na-mysql-cast-prva-2","status":"publish","type":"post","link":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/","title":{"rendered":"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1"},"content":{"rendered":"<span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\"><b>Doba \u010d\u00edtania:<\/b><\/span> <span class=\"rt-time\"> 4<\/span> <span class=\"rt-label rt-postfix\">min.<\/span><\/span><p dir=\"ltr\">Na admin oddelen\u00ed sa \u010dasto stret\u00e1vame s r\u00f4znymi probl\u00e9mami na\u0161ich z\u00e1kazn\u00edkov, ktor\u00e9 s\u00fa nie v\u017edy chybou na strane samotn\u00e9ho servera a hostingu ako tak\u00e9ho. Preto sme sa rozhodli p\u00edsa\u0165 seri\u00e1l o r\u00f4znych tipoch, ktor\u00e9 by v\u00e1m mali pom\u00f4c\u0165 pochopi\u0165 a odstr\u00e1ni\u0165 niektor\u00e9 probl\u00e9my so str\u00e1nkami. V tejto \u010dasti sa hlavne za\u010dneme venova\u0165 MySQL datab\u00e1zam.<\/p>\n<p><!--more--><br \/>\nJednou z \u010dast\u00fdch ot\u00e1zok, ktor\u00fa dost\u00e1vame od klientov, je napr. Pre\u010do je r\u00fdchlos\u0165 na\u010d\u00edtania \u00a0str\u00e1nky zrazu ni\u017e\u0161ia ne\u017e po spusten\u00ed? Alebo aj Pri porovn\u00e1van\u00ed r\u00fdchlosti s t\u00fdm, ako mi to be\u017e\u00ed na lok\u00e1lnom PC, je na\u010d\u00edtanie ove\u013ea pomal\u0161ie, pre\u010do? Existuje viacero pr\u00ed\u010din pomal\u0161ieho chodu str\u00e1nok. Jednou z naj\u010dastej\u0161\u00edch je pr\u00e1ve to, \u017ee dotazy na datab\u00e1zu, ktor\u00e9 pri men\u0161om po\u010dte n\u00e1v\u0161tevn\u00edkov a men\u0161om rozsahu datab\u00e1zy neboli tak\u00e9 kritick\u00e9, zrazu zaberaj\u00fa \u010doraz viac \u010dasu.<\/p>\n<p>&nbsp;<\/p>\n<p>Prvou vecou, ktor\u00fa mus\u00edme spravi\u0165, je prejs\u0165 si, ak\u00e9 dotazy n\u00e1m m\u00f4\u017eu sp\u00f4sobova\u0165 probl\u00e9my. Na sledovanie vykon\u00e1vania jednotliv\u00fdch dotazov m\u00f4\u017eeme pou\u017ei\u0165 pr\u00edkaz <em><strong>SHOW processlist;<\/strong><\/em> priamo v phpmyadmine. Pomocou tohto pr\u00edkazu m\u00f4\u017eeme okrem in\u00e9ho vidie\u0165, ako dlho u\u017e dotaz be\u017e\u00ed, jeho identifika\u010dn\u00e9 \u010d\u00edslo, ako aj moment\u00e1lny stav. V r\u00e1mci hostingov WebSupportu vyu\u017e\u00edvame mo\u017enos\u0165 zaznamen\u00e1vania MySQL dotazov trvaj\u00facich pr\u00edli\u0161 dlho do slow query logu, ktor\u00fd m\u00f4\u017eete n\u00e1js\u0165 vo WebAdmine v sekcii Datab\u00e1zy. Pokia\u013e teda h\u013ead\u00e1te pr\u00ed\u010dinu spomalenia str\u00e1nok a podozrievate datab\u00e1zu, toto miesto je v\u00fdhodn\u00e9 v\u017edy pozrie\u0165 \u010do najsk\u00f4r.<\/p>\n<p>Ke\u010f m\u00e1me podchyten\u00fd dotaz, ktor\u00fd sa vykon\u00e1va dlh\u0161\u00ed \u010das, vieme n\u00e1js\u0165 aj detaily toho, \u010do rob\u00ed. Posta\u010d\u00ed ulo\u017ei\u0165 si \u010d\u00edslo dotazu (pokia\u013e prebieha) alebo jeho syntax a n\u00e1sledne MySQL zasla\u0165 dotaz EXPLAIN (<strong><em>EXPLAIN \u010d\u00edslo_procesu;<\/em><\/strong> alebo <em><strong>EXPLAIN \u00a0syntax_pomal\u00e9ho_query;<\/strong><\/em>). N\u00e1sledne m\u00f4\u017eeme r\u00fdchlo zisti\u0165, ak\u00fd objem d\u00e1t (mno\u017estvo spracovan\u00fdch riadkov) \u00a0\u010di a ak\u00e9 sa pou\u017e\u00edvaj\u00fa indexy, \u010di je nutn\u00e9 vytvori\u0165 temporary tabu\u013eky na disku, lebo sa medziv\u00fdsledok nevojde do pam\u00e4te, ako aj medzi ak\u00fdmi typmi premenn\u00fdch porovn\u00e1vame.<\/p>\n<p>&nbsp;<\/p>\n<p dir=\"ltr\"><strong>Indexovanie tabuliek\u00a0<\/strong><\/p>\n<p dir=\"ltr\">Jednou zo z\u00e1kladn\u00fdch mo\u017enost\u00ed, ako optimalizova\u0165 datab\u00e1zu, s\u00fa pr\u00e1ve indexy. \u010casto sa d\u00e1ta v r\u00e1mci st\u013apca daj\u00fa zap\u00edsa\u0165 ove\u013ea efekt\u00edvnej\u0161ie z poh\u013eadu vyh\u013ead\u00e1vania &#8211; \u00a0jednotliv\u00e9 polia m\u00f4\u017eeme upravi\u0165 do podoby hashu alebo bin\u00e1rneho stromu a n\u00e1sledne zoradi\u0165 &#8211; \u00a0ako do kartot\u00e9ky. Ke\u010f MySQL n\u00e1sledne napr. vyber\u00e1 pod\u013ea krit\u00e9ri\u00ed z tabu\u013eky, nemus\u00ed prech\u00e1dza\u0165 cel\u00fd obsah datab\u00e1zy. Naj\u010dastej\u0161ie to u\u017e\u00edvate\u013e datab\u00e1zy m\u00f4\u017ee poc\u00edti\u0165, ke\u010f jeho query ide naprie\u010d viacer\u00fdmi tabu\u013ekami (JOIN) a h\u013eadan\u00ed unik\u00e1tnych z\u00e1znamov (DISTINCT).<\/p>\n<p dir=\"ltr\">Ak chceme spoji\u0165 d\u00e1ta z dvoch tabuliek, je to \u010do sa t\u00fdka rozsahu (a teda aj objemu) spracovan\u00fdch d\u00e1t trocha o\u0161emetn\u00e1 situ\u00e1cia, pokia\u013e by sme chceli h\u013eada\u0165 hrubou silou. N\u00e1ro\u010dnos\u0165 ak\u00e9hoko\u013evek JOIN toti\u017e st\u00fapa s po\u010dtom riadkov a v najhor\u0161om pr\u00edpade rastie a\u017e exponenci\u00e1lne. (Piko\u0161ka: \u017ee to m\u00f4\u017ee by\u0165 a\u017e tak\u00e9 zl\u00e9, som zbadal, ke\u010f som nad datab\u00e1zou ist\u00e9ho f\u00f3ra videl ako dotaz preh\u013ead\u00e1val nieko\u013eko desiatok bili\u00f3nov pol\u00ed. Bili\u00f3nov!)<\/p>\n<p>Na to, aby sme mohli vybera\u0165 naprie\u010d viacer\u00fdmi po\u013eami, potrebujeme toti\u017e najprv z\u00edska\u0165 tak\u00fa tabu\u013eku, kde s\u00fa ku ka\u017edej vybranej kombin\u00e1cii st\u013apcov z prvej tabu\u013eky pridelen\u00e9 pod\u013ea mo\u017enosti relevantn\u00e9 st\u013apce z druhej tabu\u013eky, aby sme potom mohli v\u00f4bec porovn\u00e1va\u0165, ktor\u00e9 riadky sp\u013a\u0148aj\u00fa podmienky vo WHERE.<\/p>\n<p dir=\"ltr\">Pokia\u013e teda vid\u00edme, \u017ee je v dotaze direkt\u00edva \u00a0JOIN (alebo aj LEFT JOIN, a OUTER JOIN) a vid\u00edme, \u017ee sa nepou\u017e\u00edva index, pozrieme, ak\u00e9 st\u013apce s\u00fa v jednotliv\u00fdch tabu\u013ek\u00e1ch pou\u017e\u00edvan\u00e9, pre ktor\u00e9 n\u00e1sledne vytvor\u00edme index. Napr\u00edklad na tabu\u013eke TABLE so st\u013apcami <em>TABLE.id<\/em>, \u00a0<em>TABLE.st\u013apce<\/em>, \u00a0<em>TABLE.ktor\u00e9<\/em>, a \u00a0<em>TABLE.indexova\u0165<\/em> :<\/p>\n<p dir=\"ltr\" style=\"padding-left: 30px;\"><strong><em>\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0CREATE INDEX id_join on TABLE (st\u013apce, ktor\u00e9, indexova\u0165);<\/em><\/strong><\/p>\n<p>&nbsp;<\/p>\n<p>To ist\u00e9 vykon\u00e1me aj pri druhej tabu\u013eke. Indexovanie tabuliek je len jedno z viacer\u00fdch rie\u0161en\u00ed, ako zr\u00fdchli\u0165 na\u010d\u00edtavanie \u00fadajov z datab\u00e1z a v neposlednom rade aj zr\u00fdchli\u0165 odozvu va\u0161ich str\u00e1nok. K \u010fal\u0161\u00edm obvykl\u00fdm \u0165a\u017ekostiam, ako je nespr\u00e1vne pou\u017eitie subquery, nevhodn\u00e9 PHP nastavenia, optimaliz\u00e1ciu sp\u00fa\u0161\u0165an\u00fdch skriptov at\u010f. sa budeme venova\u0165 v \u010fal\u0161\u00edch blogpostoch. D\u00fafame, \u017ee v\u00e1m tento \u010dl\u00e1nok aspo\u0148 trochu objasnil, ako funguje indexovanie v datab\u00e1zach a pre\u010do je jeho pou\u017e\u00edvanie vhodn\u00e9. Nev\u00e1hajte sa podeli\u0165 s va\u0161imi tipmi v koment\u00e1roch.<\/p>\n<p>&nbsp;<\/p>\n<p>Pokia\u013e by ste mali o t\u00fato t\u00e9mu hlb\u0161\u00ed z\u00e1ujem, rozhodne m\u00f4\u017eem odporu\u010di\u0165 nasledovn\u00e9 odkazy:<\/p>\n<p dir=\"ltr\"><a href=\"http:\/\/www.slideshare.net\/osscube\/indexing-the-mysql-index-key-to-performance-tuning\">http:\/\/www.slideshare.net\/osscube\/indexing-the-mysql-index-key-to-performance-tuning<\/a><\/p>\n<p dir=\"ltr\"><a href=\"http:\/\/www.cs.duke.edu\/csl\/docs\/mysql-refman\/optimization.html\">http:\/\/www.cs.duke.edu\/csl\/docs\/mysql-refman\/optimization.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Na admin oddelen\u00ed sa \u010dasto stret\u00e1vame s r\u00f4znymi probl\u00e9mami na\u0161ich z\u00e1kazn\u00edkov, ktor\u00e9 s\u00fa nie v\u017edy chybou na strane samotn\u00e9ho servera a hostingu ako tak\u00e9ho. Preto sme sa rozhodli p\u00edsa\u0165 seri\u00e1l o r\u00f4znych tipoch, ktor\u00e9 by v\u00e1m mali pom\u00f4c\u0165 pochopi\u0165 a odstr\u00e1ni\u0165 niektor\u00e9 probl\u00e9my so str\u00e1nkami. V tejto \u010dasti sa hlavne za\u010dneme venova\u0165 MySQL datab\u00e1zam.<\/p>\n","protected":false},"author":33,"featured_media":5578,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7,8],"tags":[395,526,734],"class_list":["post-3979","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-technologie","category-tipy-a-triky","tag-join","tag-mysql","tag-rychlost-stranok"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.7 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1 - Websupport blog<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/\" \/>\n<meta property=\"og:locale\" content=\"sk_SK\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1 - Websupport blog\" \/>\n<meta property=\"og:description\" content=\"Na admin oddelen\u00ed sa \u010dasto stret\u00e1vame s r\u00f4znymi probl\u00e9mami na\u0161ich z\u00e1kazn\u00edkov, ktor\u00e9 s\u00fa nie v\u017edy chybou na strane samotn\u00e9ho servera a hostingu ako tak\u00e9ho. Preto sme sa rozhodli p\u00edsa\u0165 seri\u00e1l o r\u00f4znych tipoch, ktor\u00e9 by v\u00e1m mali pom\u00f4c\u0165 pochopi\u0165 a odstr\u00e1ni\u0165 niektor\u00e9 probl\u00e9my so str\u00e1nkami. V tejto \u010dasti sa hlavne za\u010dneme venova\u0165 MySQL datab\u00e1zam.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/\" \/>\n<meta property=\"og:site_name\" content=\"Websupport blog\" \/>\n<meta property=\"article:published_time\" content=\"2013-06-16T19:48:36+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2025-03-11T20:06:19+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2015\/01\/cervena_4.png\" \/>\n\t<meta property=\"og:image:width\" content=\"290\" \/>\n\t<meta property=\"og:image:height\" content=\"200\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/png\" \/>\n<meta name=\"author\" content=\"Franti\u0161ek Droj\u00e1k\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Autor\" \/>\n\t<meta name=\"twitter:data1\" content=\"Franti\u0161ek Droj\u00e1k\" \/>\n\t<meta name=\"twitter:label2\" content=\"Predpokladan\u00fd \u010das \u010d\u00edtania\" \/>\n\t<meta name=\"twitter:data2\" content=\"4 min\u00faty\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/\"},\"author\":{\"name\":\"Franti\u0161ek Droj\u00e1k\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#\\\/schema\\\/person\\\/cfe2fdf5ce9bfcd4f149370167e2eae5\"},\"headline\":\"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1\",\"datePublished\":\"2013-06-16T19:48:36+00:00\",\"dateModified\":\"2025-03-11T20:06:19+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/\"},\"wordCount\":884,\"commentCount\":20,\"publisher\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/app\\\/uploads\\\/sites\\\/2\\\/2015\\\/01\\\/cervena_4.png\",\"keywords\":[\"JOIN\",\"MySQL\",\"Rychlost stranok\"],\"articleSection\":[\"Technol\u00f3gie\",\"Tipy a triky\"],\"inLanguage\":\"sk-SK\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/\",\"url\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/\",\"name\":\"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1 - Websupport blog\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/app\\\/uploads\\\/sites\\\/2\\\/2015\\\/01\\\/cervena_4.png\",\"datePublished\":\"2013-06-16T19:48:36+00:00\",\"dateModified\":\"2025-03-11T20:06:19+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#breadcrumb\"},\"inLanguage\":\"sk-SK\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"sk-SK\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#primaryimage\",\"url\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/app\\\/uploads\\\/sites\\\/2\\\/2015\\\/01\\\/cervena_4.png\",\"contentUrl\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/app\\\/uploads\\\/sites\\\/2\\\/2015\\\/01\\\/cervena_4.png\",\"width\":290,\"height\":200},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/2013\\\/06\\\/efektivne-na-mysql-cast-prva-2\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/\",\"name\":\"Websupport blog\",\"description\":\"Websupport blog\",\"publisher\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"sk-SK\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#organization\",\"name\":\"Websupport\",\"url\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"sk-SK\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/app\\\/uploads\\\/sites\\\/2\\\/2021\\\/08\\\/websupport-logo.svg\",\"contentUrl\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/app\\\/uploads\\\/sites\\\/2\\\/2021\\\/08\\\/websupport-logo.svg\",\"width\":153,\"height\":48,\"caption\":\"Websupport\"},\"image\":{\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\"}},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/#\\\/schema\\\/person\\\/cfe2fdf5ce9bfcd4f149370167e2eae5\",\"name\":\"Franti\u0161ek Droj\u00e1k\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"sk-SK\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/05e67bbfc90db9ba65ac2120122339581cadd7636782d642912823802dc16b41?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/05e67bbfc90db9ba65ac2120122339581cadd7636782d642912823802dc16b41?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/05e67bbfc90db9ba65ac2120122339581cadd7636782d642912823802dc16b41?s=96&d=mm&r=g\",\"caption\":\"Franti\u0161ek Droj\u00e1k\"},\"description\":\"Franti\u0161ek pracuje na pozici 2nd line admin.\",\"url\":\"https:\\\/\\\/www.websupport.sk\\\/blog\\\/author\\\/frantisek-drojak\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1 - Websupport blog","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/","og_locale":"sk_SK","og_type":"article","og_title":"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1 - Websupport blog","og_description":"Na admin oddelen\u00ed sa \u010dasto stret\u00e1vame s r\u00f4znymi probl\u00e9mami na\u0161ich z\u00e1kazn\u00edkov, ktor\u00e9 s\u00fa nie v\u017edy chybou na strane samotn\u00e9ho servera a hostingu ako tak\u00e9ho. Preto sme sa rozhodli p\u00edsa\u0165 seri\u00e1l o r\u00f4znych tipoch, ktor\u00e9 by v\u00e1m mali pom\u00f4c\u0165 pochopi\u0165 a odstr\u00e1ni\u0165 niektor\u00e9 probl\u00e9my so str\u00e1nkami. V tejto \u010dasti sa hlavne za\u010dneme venova\u0165 MySQL datab\u00e1zam.","og_url":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/","og_site_name":"Websupport blog","article_published_time":"2013-06-16T19:48:36+00:00","article_modified_time":"2025-03-11T20:06:19+00:00","og_image":[{"width":290,"height":200,"url":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2015\/01\/cervena_4.png","type":"image\/png"}],"author":"Franti\u0161ek Droj\u00e1k","twitter_card":"summary_large_image","twitter_misc":{"Autor":"Franti\u0161ek Droj\u00e1k","Predpokladan\u00fd \u010das \u010d\u00edtania":"4 min\u00faty"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#article","isPartOf":{"@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/"},"author":{"name":"Franti\u0161ek Droj\u00e1k","@id":"https:\/\/www.websupport.sk\/blog\/#\/schema\/person\/cfe2fdf5ce9bfcd4f149370167e2eae5"},"headline":"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1","datePublished":"2013-06-16T19:48:36+00:00","dateModified":"2025-03-11T20:06:19+00:00","mainEntityOfPage":{"@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/"},"wordCount":884,"commentCount":20,"publisher":{"@id":"https:\/\/www.websupport.sk\/blog\/#organization"},"image":{"@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#primaryimage"},"thumbnailUrl":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2015\/01\/cervena_4.png","keywords":["JOIN","MySQL","Rychlost stranok"],"articleSection":["Technol\u00f3gie","Tipy a triky"],"inLanguage":"sk-SK","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/","url":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/","name":"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1 - Websupport blog","isPartOf":{"@id":"https:\/\/www.websupport.sk\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#primaryimage"},"image":{"@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#primaryimage"},"thumbnailUrl":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2015\/01\/cervena_4.png","datePublished":"2013-06-16T19:48:36+00:00","dateModified":"2025-03-11T20:06:19+00:00","breadcrumb":{"@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#breadcrumb"},"inLanguage":"sk-SK","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/"]}]},{"@type":"ImageObject","inLanguage":"sk-SK","@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#primaryimage","url":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2015\/01\/cervena_4.png","contentUrl":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2015\/01\/cervena_4.png","width":290,"height":200},{"@type":"BreadcrumbList","@id":"https:\/\/www.websupport.sk\/blog\/2013\/06\/efektivne-na-mysql-cast-prva-2\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.websupport.sk\/blog\/"},{"@type":"ListItem","position":2,"name":"Efekt\u00edvne na MySQL, \u010das\u0165 prv\u00e1"}]},{"@type":"WebSite","@id":"https:\/\/www.websupport.sk\/blog\/#website","url":"https:\/\/www.websupport.sk\/blog\/","name":"Websupport blog","description":"Websupport blog","publisher":{"@id":"https:\/\/www.websupport.sk\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.websupport.sk\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"sk-SK"},{"@type":"Organization","@id":"https:\/\/www.websupport.sk\/blog\/#organization","name":"Websupport","url":"https:\/\/www.websupport.sk\/blog\/","logo":{"@type":"ImageObject","inLanguage":"sk-SK","@id":"https:\/\/www.websupport.sk\/blog\/#\/schema\/logo\/image\/","url":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2021\/08\/websupport-logo.svg","contentUrl":"https:\/\/www.websupport.sk\/blog\/app\/uploads\/sites\/2\/2021\/08\/websupport-logo.svg","width":153,"height":48,"caption":"Websupport"},"image":{"@id":"https:\/\/www.websupport.sk\/blog\/#\/schema\/logo\/image\/"}},{"@type":"Person","@id":"https:\/\/www.websupport.sk\/blog\/#\/schema\/person\/cfe2fdf5ce9bfcd4f149370167e2eae5","name":"Franti\u0161ek Droj\u00e1k","image":{"@type":"ImageObject","inLanguage":"sk-SK","@id":"https:\/\/secure.gravatar.com\/avatar\/05e67bbfc90db9ba65ac2120122339581cadd7636782d642912823802dc16b41?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/05e67bbfc90db9ba65ac2120122339581cadd7636782d642912823802dc16b41?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/05e67bbfc90db9ba65ac2120122339581cadd7636782d642912823802dc16b41?s=96&d=mm&r=g","caption":"Franti\u0161ek Droj\u00e1k"},"description":"Franti\u0161ek pracuje na pozici 2nd line admin.","url":"https:\/\/www.websupport.sk\/blog\/author\/frantisek-drojak\/"}]}},"_links":{"self":[{"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/posts\/3979","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/users\/33"}],"replies":[{"embeddable":true,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/comments?post=3979"}],"version-history":[{"count":1,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/posts\/3979\/revisions"}],"predecessor-version":[{"id":33621,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/posts\/3979\/revisions\/33621"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/media\/5578"}],"wp:attachment":[{"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/media?parent=3979"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/categories?post=3979"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.websupport.sk\/blog\/wp-json\/wp\/v2\/tags?post=3979"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}