{"id":36816,"date":"2025-12-17T11:50:26","date_gmt":"2025-12-17T04:50:26","guid":{"rendered":"https:\/\/interdata.vn\/blog\/?p=36816"},"modified":"2025-12-17T11:50:54","modified_gmt":"2025-12-17T04:50:54","slug":"index-trong-database-la-gi","status":"publish","type":"post","link":"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/","title":{"rendered":"Index trong Database l\u00e0 g\u00ec? C\u00e1ch ho\u1ea1t \u0111\u1ed9ng, c\u00e1c lo\u1ea1i &#038; \u1ee8ng d\u1ee5ng"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_85 counter-hierarchy ez-toc-counter ez-toc-white ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">N\u1ed8I DUNG<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 eztoc-toggle-hide-by-default' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Index-trong-database-la-gi\" >Index trong database l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Index-trong-database-dung-de-lam-gi\" >Index trong database d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Index-trong-database-hoat-dong-nhu-the-nao\" >Index trong database ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Tai-sao-can-danh-Index-cho-Database\" >T\u1ea1i sao c\u1ea7n \u0111\u00e1nh Index cho Database?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Tang-toc-do-truy-van-SELECT\" >T\u0103ng t\u1ed1c \u0111\u1ed9 truy v\u1ea5n (SELECT)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Toi-uu-cac-tac-vu-sap-xep-ORDER-BY-va-gom-nhom-GROUP-BY\" >T\u1ed1i \u01b0u c\u00e1c t\u00e1c v\u1ee5 s\u1eafp x\u1ebfp (ORDER BY) v\u00e0 gom nh\u00f3m (GROUP BY)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Dam-bao-tinh-toan-ven-du-lieu\" >\u0110\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n d\u1eef li\u1ec7u<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Cac-loai-index-trong-database-pho-bien-hien-nay\" >C\u00e1c lo\u1ea1i index trong database ph\u1ed5 bi\u1ebfn hi\u1ec7n nay<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Clustered-Index-va-Non-Clustered-Index-la-gi\" >Clustered Index v\u00e0 Non-Clustered Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Unique-Index-Composite-Index-Full-text-Index-la-gi\" >Unique Index, Composite Index, Full-text Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Uu-va-nhuoc-diem-cua-tung-loai-index-trong-database\" >\u01afu v\u00e0 nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a t\u1eebng lo\u1ea1i index trong database<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Phan-loai-index-trong-database-dua-tren-cau-truc-du-lieu\" >Ph\u00e2n lo\u1ea1i index trong database d\u1ef1a tr\u00ean c\u1ea5u tr\u00fac d\u1eef li\u1ec7u<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#B-Tree-Index-la-gi\" >B+ Tree Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Hash-Index-la-gi\" >Hash Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Bitmap-Index-la-gi\" >Bitmap Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Sparse-Index-la-gi\" >Sparse Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Mot-so-cau-truc-index-khac-trong-database\" >M\u1ed9t s\u1ed1 c\u1ea5u tr\u00fac index kh\u00e1c trong database<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Phan-loai-index-trong-database-theo-cach-quan-ly\" >Ph\u00e2n lo\u1ea1i index trong database theo c\u00e1ch qu\u1ea3n l\u00fd<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Primary-Index-la-gi\" >Primary Index l\u00e0 g\u00ec?<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Secondary-Index-la-gi\" >Secondary Index l\u00e0 g\u00ec?<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-21\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Uu-va-nhuoc-diem-cua-index-trong-database\" >\u01afu v\u00e0 nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a index trong database<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-22\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Uu-diem\" >\u01afu \u0111i\u1ec3m<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-23\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Nhuoc-diem-va-nhung-lam-tuong\" >Nh\u01b0\u1ee3c \u0111i\u1ec3m v\u00e0 nh\u1eefng l\u1ea7m t\u01b0\u1edfng<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-24\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Khi-nao-nen-va-khong-nen-dung-Index\" >Khi n\u00e0o n\u00ean v\u00e0 kh\u00f4ng n\u00ean d\u00f9ng Index?<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-25\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Truong-hop-NEN-tao-Index\" >Tr\u01b0\u1eddng h\u1ee3p N\u00caN t\u1ea1o Index<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-26\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Truong-hop-KHONG-NEN-tao-Index\" >Tr\u01b0\u1eddng h\u1ee3p KH\u00d4NG N\u00caN t\u1ea1o Index<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-27\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Ung-dung-thuc-te-cua-index-trong-database\" >\u1ee8ng d\u1ee5ng th\u1ef1c t\u1ebf c\u1ee7a index trong database<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-28\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Index-trong-thuong-mai-dien-tu\" >Index trong th\u01b0\u01a1ng m\u1ea1i \u0111i\u1ec7n t\u1eed<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-29\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Index-trong-ngan-hang-va-tai-chinh\" >Index trong ng\u00e2n h\u00e0ng v\u00e0 t\u00e0i ch\u00ednh<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-30\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Index-trong-vien-thong-va-he-thong-du-lieu-lon\" >Index trong vi\u1ec5n th\u00f4ng v\u00e0 h\u1ec7 th\u1ed1ng d\u1eef li\u1ec7u l\u1edbn<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-31\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Vi-du-thuc-te-ve-cach-su-dung-index-trong-database\" >V\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u1ec1 c\u00e1ch s\u1eed d\u1ee5ng index trong database<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-32\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Tao-index-tren-cot-khoa-chinh\" >T\u1ea1o index tr\u00ean c\u1ed9t kh\u00f3a ch\u00ednh<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-33\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Tao-secondary-index-cho-cot-khong-phai-khoa-chinh\" >T\u1ea1o secondary index cho c\u1ed9t kh\u00f4ng ph\u1ea3i kh\u00f3a ch\u00ednh<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-34\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Tao-composite-index-cho-truy-van-nhieu-dieu-kien\" >T\u1ea1o composite index cho truy v\u1ea5n nhi\u1ec1u \u0111i\u1ec1u ki\u1ec7n<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-35\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Tao-filtered-index-cho-mot-tap-du-lieu-cu-the\" >T\u1ea1o filtered index cho m\u1ed9t t\u1eadp d\u1eef li\u1ec7u c\u1ee5 th\u1ec3<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-36\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Su-dung-index-de-toi-uu-truy-van-sap-xep-ORDER-BY\" >S\u1eed d\u1ee5ng index \u0111\u1ec3 t\u1ed1i \u01b0u truy v\u1ea5n s\u1eafp x\u1ebfp (ORDER BY)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-37\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Cac-thao-tac-co-ban-voi-index-trong-database\" >C\u00e1c thao t\u00e1c c\u01a1 b\u1ea3n v\u1edbi index trong database<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-38\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Nhung-luu-y-quan-trong-khi-su-dung-index-trong-database\" >Nh\u1eefng l\u01b0u \u00fd quan tr\u1ecdng khi s\u1eed d\u1ee5ng index trong database<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-39\" href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/#Su-dung-index-trong-database-nhu-the-nao-cho-hieu-qua\" >S\u1eed d\u1ee5ng index trong database nh\u01b0 th\u1ebf n\u00e0o cho hi\u1ec7u qu\u1ea3?<\/a><\/li><\/ul><\/nav><\/div>\n<p>Khi l\u00e0m vi\u1ec7c v\u1edbi c\u01a1 s\u1edf d\u1eef li\u1ec7u, kh\u00f4ng \u00edt ng\u01b0\u1eddi g\u1eb7p t\u00ecnh tr\u1ea1ng truy v\u1ea5n ch\u1eadm, \u0111\u1eb7c bi\u1ec7t l\u00e0 khi d\u1eef li\u1ec7u ng\u00e0y c\u00e0ng l\u1edbn. D\u00f9 c\u00e2u l\u1ec7nh <a href=\"https:\/\/interdata.vn\/blog\/structured-query-language-sql-la-gi\/\">SQL<\/a> kh\u00f4ng ph\u1ee9c t\u1ea1p, th\u1eddi gian ph\u1ea3n h\u1ed3i v\u1eabn k\u00e9o d\u00e0i khi\u1ebfn hi\u1ec7u su\u1ea5t h\u1ec7 th\u1ed1ng b\u1ecb \u1ea3nh h\u01b0\u1edfng. \u0110\u00e2y c\u0169ng l\u00e0 l\u00fac nhi\u1ec1u ng\u01b0\u1eddi b\u1eaft \u0111\u1ea7u th\u1eafc m\u1eafc: index trong database l\u00e0 g\u00ec, v\u00ec sao ch\u1ec9 c\u1ea7n t\u1ea1o index m\u00e0 t\u1ed1c \u0111\u1ed9 truy v\u1ea5n c\u00f3 th\u1ec3 c\u1ea3i thi\u1ec7n r\u00f5 r\u1ec7t?<\/p>\n<p>Trong b\u00e0i vi\u1ebft n\u00e0y, b\u1ea1n s\u1ebd hi\u1ec3u r\u00f5 <strong><a href=\"https:\/\/interdata.vn\/blog\/index-trong-database-la-gi\/\">index trong database l\u00e0 g\u00ec<\/a><\/strong>, c\u00e1ch index ho\u1ea1t \u0111\u1ed9ng, c\u00e1c lo\u1ea1i index trong Database ph\u1ed5 bi\u1ebfn c\u0169ng nh\u01b0 khi n\u00e0o n\u00ean v\u00e0 kh\u00f4ng n\u00ean s\u1eed d\u1ee5ng index \u0111\u1ec3 t\u0103ng t\u1ed1c \u0111\u1ed9 <a href=\"https:\/\/interdata.vn\/blog\/data-preprocessing-la-gi\/\">x\u1eed l\u00fd d\u1eef li\u1ec7u<\/a> l\u00ean m\u1ee9c t\u1ed1i \u0111a.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Index-trong-database-la-gi\"><\/span>Index trong database l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><strong>Index trong database<\/strong> (ch\u1ec9 m\u1ee5c trong c\u01a1 s\u1edf d\u1eef li\u1ec7u) l\u00e0 <strong>m\u1ed9t <a href=\"https:\/\/interdata.vn\/blog\/cau-truc-du-lieu\/\">c\u1ea5u tr\u00fac d\u1eef li\u1ec7u<\/a> \u0111\u1eb7c bi\u1ec7t<\/strong> \u0111\u01b0\u1ee3c t\u1ea1o ra nh\u1eb1m <strong>gi\u00fap <a href=\"https:\/\/interdata.vn\/blog\/he-quan-tri-co-so-du-lieu-la-gi\/\">h\u1ec7 qu\u1ea3n tr\u1ecb c\u01a1 s\u1edf d\u1eef li\u1ec7u<\/a> t\u00ecm v\u00e0 truy xu\u1ea5t d\u1eef li\u1ec7u nhanh h\u01a1n<\/strong>, thay v\u00ec ph\u1ea3i qu\u00e9t to\u00e0n b\u1ed9 b\u1ea3ng.<\/p>\n<p>B\u1ea1n c\u00f3 th\u1ec3 h\u00ecnh dung index gi\u1ed1ng nh\u01b0 <strong>m\u1ee5c l\u1ee5c c\u1ee7a m\u1ed9t cu\u1ed1n s\u00e1ch<\/strong>:<\/p>\n<ul>\n<li>Thay v\u00ec l\u1eadt t\u1eebng trang \u0111\u1ec3 t\u00ecm n\u1ed9i dung c\u1ea7n \u0111\u1ecdc<\/li>\n<li>B\u1ea1n ch\u1ec9 c\u1ea7n tra m\u1ee5c l\u1ee5c \u0111\u1ec3 bi\u1ebft ch\u00ednh x\u00e1c trang ch\u1ee9a th\u00f4ng tin \u0111\u00f3<\/li>\n<\/ul>\n<p>Trong database, index l\u01b0u tr\u1eef <strong>gi\u00e1 tr\u1ecb c\u1ee7a m\u1ed9t ho\u1eb7c nhi\u1ec1u c\u1ed9t<\/strong> c\u00f9ng v\u1edbi <strong>con tr\u1ecf tr\u1ecf \u0111\u1ebfn v\u1ecb tr\u00ed b\u1ea3n ghi t\u01b0\u01a1ng \u1ee9ng<\/strong> trong b\u1ea3ng d\u1eef li\u1ec7u. Khi c\u00f3 truy v\u1ea5n, h\u1ec7 th\u1ed1ng s\u1ebd tra c\u1ee9u trong index tr\u01b0\u1edbc, sau \u0111\u00f3 truy c\u1eadp tr\u1ef1c ti\u1ebfp \u0111\u1ebfn d\u1eef li\u1ec7u c\u1ea7n thi\u1ebft, t\u1eeb \u0111\u00f3 <strong>gi\u1ea3m \u0111\u00e1ng k\u1ec3 th\u1eddi gian x\u1eed l\u00fd truy v\u1ea5n<\/strong>.<\/p>\n<p>Index th\u01b0\u1eddng \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng d\u1ef1a tr\u00ean c\u00e1c c\u1ea5u tr\u00fac nh\u01b0 <strong>B-Tree, B+ <a href=\"https:\/\/interdata.vn\/blog\/cau-truc-du-lieu-tree-cay\/\">Tree<\/a> ho\u1eb7c Hash<\/strong>, v\u00e0 \u0111\u1eb7c bi\u1ec7t hi\u1ec7u qu\u1ea3 v\u1edbi nh\u1eefng b\u1ea3ng c\u00f3 d\u1eef li\u1ec7u l\u1edbn ho\u1eb7c c\u00e1c truy v\u1ea5n th\u01b0\u1eddng xuy\u00ean s\u1eed d\u1ee5ng \u0111i\u1ec1u ki\u1ec7n <strong>WHERE, JOIN, ORDER BY<\/strong>.<\/p>\n<figure id=\"attachment_36817\" aria-describedby=\"caption-attachment-36817\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36817\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Index-trong-database-la-gi.jpg\" alt=\"Index trong database l\u00e0 g\u00ec\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Index-trong-database-la-gi.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Index-trong-database-la-gi-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Index-trong-database-la-gi-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36817\" class=\"wp-caption-text\">Index trong database l\u00e0 g\u00ec?<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Index-trong-database-dung-de-lam-gi\"><\/span>Index trong database d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>R\u1ea5t nhi\u1ec1u <a href=\"https:\/\/interdata.vn\/blog\/lap-trinh-la-gi\/\">l\u1eadp tr\u00ecnh<\/a> vi\u00ean m\u1edbi v\u00e0o ngh\u1ec1 (Fresher\/Junior) th\u01b0\u1eddng th\u1eafc m\u1eafc <strong>index database d\u00f9ng \u0111\u1ec3 l\u00e0m g\u00ec<\/strong> ngo\u00e0i vi\u1ec7c gi\u00fap t\u00ecm ki\u1ebfm nhanh h\u01a1n. Th\u1ef1c t\u1ebf, vai tr\u00f2 c\u1ee7a c\u00f4ng c\u1ee5 n\u00e0y r\u1ed9ng h\u01a1n th\u1ebf nhi\u1ec1u.<\/p>\n<p>M\u1ee5c \u0111\u00edch c\u1ed1t l\u00f5i c\u1ee7a <strong>index trong database<\/strong> l\u00e0 t\u1ed1i \u01b0u h\u00f3a hi\u1ec7u su\u1ea5t \u0111\u1ecdc d\u1eef li\u1ec7u (Read Performance). Khi l\u01b0\u1ee3ng d\u1eef li\u1ec7u trong b\u1ea3ng t\u0103ng l\u00ean h\u00e0ng tr\u0103m ngh\u00ecn hay h\u00e0ng tri\u1ec7u b\u1ea3n ghi (<a href=\"https:\/\/interdata.vn\/blog\/big-data-la-gi\/\">Big Data<\/a>), s\u1ef1 ch\u00eanh l\u1ec7ch v\u1ec1 t\u1ed1c \u0111\u1ed9 gi\u1eefa c\u00f3 index v\u00e0 kh\u00f4ng c\u00f3 index l\u00e0 c\u1ef1c k\u1ef3 l\u1edbn \u2013 c\u00f3 th\u1ec3 l\u00e0 v\u00e0i mili gi\u00e2y so v\u1edbi v\u00e0i ph\u00fat.<\/p>\n<p>C\u1ee5 th\u1ec3, <strong>t\u00e1c d\u1ee5ng c\u1ee7a index trong database<\/strong> bao g\u1ed3m:<\/p>\n<ol>\n<li><strong>Gi\u1ea3m thi\u1ec3u chi ph\u00ed I\/O (Input\/Output):<\/strong> Thay v\u00ec \u0111\u1ecdc h\u00e0ng ngh\u00ecn block d\u1eef li\u1ec7u t\u1eeb \u1ed5 c\u1ee9ng \u0111\u1ec3 t\u00ecm m\u1ed9t d\u00f2ng, database ch\u1ec9 c\u1ea7n \u0111\u1ecdc m\u1ed9t v\u00e0i block c\u1ee7a index. \u0110i\u1ec1u n\u00e0y gi\u1ea3m t\u1ea3i \u00e1p l\u1ef1c r\u1ea5t l\u1edbn cho <a href=\"https:\/\/interdata.vn\/blog\/o-cung-server\/\">\u1ed5 c\u1ee9ng server<\/a>.<\/li>\n<li><strong>H\u1ed7 tr\u1ee3 b\u1ed9 t\u1ed1i \u01b0u h\u00f3a truy v\u1ea5n (<a href=\"https:\/\/interdata.vn\/blog\/query-la-gi\/\">Query<\/a> Optimizer):<\/strong> Khi nh\u1eadn \u0111\u01b0\u1ee3c c\u00e2u l\u1ec7nh SQL, b\u1ed9 t\u1ed1i \u01b0u h\u00f3a s\u1ebd xem x\u00e9t c\u00e1c \u0111\u01b0\u1eddng \u0111i (execution plan). N\u1ebfu th\u1ea5y c\u00f3 index ph\u00f9 h\u1ee3p, h\u1ec7 th\u1ed1ng s\u1ebd ch\u1ecdn \u0111\u01b0\u1eddng \u0111i ng\u1eafn nh\u1ea5t qua index thay v\u00ec \u0111\u01b0\u1eddng \u0111i d\u00e0i qua b\u1ea3ng g\u1ed1c.<\/li>\n<li><strong>Bi\u1ebfn \u0111\u1ed5i c\u00e1ch th\u1ee9c truy xu\u1ea5t:<\/strong> Chuy\u1ec3n \u0111\u1ed5i thao t\u00e1c t\u00ecm ki\u1ebfm t\u1eeb tu\u1ea7n t\u1ef1 (Sequential Scan) sang t\u00ecm ki\u1ebfm nh\u1ecb ph\u00e2n ho\u1eb7c t\u00ecm ki\u1ebfm theo c\u00e2y (Tree Traversal), gi\u00fap gi\u1ea3m \u0111\u1ed9 ph\u1ee9c t\u1ea1p <a href=\"https:\/\/interdata.vn\/blog\/thuat-toan-algorithm\/\">thu\u1eadt to\u00e1n<\/a>.<\/li>\n<\/ol>\n<p>Hi\u1ec3u r\u00f5 <strong>t\u1ea1i sao c\u1ea7n index trong database<\/strong> s\u1ebd gi\u00fap b\u1ea1n thi\u1ebft k\u1ebf h\u1ec7 th\u1ed1ng c\u00f3 kh\u1ea3 n\u0103ng m\u1edf r\u1ed9ng (Scalability) t\u1ed1t h\u01a1n. M\u1ed9t database \u0111\u01b0\u1ee3c \u0111\u00e1nh index t\u1ed1t v\u1eabn s\u1ebd ch\u1ea1y m\u01b0\u1ee3t m\u00e0 khi d\u1eef li\u1ec7u ph\u00ecnh to, trong khi m\u1ed9t database thi\u1ebfu index s\u1ebd nhanh ch\u00f3ng b\u1ecb &#8220;treo&#8221; khi s\u1ed1 l\u01b0\u1ee3ng ng\u01b0\u1eddi d\u00f9ng t\u0103ng l\u00ean.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Index-trong-database-hoat-dong-nhu-the-nao\"><\/span>Index trong database ho\u1ea1t \u0111\u1ed9ng nh\u01b0 th\u1ebf n\u00e0o?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Index trong database v\u1eadn h\u00e0nh d\u1ef1a tr\u00ean c\u00e1c c\u1ea5u tr\u00fac d\u1eef li\u1ec7u nh\u01b0 <strong>B-Tree<\/strong>,<strong> B+ Tree<\/strong> ho\u1eb7c <strong><a href=\"https:\/\/interdata.vn\/blog\/hash-table-la-gi\/\">Hash Table<\/a><\/strong>, gi\u00fap x\u00e1c \u0111\u1ecbnh v\u1ecb tr\u00ed d\u1eef li\u1ec7u nhanh v\u00e0 ch\u00ednh x\u00e1c h\u01a1n. Khi m\u1ed9t truy v\u1ea5n \u0111\u01b0\u1ee3c th\u1ef1c thi, h\u1ec7 qu\u1ea3n tr\u1ecb c\u01a1 s\u1edf d\u1eef li\u1ec7u s\u1ebd kh\u00f4ng qu\u00e9t to\u00e0n b\u1ed9 b\u1ea3ng d\u1eef li\u1ec7u. Thay v\u00e0o \u0111\u00f3, h\u1ec7 th\u1ed1ng tra c\u1ee9u th\u00f4ng tin trong b\u1ea3ng index tr\u01b0\u1edbc \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u1ecba ch\u1ec9 c\u1ee7a b\u1ea3n ghi c\u1ea7n t\u00ecm, r\u1ed3i truy c\u1eadp tr\u1ef1c ti\u1ebfp \u0111\u1ebfn d\u1eef li\u1ec7u t\u01b0\u01a1ng \u1ee9ng trong b\u1ea3ng g\u1ed1c.<\/p>\n<p>V\u00ed d\u1ee5: Khi c\u1ea7n t\u00ecm th\u00f4ng tin kh\u00e1ch h\u00e0ng theo s\u1ed1 \u0111i\u1ec7n tho\u1ea1i, h\u1ec7 th\u1ed1ng s\u1ebd tra c\u1ee9u trong index \u0111\u00e3 \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp theo s\u1ed1 \u0111i\u1ec7n tho\u1ea1i thay v\u00ec duy\u1ec7t to\u00e0n b\u1ed9 danh s\u00e1ch. Nh\u1edd v\u1eady, t\u1ed1c \u0111\u1ed9 truy v\u1ea5n c\u00f3 th\u1ec3 nhanh h\u01a1n g\u1ea5p nhi\u1ec1u l\u1ea7n so v\u1edbi c\u00e1ch t\u00ecm ki\u1ebfm th\u00f4ng th\u01b0\u1eddng.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Tai-sao-can-danh-Index-cho-Database\"><\/span>T\u1ea1i sao c\u1ea7n \u0111\u00e1nh Index cho Database?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Vi\u1ec7c \u0111\u00e1nh index kh\u00f4ng ch\u1ec9 l\u00e0 m\u1ed9t l\u1ef1a ch\u1ecdn &#8220;cho vui&#8221;, m\u00e0 l\u00e0 y\u00eau c\u1ea7u b\u1eaft bu\u1ed9c \u0111\u1ed1i v\u1edbi b\u1ea5t k\u1ef3 h\u1ec7 th\u1ed1ng ph\u1ea7n m\u1ec1m chuy\u00ean nghi\u1ec7p n\u00e0o. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 nh\u1eefng l\u00fd do chi ti\u1ebft gi\u1ea3i th\u00edch <strong>t\u1ea1i sao c\u1ea7n \u0111\u00e1nh index<\/strong> v\u00e0 nh\u1eefng l\u1ee3i \u00edch thi\u1ebft th\u1ef1c m\u00e0 k\u1ef9 thu\u1eadt n\u00e0y mang l\u1ea1i.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Tang-toc-do-truy-van-SELECT\"><\/span>T\u0103ng t\u1ed1c \u0111\u1ed9 truy v\u1ea5n (SELECT)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u00e2y l\u00e0 l\u1ee3i \u00edch r\u00f5 r\u00e0ng nh\u1ea5t. <strong>T\u00e1c d\u1ee5ng c\u1ee7a index<\/strong> th\u1ec3 hi\u1ec7n m\u1ea1nh m\u1ebd nh\u1ea5t trong c\u00e1c c\u00e2u l\u1ec7nh SELECT c\u00f3 m\u1ec7nh \u0111\u1ec1 WHERE.<\/p>\n<p>V\u00ed d\u1ee5, b\u1ea1n c\u00f3 b\u1ea3ng KhachHang v\u1edbi 1 tri\u1ec7u d\u00f2ng v\u00e0 c\u1ea7n t\u00ecm kh\u00e1ch h\u00e0ng c\u00f3 s\u1ed1 \u0111i\u1ec7n tho\u1ea1i &#8220;0987654321&#8221;.<\/p>\n<ul>\n<li>N\u1ebfu c\u1ed9t SoDienThoai kh\u00f4ng c\u00f3 index: Database ph\u1ea3i so s\u00e1nh 1 tri\u1ec7u l\u1ea7n.<\/li>\n<li>N\u1ebfu c\u1ed9t SoDienThoai c\u00f3 index: Database ch\u1ec9 c\u1ea7n th\u1ef1c hi\u1ec7n kho\u1ea3ng 20-30 ph\u00e9p so s\u00e1nh tr\u00ean c\u00e2y B-Tree \u0111\u1ec3 t\u00ecm ra k\u1ebft qu\u1ea3.<\/li>\n<\/ul>\n<p>Vi\u1ec7c n\u00e0y gi\u00fap <strong>t\u1ed1i \u01b0u query<\/strong>, gi\u1ea3m th\u1eddi gian ch\u1edd \u0111\u1ee3i c\u1ee7a ng\u01b0\u1eddi d\u00f9ng cu\u1ed1i (End-user) v\u00e0 n\u00e2ng cao tr\u1ea3i nghi\u1ec7m kh\u00e1ch h\u00e0ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Toi-uu-cac-tac-vu-sap-xep-ORDER-BY-va-gom-nhom-GROUP-BY\"><\/span>T\u1ed1i \u01b0u c\u00e1c t\u00e1c v\u1ee5 s\u1eafp x\u1ebfp (ORDER BY) v\u00e0 gom nh\u00f3m (GROUP BY)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Khi b\u1ea1n th\u1ef1c hi\u1ec7n c\u00e2u l\u1ec7nh SQL c\u00f3 ORDER BY ho\u1eb7c GROUP BY, database th\u01b0\u1eddng ph\u1ea3i gom to\u00e0n b\u1ed9 d\u1eef li\u1ec7u v\u00e0o b\u1ed9 nh\u1edb t\u1ea1m (Buffer) \u0111\u1ec3 th\u1ef1c hi\u1ec7n s\u1eafp x\u1ebfp. Qu\u00e1 tr\u00ecnh n\u00e0y ti\u00eau t\u1ed1n r\u1ea5t nhi\u1ec1u CPU v\u00e0 <a href=\"https:\/\/interdata.vn\/blog\/ram-server\/\">RAM<\/a>.<\/p>\n<p>N\u1ebfu c\u1ed9t \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp \u0111\u00e3 c\u00f3 index, d\u1eef li\u1ec7u trong index v\u1ed1n d\u0129 \u0111\u00e3 \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp s\u1eb5n theo th\u1ee9 t\u1ef1 (v\u00ed d\u1ee5 A-Z ho\u1eb7c t\u0103ng d\u1ea7n). Do \u0111\u00f3, database c\u00f3 th\u1ec3 l\u1ea5y d\u1eef li\u1ec7u tr\u1ef1c ti\u1ebfp t\u1eeb index m\u00e0 kh\u00f4ng c\u1ea7n t\u1ed1n t\u00e0i nguy\u00ean \u0111\u1ec3 s\u1eafp x\u1ebfp l\u1ea1i. \u0110\u00e2y l\u00e0 m\u1ed9t b\u00ed quy\u1ebft <strong>t\u1ed1i \u01b0u database b\u1eb1ng index<\/strong> m\u00e0 c\u00e1c Senior Developer th\u01b0\u1eddng \u00e1p d\u1ee5ng \u0111\u1ec3 gi\u1ea3m t\u1ea3i cho <a href=\"https:\/\/interdata.vn\/blog\/cpu-server\/\">CPU server<\/a>.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Dam-bao-tinh-toan-ven-du-lieu\"><\/span>\u0110\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n d\u1eef li\u1ec7u<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ngo\u00e0i vi\u1ec7c t\u0103ng t\u1ed1c \u0111\u1ed9, m\u1ed9t d\u1ea1ng index \u0111\u1eb7c bi\u1ec7t l\u00e0 <strong>Unique Index<\/strong> c\u00f2n \u0111\u00f3ng vai tr\u00f2 nh\u01b0 m\u1ed9t ch\u1ed1t ch\u1eb7n b\u1ea3o v\u1ec7 d\u1eef li\u1ec7u. Khi b\u1ea1n \u0111\u00e1nh Unique Index cho m\u1ed9t c\u1ed9t (v\u00ed d\u1ee5: Email ho\u1eb7c SoCCCD), database s\u1ebd t\u1ef1 \u0111\u1ed9ng ki\u1ec3m tra v\u00e0 ng\u0103n ch\u1eb7n b\u1ea5t k\u1ef3 h\u00e0nh \u0111\u1ed9ng n\u00e0o c\u1ed1 t\u00ecnh ch\u00e8n d\u1eef li\u1ec7u tr\u00f9ng l\u1eb7p v\u00e0o c\u1ed9t \u0111\u00f3. \u0110i\u1ec1u n\u00e0y \u0111\u1ea3m b\u1ea3o t\u00ednh nh\u1ea5t qu\u00e1n v\u00e0 ch\u00ednh x\u00e1c cho h\u1ec7 th\u1ed1ng th\u00f4ng tin c\u1ee7a b\u1ea1n.<\/p>\n<article>\n<h2><span class=\"ez-toc-section\" id=\"Cac-loai-index-trong-database-pho-bien-hien-nay\"><\/span>C\u00e1c lo\u1ea1i index trong database ph\u1ed5 bi\u1ebfn hi\u1ec7n nay<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Trong h\u1ec7 th\u1ed1ng c\u01a1 s\u1edf d\u1eef li\u1ec7u, index kh\u00f4ng ch\u1ec9 t\u1ed3n t\u1ea1i d\u01b0\u1edbi m\u1ed9t d\u1ea1ng duy nh\u1ea5t m\u00e0 \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng v\u1edbi nhi\u1ec1u h\u00ecnh th\u1ee9c kh\u00e1c nhau \u0111\u1ec3 \u0111\u00e1p \u1ee9ng t\u1eebng nhu c\u1ea7u s\u1eed d\u1ee5ng c\u1ee5 th\u1ec3. M\u1ed7i lo\u1ea1i index \u0111\u1ec1u c\u00f3 \u0111i\u1ec3m m\u1ea1nh v\u00e0 h\u1ea1n ch\u1ebf ri\u00eang, ph\u00f9 h\u1ee3p v\u1edbi t\u1eebng ki\u1ec3u truy v\u1ea5n ho\u1eb7c c\u1ea5u tr\u00fac d\u1eef li\u1ec7u nh\u1ea5t \u0111\u1ecbnh.<\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 c\u00e1c lo\u1ea1i index trong Database ph\u1ed5 bi\u1ebfn.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Clustered-Index-va-Non-Clustered-Index-la-gi\"><\/span>Clustered Index v\u00e0 Non-Clustered Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Clustered Index<\/strong> l\u00e0 lo\u1ea1i index quy\u1ebft \u0111\u1ecbnh c\u00e1ch d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp v\u1eadt l\u00fd b\u00ean trong b\u1ea3ng d\u1ef1a tr\u00ean c\u1ed9t \u0111\u01b0\u1ee3c ch\u1ecdn l\u00e0m ch\u1ec9 m\u1ee5c. Do d\u1eef li\u1ec7u ch\u1ec9 c\u00f3 th\u1ec3 s\u1eafp x\u1ebfp theo m\u1ed9t tr\u1eadt t\u1ef1 duy nh\u1ea5t, n\u00ean m\u1ed7i b\u1ea3ng ch\u1ec9 \u0111\u01b0\u1ee3c ph\u00e9p c\u00f3 m\u1ed9t clustered index. Lo\u1ea1i index n\u00e0y \u0111\u1eb7c bi\u1ec7t ph\u00e1t huy hi\u1ec7u qu\u1ea3 khi truy v\u1ea5n theo kho\u1ea3ng gi\u00e1 tr\u1ecb ho\u1eb7c khi c\u1ea7n s\u1eafp x\u1ebfp d\u1eef li\u1ec7u theo th\u1ee9 t\u1ef1.<\/p>\n<p>Ng\u01b0\u1ee3c l\u1ea1i, <strong>Non-Clustered Index<\/strong> kh\u00f4ng l\u00e0m thay \u0111\u1ed5i th\u1ee9 t\u1ef1 l\u01b0u tr\u1eef d\u1eef li\u1ec7u trong b\u1ea3ng. Thay v\u00e0o \u0111\u00f3, n\u00f3 t\u1ea1o ra m\u1ed9t c\u1ea5u tr\u00fac ri\u00eang, l\u01b0u tr\u1eef gi\u00e1 tr\u1ecb kh\u00f3a k\u00e8m theo con tr\u1ecf tr\u1ecf \u0111\u1ebfn v\u1ecb tr\u00ed t\u01b0\u01a1ng \u1ee9ng c\u1ee7a b\u1ea3n ghi. M\u1ed9t b\u1ea3ng c\u00f3 th\u1ec3 s\u1edf h\u1eefu nhi\u1ec1u non-clustered index, gi\u00fap t\u1ed1i \u01b0u t\u1ed1t c\u00e1c truy v\u1ea5n t\u00ecm ki\u1ebfm tr\u00ean nhi\u1ec1u c\u1ed9t kh\u00e1c nhau.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Unique-Index-Composite-Index-Full-text-Index-la-gi\"><\/span>Unique Index, Composite Index, Full-text Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Unique Index<\/strong> c\u00f3 nhi\u1ec7m v\u1ee5 \u0111\u1ea3m b\u1ea3o r\u1eb1ng c\u00e1c gi\u00e1 tr\u1ecb trong c\u1ed9t ho\u1eb7c nh\u00f3m c\u1ed9t \u0111\u01b0\u1ee3c \u0111\u00e1nh index l\u00e0 kh\u00f4ng tr\u00f9ng l\u1eb7p. Lo\u1ea1i index n\u00e0y th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng cho c\u00e1c tr\u01b0\u1eddng nh\u01b0 email, username hay s\u1ed1 CMND nh\u1eb1m ng\u0103n ch\u1eb7n d\u1eef li\u1ec7u b\u1ecb l\u1eb7p.<\/p>\n<p><strong>Composite Index<\/strong> l\u00e0 ch\u1ec9 m\u1ee5c \u0111\u01b0\u1ee3c t\u1ea1o t\u1eeb hai ho\u1eb7c nhi\u1ec1u c\u1ed9t trong c\u00f9ng m\u1ed9t b\u1ea3ng. \u0110\u00e2y l\u00e0 l\u1ef1a ch\u1ecdn ph\u00f9 h\u1ee3p khi c\u00e1c truy v\u1ea5n th\u01b0\u1eddng xuy\u00ean s\u1eed d\u1ee5ng \u0111i\u1ec1u ki\u1ec7n k\u1ebft h\u1ee3p nhi\u1ec1u c\u1ed9t, gi\u00fap c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t r\u00f5 r\u1ec7t so v\u1edbi vi\u1ec7c t\u1ea1o nhi\u1ec1u index \u0111\u01a1n l\u1ebb.<\/p>\n<p><strong>Full-text Index<\/strong> \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 ph\u1ee5c v\u1ee5 nhu c\u1ea7u t\u00ecm ki\u1ebfm to\u00e0n v\u0103n, \u0111\u1eb7c bi\u1ec7t hi\u1ec7u qu\u1ea3 v\u1edbi c\u00e1c c\u1ed9t ch\u1ee9a v\u0103n b\u1ea3n d\u00e0i nh\u01b0 n\u1ed9i dung b\u00e0i vi\u1ebft ho\u1eb7c m\u00f4 t\u1ea3 s\u1ea3n ph\u1ea9m. C\u00e1c h\u1ec7 qu\u1ea3n tr\u1ecb database nh\u01b0 <a href=\"https:\/\/interdata.vn\/blog\/mysql-la-gi\/\">MySQL<\/a> hay SQL <a href=\"https:\/\/interdata.vn\/blog\/may-chu-server-la-gi\/\">Server<\/a> h\u1ed7 tr\u1ee3 full-text index, cho ph\u00e9p t\u00ecm ki\u1ebfm theo t\u1eeb kh\u00f3a, c\u1ee5m t\u1eeb v\u00e0 \u00e1p d\u1ee5ng c\u00e1c b\u1ed9 l\u1ecdc n\u00e2ng cao.<\/p>\n<figure id=\"attachment_36818\" aria-describedby=\"caption-attachment-36818\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36818\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loai-index-trong-database.jpg\" alt=\"C\u00e1c lo\u1ea1i index trong database\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loai-index-trong-database.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loai-index-trong-database-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Cac-loai-index-trong-database-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36818\" class=\"wp-caption-text\">C\u00e1c lo\u1ea1i index trong database<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Uu-va-nhuoc-diem-cua-tung-loai-index-trong-database\"><\/span>\u01afu v\u00e0 nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a t\u1eebng lo\u1ea1i index trong database<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>M\u1ed7i lo\u1ea1i index \u0111\u1ec1u mang l\u1ea1i l\u1ee3i \u00edch nh\u1ea5t \u0111\u1ecbnh nh\u01b0ng c\u0169ng t\u1ed3n t\u1ea1i nh\u1eefng h\u1ea1n ch\u1ebf ri\u00eang, t\u00f9y thu\u1ed9c v\u00e0o b\u1ed1i c\u1ea3nh s\u1eed d\u1ee5ng:<\/p>\n<ul>\n<li><strong>Clustered Index<\/strong> gi\u00fap t\u0103ng t\u1ed1c truy v\u1ea5n khi l\u1ecdc v\u00e0 s\u1eafp x\u1ebfp theo th\u1ee9 t\u1ef1, nh\u01b0ng m\u1ed7i b\u1ea3ng ch\u1ec9 c\u00f3 th\u1ec3 t\u1ea1o duy nh\u1ea5t m\u1ed9t clustered index.<\/li>\n<li><strong>Non-Clustered Index<\/strong> linh ho\u1ea1t h\u01a1n v\u1ec1 s\u1ed1 l\u01b0\u1ee3ng, tuy nhi\u00ean s\u1ebd ti\u00eau t\u1ed1n th\u00eam kh\u00f4ng gian l\u01b0u tr\u1eef v\u00e0 c\u1ea7n \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt khi d\u1eef li\u1ec7u thay \u0111\u1ed5i.<\/li>\n<li><strong>Unique Index<\/strong> \u0111\u1ea3m b\u1ea3o t\u00ednh to\u00e0n v\u1eb9n d\u1eef li\u1ec7u, nh\u01b0ng n\u1ebfu s\u1eed d\u1ee5ng qu\u00e1 nhi\u1ec1u c\u00f3 th\u1ec3 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn t\u1ed1c \u0111\u1ed9 ghi d\u1eef li\u1ec7u.<\/li>\n<li><strong>Composite Index<\/strong> t\u1ed1i \u01b0u t\u1ed1t cho c\u00e1c truy v\u1ea5n nhi\u1ec1u c\u1ed9t, song ch\u1ec9 ph\u00e1t huy hi\u1ec7u qu\u1ea3 khi \u0111i\u1ec1u ki\u1ec7n truy v\u1ea5n ph\u00f9 h\u1ee3p v\u1edbi th\u1ee9 t\u1ef1 c\u00e1c c\u1ed9t trong index.<\/li>\n<li><strong>Full-text Index<\/strong> r\u1ea5t m\u1ea1nh khi x\u1eed l\u00fd d\u1eef li\u1ec7u v\u0103n b\u1ea3n d\u00e0i, nh\u01b0ng y\u00eau c\u1ea7u dung l\u01b0\u1ee3ng l\u01b0u tr\u1eef l\u1edbn h\u01a1n v\u00e0 c\u1ea7n c\u1ea5u h\u00ecnh b\u1ed5 sung.<\/li>\n<\/ul>\n<p>Vi\u1ec7c hi\u1ec3u r\u00f5 \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a t\u1eebng lo\u1ea1i index v\u00e0 \u00e1p d\u1ee5ng \u0111\u00fang tr\u01b0\u1eddng h\u1ee3p s\u1ebd gi\u00fap h\u1ec7 th\u1ed1ng c\u01a1 s\u1edf d\u1eef li\u1ec7u v\u1eadn h\u00e0nh hi\u1ec7u qu\u1ea3 v\u00e0 \u1ed5n \u0111\u1ecbnh h\u01a1n.<\/p>\n<\/article>\n<article>\n<div>\n<div>\n<h2><span class=\"ez-toc-section\" id=\"Phan-loai-index-trong-database-dua-tren-cau-truc-du-lieu\"><\/span>Ph\u00e2n lo\u1ea1i index trong database d\u1ef1a tr\u00ean c\u1ea5u tr\u00fac d\u1eef li\u1ec7u<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Trong c\u01a1 s\u1edf d\u1eef li\u1ec7u, index \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng tr\u00ean nhi\u1ec1u c\u1ea5u tr\u00fac d\u1eef li\u1ec7u kh\u00e1c nhau nh\u1eb1m ph\u1ee5c v\u1ee5 c\u00e1c nhu c\u1ea7u truy v\u1ea5n ri\u00eang bi\u1ec7t. M\u1ed9t s\u1ed1 c\u1ea5u tr\u00fac index ph\u1ed5 bi\u1ebfn th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng bao g\u1ed3m:<\/p>\n<h3><span class=\"ez-toc-section\" id=\"B-Tree-Index-la-gi\"><\/span>B+ Tree Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>B+ Tree l\u00e0 m\u1ed9t trong nh\u1eefng c\u1ea5u tr\u00fac index \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng r\u1ed9ng r\u00e3i nh\u1ea5t hi\u1ec7n nay. \u0110\u00e2y l\u00e0 c\u1ea5u tr\u00fac t\u1ef1 c\u00e2n b\u1eb1ng, trong \u0111\u00f3 c\u00e1c n\u00fat l\u00e1 l\u01b0u tr\u1eef con tr\u1ecf tr\u1ecf \u0111\u1ebfn d\u1eef li\u1ec7u th\u1ef1c t\u1ebf. M\u1ed7i n\u00fat c\u00f3 th\u1ec3 ch\u1ee9a nhi\u1ec1u kh\u00f3a c\u00f9ng v\u1edbi c\u00e1c con tr\u1ecf li\u00ean k\u1ebft \u0111\u1ebfn c\u00e1c n\u00fat con, gi\u00fap t\u1ed1i \u01b0u hi\u1ec7u qu\u1ea3 cho c\u00e1c truy v\u1ea5n theo ph\u1ea1m vi (range queries).<\/p>\n<p>Nh\u1edd \u0111\u1eb7c \u0111i\u1ec3m n\u00e0y, vi\u1ec7c t\u00ecm ki\u1ebfm, th\u00eam m\u1edbi v\u00e0 x\u00f3a d\u1eef li\u1ec7u \u0111\u1ec1u di\u1ec5n ra hi\u1ec7u qu\u1ea3, khi\u1ebfn B+ Tree index ph\u00f9 h\u1ee3p v\u1edbi h\u1ea7u h\u1ebft c\u00e1c h\u1ec7 qu\u1ea3n tr\u1ecb c\u01a1 s\u1edf d\u1eef li\u1ec7u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Hash-Index-la-gi\"><\/span>Hash Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Hash index s\u1eed d\u1ee5ng h\u00e0m b\u0103m \u0111\u1ec3 \u00e1nh x\u1ea1 kh\u00f3a \u0111\u1ebfn m\u1ed9t v\u1ecb tr\u00ed l\u01b0u tr\u1eef x\u00e1c \u0111\u1ecbnh trong ch\u1ec9 m\u1ee5c. Lo\u1ea1i index n\u00e0y cho t\u1ed1c \u0111\u1ed9 r\u1ea5t nhanh khi x\u1eed l\u00fd c\u00e1c truy v\u1ea5n t\u00ecm ki\u1ebfm kh\u1edbp ch\u00ednh x\u00e1c b\u1eb1ng to\u00e1n t\u1eed b\u1eb1ng (=).<\/p>\n<p>Tuy nhi\u00ean, hash index kh\u00f4ng ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c truy v\u1ea5n theo ph\u1ea1m vi nh\u01b0 l\u1edbn h\u01a1n, nh\u1ecf h\u01a1n hay BETWEEN. V\u00ec \u0111\u1eb7c th\u00f9 \u0111\u00f3, hash index th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng trong c\u00e1c c\u01a1 s\u1edf d\u1eef li\u1ec7u ch\u1ea1y tr\u00ean b\u1ed9 nh\u1edb ho\u1eb7c \u0111\u01b0\u1ee3c d\u00f9ng nh\u01b0 m\u1ed9t ch\u1ec9 m\u1ee5c ph\u1ee5.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Bitmap-Index-la-gi\"><\/span>Bitmap Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Bitmap index th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng cho nh\u1eefng c\u1ed9t c\u00f3 \u0111\u1ed9 ph\u00e2n bi\u1ec7t th\u1ea5p, t\u1ee9c l\u00e0 ch\u1ec9 ch\u1ee9a m\u1ed9t s\u1ed1 l\u01b0\u1ee3ng gi\u00e1 tr\u1ecb kh\u00e1c nhau h\u1ea1n ch\u1ebf. Lo\u1ea1i index n\u00e0y \u0111\u1eb7c bi\u1ec7t hi\u1ec7u qu\u1ea3 trong c\u00e1c truy v\u1ea5n ph\u1ee9c t\u1ea1p v\u00e0 c\u00e1c h\u1ec7 th\u1ed1ng c\u00f3 kh\u1ed1i l\u01b0\u1ee3ng truy v\u1ea5n \u0111\u1ecdc l\u1edbn. Ng\u01b0\u1ee3c l\u1ea1i, bitmap index kh\u00f4ng ph\u00f9 h\u1ee3p v\u1edbi c\u00e1c m\u00f4i tr\u01b0\u1eddng c\u00f3 t\u1ea7n su\u1ea5t ghi d\u1eef li\u1ec7u cao do hi\u1ec7u su\u1ea5t c\u1eadp nh\u1eadt kh\u00f4ng t\u1ed1i \u01b0u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Sparse-Index-la-gi\"><\/span>Sparse Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Sparse index kh\u00f4ng l\u01b0u tr\u1eef th\u00f4ng tin index cho to\u00e0n b\u1ed9 c\u00e1c d\u00f2ng d\u1eef li\u1ec7u trong b\u1ea3ng m\u00e0 ch\u1ec9 t\u1eadp trung v\u00e0o m\u1ed9t t\u1eadp con nh\u1ea5t \u0111\u1ecbnh. C\u00e1ch ti\u1ebfp c\u1eadn n\u00e0y gi\u00fap gi\u1ea3m dung l\u01b0\u1ee3ng l\u01b0u tr\u1eef v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t truy v\u1ea5n trong nh\u1eefng tr\u01b0\u1eddng h\u1ee3p kh\u00f4ng c\u1ea7n \u0111\u00e1nh index cho to\u00e0n b\u1ed9 d\u1eef li\u1ec7u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Mot-so-cau-truc-index-khac-trong-database\"><\/span>M\u1ed9t s\u1ed1 c\u1ea5u tr\u00fac index kh\u00e1c trong database<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>B\u00ean c\u1ea1nh c\u00e1c lo\u1ea1i index k\u1ec3 tr\u00ean, c\u00f2n t\u1ed3n t\u1ea1i nhi\u1ec1u c\u1ea5u tr\u00fac index kh\u00e1c nh\u01b0 LSM Tree, GiST, GIN, R-Tree hay SSTable, \u0111\u01b0\u1ee3c thi\u1ebft k\u1ebf \u0111\u1ec3 ph\u1ee5c v\u1ee5 nh\u1eefng k\u1ecbch b\u1ea3n s\u1eed d\u1ee5ng v\u00e0 lo\u1ea1i d\u1eef li\u1ec7u kh\u00e1c nhau.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Phan-loai-index-trong-database-theo-cach-quan-ly\"><\/span>Ph\u00e2n lo\u1ea1i index trong database theo c\u00e1ch qu\u1ea3n l\u00fd<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>C\u00e1ch ph\u00e2n lo\u1ea1i n\u00e0y d\u1ef1a tr\u00ean ph\u01b0\u01a1ng th\u1ee9c m\u00e0 index \u0111\u01b0\u1ee3c qu\u1ea3n l\u00fd v\u00e0 \u00e1p d\u1ee5ng trong h\u1ec7 qu\u1ea3n tr\u1ecb c\u01a1 s\u1edf d\u1eef li\u1ec7u.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Primary-Index-la-gi\"><\/span>Primary Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Primary index l\u00e0 ch\u1ec9 m\u1ee5c \u0111\u01b0\u1ee3c t\u1ea1o tr\u00ean c\u1ed9t <a href=\"https:\/\/interdata.vn\/blog\/khoa-chinh-la-gi\/\">kh\u00f3a ch\u00ednh<\/a> (primary key) c\u1ee7a b\u1ea3ng. Lo\u1ea1i index n\u00e0y gi\u00fap \u0111\u1ea3m b\u1ea3o m\u1ed7i b\u1ea3n ghi trong b\u1ea3ng l\u00e0 duy nh\u1ea5t, \u0111\u1ed3ng th\u1eddi t\u0103ng t\u1ed1c \u0111\u1ed9 t\u00ecm ki\u1ebfm d\u1ef1a tr\u00ean c\u1ed9t kh\u00f3a ch\u00ednh.<\/p>\n<p>Trong nhi\u1ec1u h\u1ec7 qu\u1ea3n tr\u1ecb c\u01a1 s\u1edf d\u1eef li\u1ec7u, primary index th\u01b0\u1eddng \u0111\u00f3ng vai tr\u00f2 l\u00e0 clustered index, t\u1ee9c l\u00e0 d\u1eef li\u1ec7u trong b\u1ea3ng \u0111\u01b0\u1ee3c s\u1eafp x\u1ebfp v\u1eadt l\u00fd theo gi\u00e1 tr\u1ecb c\u1ee7a kh\u00f3a ch\u00ednh. V\u00ed d\u1ee5, v\u1edbi b\u1ea3ng <code>employees<\/code>, khi s\u1eed d\u1ee5ng primary index tr\u00ean c\u1ed9t <code>employee_id<\/code>, h\u1ec7 th\u1ed1ng v\u1eeba \u0111\u1ea3m b\u1ea3o t\u00ednh duy nh\u1ea5t c\u1ee7a m\u1ed7i b\u1ea3n ghi, v\u1eeba gi\u00fap c\u00e1c truy v\u1ea5n t\u00ecm ki\u1ebfm theo <code>employee_id<\/code> \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n nhanh h\u01a1n.<\/p>\n<figure id=\"attachment_36822\" aria-describedby=\"caption-attachment-36822\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36822\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Phan-loai-index-trong-database.jpg\" alt=\"Ph\u00e2n lo\u1ea1i index trong database\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Phan-loai-index-trong-database.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Phan-loai-index-trong-database-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Phan-loai-index-trong-database-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36822\" class=\"wp-caption-text\">Ph\u00e2n lo\u1ea1i index trong database<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Secondary-Index-la-gi\"><\/span>Secondary Index l\u00e0 g\u00ec?<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Secondary index l\u00e0 ch\u1ec9 m\u1ee5c \u0111\u01b0\u1ee3c t\u1ea1o tr\u00ean c\u00e1c c\u1ed9t kh\u00f4ng ph\u1ea3i kh\u00f3a ch\u00ednh nh\u1eb1m c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t t\u00ecm ki\u1ebfm tr\u00ean nh\u1eefng c\u1ed9t n\u00e0y. Lo\u1ea1i index n\u00e0y \u0111\u1eb7c bi\u1ec7t h\u1eefu \u00edch khi c\u1ea7n t\u1ed1i \u01b0u c\u00e1c truy v\u1ea5n li\u00ean quan \u0111\u1ebfn nhi\u1ec1u c\u1ed9t kh\u00e1c ngo\u00e0i kh\u00f3a ch\u00ednh.<\/p>\n<p>Secondary index th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng cho nh\u1eefng c\u1ed9t kh\u00f4ng ph\u1ea3i kh\u00f3a ch\u00ednh nh\u01b0ng xu\u1ea5t hi\u1ec7n th\u01b0\u1eddng xuy\u00ean trong \u0111i\u1ec1u ki\u1ec7n truy v\u1ea5n. Ch\u1eb3ng h\u1ea1n, trong b\u1ea3ng <code>customers<\/code>, n\u1ebfu c\u00e1c truy v\u1ea5n th\u01b0\u1eddng d\u1ef1a tr\u00ean c\u1ed9t <code>phone_number<\/code> thay v\u00ec kh\u00f3a ch\u00ednh, vi\u1ec7c t\u1ea1o secondary index cho c\u1ed9t n\u00e0y s\u1ebd gi\u00fap t\u0103ng \u0111\u00e1ng k\u1ec3 t\u1ed1c \u0111\u1ed9 truy v\u1ea5n.<\/p>\n<\/div>\n<\/div>\n<\/article>\n<h2><span class=\"ez-toc-section\" id=\"Uu-va-nhuoc-diem-cua-index-trong-database\"><\/span>\u01afu v\u00e0 nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a index trong database<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Trong k\u1ef9 thu\u1eadt ph\u1ea7n m\u1ec1m, kh\u00f4ng c\u00f3 gi\u1ea3i ph\u00e1p n\u00e0o l\u00e0 ho\u00e0n h\u1ea3o tuy\u1ec7t \u0111\u1ed1i (No Silver Bullet). Index c\u0169ng v\u1eady. Vi\u1ec7c s\u1eed d\u1ee5ng <strong>index trong database<\/strong> lu\u00f4n \u0111i k\u00e8m v\u1edbi s\u1ef1 \u0111\u00e1nh \u0111\u1ed5i (Trade-off). B\u1ea1n c\u1ea7n n\u1eafm r\u00f5 <strong>\u01b0u nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a index trong database<\/strong> \u0111\u1ec3 \u0111\u01b0a ra quy\u1ebft \u0111\u1ecbnh ch\u00ednh x\u00e1c.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Uu-diem\"><\/span>\u01afu \u0111i\u1ec3m<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>T\u1ed1c \u0111\u1ed9 \u0111\u1ecdc v\u01b0\u1ee3t tr\u1ed9i:<\/strong> Nh\u01b0 \u0111\u00e3 ph\u00e2n t\u00edch, index gi\u00fap c\u00e1c c\u00e2u l\u1ec7nh SELECT ch\u1ea1y nhanh g\u1ea5p h\u00e0ng tr\u0103m, h\u00e0ng ngh\u00ecn l\u1ea7n.<\/li>\n<li><strong>Hi\u1ec7u su\u1ea5t h\u1ec7 th\u1ed1ng cao:<\/strong> Gi\u1ea3m t\u1ea3i CPU v\u00e0 I\/O \u0111\u0129a, cho ph\u00e9p server ph\u1ee5c v\u1ee5 nhi\u1ec1u ng\u01b0\u1eddi d\u00f9ng c\u00f9ng l\u00fac h\u01a1n.<\/li>\n<li><strong>T\u00ecm ki\u1ebfm th\u00f4ng minh:<\/strong> H\u1ed7 tr\u1ee3 t\u1ed1t cho c\u00e1c truy v\u1ea5n t\u00ecm ki\u1ebfm g\u1ea7n \u0111\u00fang (Range Query) ho\u1eb7c t\u00ecm ki\u1ebfm ch\u00ednh x\u00e1c.<\/li>\n<\/ul>\n<h3><span class=\"ez-toc-section\" id=\"Nhuoc-diem-va-nhung-lam-tuong\"><\/span>Nh\u01b0\u1ee3c \u0111i\u1ec3m v\u00e0 nh\u1eefng l\u1ea7m t\u01b0\u1edfng<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>R\u1ea5t nhi\u1ec1u b\u1ea1n m\u1edbi th\u01b0\u1eddng c\u00f3 suy ngh\u0129 sai l\u1ea7m: &#8220;Index t\u1ed1t v\u1eady th\u00ec c\u1ee9 \u0111\u00e1nh index cho t\u1ea5t c\u1ea3 c\u00e1c c\u1ed9t l\u00e0 xong&#8221;. T\u01b0 duy n\u00e0y c\u1ef1c k\u1ef3 nguy hi\u1ec3m v\u00ec nh\u1eefng nh\u01b0\u1ee3c \u0111i\u1ec3m sau:<\/p>\n<ol>\n<li><strong>T\u1ed1n dung l\u01b0\u1ee3ng l\u01b0u tr\u1eef (Chi ph\u00ed l\u01b0u tr\u1eef index):<\/strong> Index l\u00e0 m\u1ed9t c\u1ea5u tr\u00fac d\u1eef li\u1ec7u, v\u00e0 c\u1ea5u tr\u00fac n\u00e0y c\u1ea7n kh\u00f4ng gian \u0111\u1ec3 l\u01b0u tr\u1eef tr\u00ean \u1ed5 c\u1ee9ng v\u00e0 RAM. V\u1edbi c\u00e1c b\u1ea3ng l\u1edbn, dung l\u01b0\u1ee3ng c\u1ee7a index c\u00f3 th\u1ec3 chi\u1ebfm t\u1edbi 30-40% dung l\u01b0\u1ee3ng c\u1ee7a ch\u00ednh b\u1ea3ng d\u1eef li\u1ec7u \u0111\u00f3. N\u1ebfu b\u1ea1n \u0111\u00e1nh index v\u00f4 t\u1ed9i v\u1ea1, database s\u1ebd ph\u00ecnh to nhanh ch\u00f3ng, g\u00e2y t\u1ed1n k\u00e9m chi ph\u00ed h\u1ea1 t\u1ea7ng.<\/li>\n<li><strong>L\u00e0m ch\u1eadm thao t\u00e1c ghi (INSERT, UPDATE, DELETE):<\/strong> \u0110\u00e2y l\u00e0 n\u1ed7i \u0111au l\u1edbn nh\u1ea5t &#8211; <strong>index l\u00e0m ch\u1eadm thao t\u00e1c ghi<\/strong>. M\u1ed7i khi b\u1ea1n th\u00eam m\u1edbi (Insert), s\u1eeda (Update) ho\u1eb7c x\u00f3a (Delete) m\u1ed9t d\u00f2ng d\u1eef li\u1ec7u, database kh\u00f4ng ch\u1ec9 c\u1eadp nh\u1eadt b\u1ea3ng ch\u00ednh m\u00e0 c\u00f2n ph\u1ea3i c\u1eadp nh\u1eadt l\u1ea1i t\u1ea5t c\u1ea3 c\u00e1c index li\u00ean quan. H\u1ec7 th\u1ed1ng ph\u1ea3i t\u1ed1n th\u1eddi gian \u0111\u1ec3 c\u00e2n b\u1eb1ng l\u1ea1i c\u00e2y B-Tree, s\u1eafp x\u1ebfp l\u1ea1i v\u1ecb tr\u00ed c\u00e1c n\u00fat. C\u00e0ng nhi\u1ec1u index, thao t\u00e1c ghi c\u00e0ng ch\u1eadm.<\/li>\n<\/ol>\n<p><strong>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf:<\/strong> N\u1ebfu b\u1ea3ng c\u1ee7a b\u1ea1n c\u00f3 5 index, khi b\u1ea1n Insert 1 d\u00f2ng, database th\u1ef1c ch\u1ea5t ph\u1ea3i th\u1ef1c hi\u1ec7n 6 thao t\u00e1c ghi (1 cho b\u1ea3ng ch\u00ednh + 5 cho index). Do \u0111\u00f3, v\u1edbi c\u00e1c h\u1ec7 th\u1ed1ng c\u1ea7n ghi d\u1eef li\u1ec7u li\u00ean t\u1ee5c (nh\u01b0 Log h\u1ec7 th\u1ed1ng, Sensor data), vi\u1ec7c d\u00f9ng index c\u1ea7n h\u1ebft s\u1ee9c th\u1eadn tr\u1ecdng.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Khi-nao-nen-va-khong-nen-dung-Index\"><\/span>Khi n\u00e0o n\u00ean v\u00e0 kh\u00f4ng n\u00ean d\u00f9ng Index?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>\u0110\u1ec3 tr\u1edf th\u00e0nh m\u1ed9t chuy\u00ean gia t\u1ed1i \u01b0u h\u00f3a, b\u1ea1n kh\u00f4ng ch\u1ec9 c\u1ea7n bi\u1ebft <strong>index trong database l\u00e0 g\u00ec<\/strong>, m\u00e0 c\u00f2n ph\u1ea3i bi\u1ebft ngh\u1ec7 thu\u1eadt s\u1eed d\u1ee5ng ch\u00fang \u0111\u00fang l\u00fac, \u0111\u00fang ch\u1ed7. D\u01b0\u1edbi \u0111\u00e2y l\u00e0 b\u1ed9 quy t\u1eafc &#8220;v\u00e0ng&#8221; (Best Practices) t\u1eeb kinh nghi\u1ec7m th\u1ef1c chi\u1ebfn c\u1ee7a \u0111\u1ed9i ng\u0169 k\u1ef9 thu\u1eadt InterData.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Truong-hop-NEN-tao-Index\"><\/span>Tr\u01b0\u1eddng h\u1ee3p N\u00caN t\u1ea1o Index<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>B\u1ea1n h\u00e3y \u01b0u ti\u00ean \u0111\u00e1nh index cho c\u00e1c c\u1ed9t th\u1ecfa m\u00e3n c\u00e1c \u0111i\u1ec1u ki\u1ec7n sau:<\/p>\n<ol>\n<li><strong>C\u1ed9t l\u00e0 Kh\u00f3a ch\u00ednh (Primary Key) v\u00e0 Kh\u00f3a ngo\u1ea1i (<a href=\"https:\/\/interdata.vn\/blog\/foreign-key-la-gi\/\">Foreign Key<\/a>):<\/strong> \u0110\u00e2y l\u00e0 \u0111i\u1ec1u b\u1eaft bu\u1ed9c. Kh\u00f3a ch\u00ednh gi\u00fap \u0111\u1ecbnh danh b\u1ea3n ghi, c\u00f2n kh\u00f3a ngo\u1ea1i th\u01b0\u1eddng xuy\u00ean \u0111\u01b0\u1ee3c d\u00f9ng trong c\u00e1c ph\u00e9p JOIN gi\u1eefa c\u00e1c b\u1ea3ng. Index s\u1ebd gi\u00fap thao t\u00e1c JOIN di\u1ec5n ra nhanh ch\u00f3ng.<\/li>\n<li><strong>C\u1ed9t th\u01b0\u1eddng xuy\u00ean xu\u1ea5t hi\u1ec7n trong m\u1ec7nh \u0111\u1ec1 WHERE:<\/strong> N\u1ebfu b\u1ea1n hay l\u1ecdc d\u1eef li\u1ec7u theo m\u1ed9t tr\u01b0\u1eddng n\u00e0o \u0111\u00f3 (v\u00ed d\u1ee5: WHERE Status = &#8216;Active&#8217; ho\u1eb7c WHERE UserID = 123), h\u00e3y \u0111\u00e1nh index cho c\u1ed9t \u0111\u00f3.<\/li>\n<li><strong>C\u1ed9t th\u01b0\u1eddng xuy\u00ean d\u00f9ng \u0111\u1ec3 s\u1eafp x\u1ebfp (ORDER BY):<\/strong> Nh\u01b0 \u0111\u00e3 \u0111\u1ec1 c\u1eadp, index gi\u00fap b\u1ecf qua b\u01b0\u1edbc sorting t\u1ed1n k\u00e9m t\u00e0i nguy\u00ean.<\/li>\n<li><strong>C\u1ed9t c\u00f3 \u0111\u1ed9 ch\u1ecdn l\u1ecdc cao (High Selectivity):<\/strong> \u0110\u1ed9 ch\u1ecdn l\u1ecdc l\u00e0 t\u1ec9 l\u1ec7 c\u00e1c gi\u00e1 tr\u1ecb duy nh\u1ea5t trong c\u1ed9t. C\u1ed9t c\u00f3 nhi\u1ec1u gi\u00e1 tr\u1ecb kh\u00e1c nhau (nh\u01b0 S\u1ed1 \u0111i\u1ec7n tho\u1ea1i, Email, M\u00e3 \u0111\u01a1n h\u00e0ng) l\u00e0 \u1ee9ng c\u1eed vi\u00ean s\u00e1ng gi\u00e1 cho index.<\/li>\n<\/ol>\n<p>Bi\u1ebft <strong>c\u00e1ch t\u1ed1i \u01b0u database b\u1eb1ng index<\/strong> th\u00f4ng qua vi\u1ec7c ch\u1ecdn \u0111\u00fang c\u1ed9t s\u1ebd gi\u00fap h\u1ec7 th\u1ed1ng c\u1ee7a b\u1ea1n ho\u1ea1t \u0111\u1ed9ng tr\u01a1n tru ngay c\u1ea3 khi d\u1eef li\u1ec7u \u0111\u1ea1t ng\u01b0\u1ee1ng tri\u1ec7u d\u00f2ng.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Truong-hop-KHONG-NEN-tao-Index\"><\/span>Tr\u01b0\u1eddng h\u1ee3p KH\u00d4NG N\u00caN t\u1ea1o Index<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Ng\u01b0\u1ee3c l\u1ea1i, b\u1ea1n n\u00ean tr\u00e1nh ho\u1eb7c x\u00f3a b\u1ecf index trong c\u00e1c tr\u01b0\u1eddng h\u1ee3p sau \u0111\u1ec3 kh\u00f4ng l\u00e0m h\u1ec7 th\u1ed1ng b\u1ecb &#8220;\u00ec \u1ea1ch&#8221;:<\/p>\n<ol>\n<li><strong>B\u1ea3ng qu\u00e1 nh\u1ecf:<\/strong> N\u1ebfu b\u1ea3ng ch\u1ec9 c\u00f3 v\u00e0i ch\u1ee5c ho\u1eb7c v\u00e0i tr\u0103m d\u00f2ng, vi\u1ec7c \u0111\u1ecdc index c\u00f3 khi c\u00f2n ch\u1eadm h\u01a1n l\u00e0 qu\u00e9t th\u1eb3ng to\u00e0n b\u1ed9 b\u1ea3ng (do chi ph\u00ed nh\u1ea3y qua l\u1ea1i gi\u1eefa index v\u00e0 data).<\/li>\n<li><strong>C\u1ed9t \u0111\u01b0\u1ee3c c\u1eadp nh\u1eadt qu\u00e1 th\u01b0\u1eddng xuy\u00ean:<\/strong> N\u1ebfu c\u1ed9t d\u1eef li\u1ec7u thay \u0111\u1ed5i li\u00ean t\u1ee5c, chi ph\u00ed \u0111\u1ec3 b\u1ea3o tr\u00ec index s\u1ebd r\u1ea5t l\u1edbn, l\u00e0m ch\u1eadm to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng.<\/li>\n<li><strong>C\u1ed9t c\u00f3 \u0111\u1ed9 ph\u00e2n gi\u1ea3i th\u1ea5p (Low Cardinality):<\/strong> \u0110\u00e2y l\u00e0 sai l\u1ea7m ph\u1ed5 bi\u1ebfn nh\u1ea5t. Khi c\u1ed9t ch\u1ee9a r\u1ea5t \u00edt gi\u00e1 tr\u1ecb duy nh\u1ea5t.\n<ul>\n<li>V\u00ed d\u1ee5: C\u1ed9t GioiTinh ch\u1ec9 c\u00f3 &#8220;Nam&#8221; ho\u1eb7c &#8220;Nu&#8221;. N\u1ebfu b\u1ea1n \u0111\u00e1nh index \u1edf \u0111\u00e2y, database v\u1eabn ph\u1ea3i qu\u00e9t qua 50% d\u1eef li\u1ec7u c\u1ee7a b\u1ea3ng \u0111\u1ec3 l\u1ea5y k\u1ebft qu\u1ea3. Index l\u00fac n\u00e0y g\u1ea7n nh\u01b0 v\u00f4 d\u1ee5ng.<\/li>\n<li>T\u01b0\u01a1ng t\u1ef1 v\u1edbi c\u00e1c c\u1ed9t TrangThai (Active\/Inactive) hay IsDeleted (True\/False).<\/li>\n<\/ul>\n<\/li>\n<li><strong>C\u1ed9t <a href=\"https:\/\/interdata.vn\/blog\/kieu-du-lieu-data-type\/\">ki\u1ec3u d\u1eef li\u1ec7u<\/a> l\u1edbn:<\/strong> H\u1ea1n ch\u1ebf \u0111\u00e1nh index tr\u00ean c\u00e1c c\u1ed9t TEXT, NTEXT ho\u1eb7c VARCHAR(MAX) v\u00ec k\u00edch th\u01b0\u1edbc index s\u1ebd r\u1ea5t l\u1edbn, t\u1ed1n b\u1ed9 nh\u1edb.<\/li>\n<\/ol>\n<article>\n<h2><span class=\"ez-toc-section\" id=\"Ung-dung-thuc-te-cua-index-trong-database\"><\/span>\u1ee8ng d\u1ee5ng th\u1ef1c t\u1ebf c\u1ee7a index trong database<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Index-trong-thuong-mai-dien-tu\"><\/span>Index trong th\u01b0\u01a1ng m\u1ea1i \u0111i\u1ec7n t\u1eed<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>T\u1ea1i c\u00e1c n\u1ec1n t\u1ea3ng th\u01b0\u01a1ng m\u1ea1i \u0111i\u1ec7n t\u1eed nh\u01b0 Shopee, Lazada hay Tiki, h\u1ec7 th\u1ed1ng ph\u1ea3i x\u1eed l\u00fd h\u00e0ng tri\u1ec7u truy v\u1ea5n m\u1ed7i gi\u00e2y, t\u1eeb t\u00ecm ki\u1ebfm s\u1ea3n ph\u1ea9m, l\u1ecdc theo gi\u00e1 v\u00e0 th\u01b0\u01a1ng hi\u1ec7u cho \u0111\u1ebfn s\u1eafp x\u1ebfp theo m\u1ee9c \u0111\u1ed9 ph\u1ed5 bi\u1ebfn. Index gi\u00fap c\u00e1c thao t\u00e1c n\u00e0y di\u1ec5n ra nhanh ch\u00f3ng b\u1eb1ng c\u00e1ch l\u01b0u tr\u1eef nh\u1eefng c\u1ed9t quan tr\u1ecdng nh\u01b0 t\u00ean s\u1ea3n ph\u1ea9m, m\u1ee9c gi\u00e1 ho\u1eb7c danh m\u1ee5c trong c\u00e1c c\u1ea5u tr\u00fac d\u1eef li\u1ec7u t\u1ed1i \u01b0u.<\/p>\n<p>Thay v\u00ec qu\u00e9t to\u00e0n b\u1ed9 b\u1ea3ng v\u1edbi h\u00e0ng tri\u1ec7u b\u1ea3n ghi, h\u1ec7 th\u1ed1ng ch\u1ec9 c\u1ea7n truy c\u1eadp \u0111\u00fang khu v\u1ef1c ch\u1ee9a d\u1eef li\u1ec7u c\u1ea7n thi\u1ebft. Nh\u1edd \u0111\u00f3, ng\u01b0\u1eddi d\u00f9ng nh\u1eadn \u0111\u01b0\u1ee3c k\u1ebft qu\u1ea3 g\u1ea7n nh\u01b0 t\u1ee9c th\u00ec, tr\u1ea3i nghi\u1ec7m t\u00ecm ki\u1ebfm m\u01b0\u1ee3t m\u00e0 h\u01a1n v\u00e0 t\u1ef7 l\u1ec7 r\u1eddi trang \u0111\u01b0\u1ee3c gi\u1ea3m \u0111\u00e1ng k\u1ec3.<\/p>\n<h3><span class=\"ez-toc-section\" id=\"Index-trong-ngan-hang-va-tai-chinh\"><\/span>Index trong ng\u00e2n h\u00e0ng v\u00e0 t\u00e0i ch\u00ednh<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong l\u0129nh v\u1ef1c t\u00e0i ch\u00ednh \u2013 ng\u00e2n h\u00e0ng, t\u1ed1c \u0111\u1ed9 truy xu\u1ea5t d\u1eef li\u1ec7u \u1ea3nh h\u01b0\u1edfng tr\u1ef1c ti\u1ebfp \u0111\u1ebfn hi\u1ec7u qu\u1ea3 v\u1eadn h\u00e0nh h\u1ec7 th\u1ed1ng. C\u00e1c d\u1ecbch v\u1ee5 nh\u01b0 <a href=\"https:\/\/interdata.vn\/blog\/mang-internet\/\">Internet<\/a> Banking hay Mobile Banking li\u00ean t\u1ee5c th\u1ef1c hi\u1ec7n vi\u1ec7c tra c\u1ee9u th\u00f4ng tin kh\u00e1ch h\u00e0ng, ki\u1ec3m tra s\u1ed1 d\u01b0, xem l\u1ecbch s\u1eed giao d\u1ecbch v\u00e0 x\u1eed l\u00fd h\u00e0ng tr\u0103m ngh\u00ecn y\u00eau c\u1ea7u c\u00f9ng l\u00fac. Index gi\u00fap c\u00e1c b\u1ea3ng d\u1eef li\u1ec7u l\u1edbn \u0111\u01b0\u1ee3c truy v\u1ea5n nhanh m\u00e0 kh\u00f4ng g\u00e2y t\u1eafc ngh\u1ebdn h\u1ec7 th\u1ed1ng.<\/p>\n<p><strong>V\u00ed d\u1ee5:<\/strong> Khi ng\u01b0\u1eddi d\u00f9ng tra c\u1ee9u l\u1ecbch s\u1eed giao d\u1ecbch trong v\u00f2ng 3 th\u00e1ng g\u1ea7n nh\u1ea5t, h\u1ec7 th\u1ed1ng s\u1ebd d\u1ef1a v\u00e0o index tr\u00ean c\u00e1c c\u1ed9t <strong>Account ID<\/strong> v\u00e0 <strong>Transaction Date<\/strong> \u0111\u1ec3 l\u1ecdc d\u1eef li\u1ec7u ch\u1ec9 trong v\u00e0i ph\u1ea7n ngh\u00ecn gi\u00e2y, \u0111\u1ea3m b\u1ea3o giao d\u1ecbch th\u1eddi gian th\u1ef1c v\u00e0 \u0111\u1ed9 tin c\u1eady cao.<\/p>\n<figure id=\"attachment_36820\" aria-describedby=\"caption-attachment-36820\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36820\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Ung-dung-thuc-te-cua-index-trong-database.jpg\" alt=\"\u1ee8ng d\u1ee5ng th\u1ef1c t\u1ebf c\u1ee7a index trong database\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Ung-dung-thuc-te-cua-index-trong-database.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Ung-dung-thuc-te-cua-index-trong-database-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Ung-dung-thuc-te-cua-index-trong-database-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36820\" class=\"wp-caption-text\">\u1ee8ng d\u1ee5ng th\u1ef1c t\u1ebf c\u1ee7a index trong database<\/figcaption><\/figure>\n<h3><span class=\"ez-toc-section\" id=\"Index-trong-vien-thong-va-he-thong-du-lieu-lon\"><\/span>Index trong vi\u1ec5n th\u00f4ng v\u00e0 h\u1ec7 th\u1ed1ng d\u1eef li\u1ec7u l\u1edbn<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong ng\u00e0nh vi\u1ec5n th\u00f4ng, d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c t\u1ea1o ra li\u00ean t\u1ee5c v\u1edbi kh\u1ed1i l\u01b0\u1ee3ng c\u1ef1c l\u1edbn, bao g\u1ed3m th\u00f4ng tin thu\u00ea bao, nh\u1eadt k\u00fd cu\u1ed9c g\u1ecdi, d\u1eef li\u1ec7u truy c\u1eadp m\u1ea1ng v\u00e0 h\u00e0ng t\u1ef7 b\u1ea3n ghi log m\u1ed7i ng\u00e0y. C\u00e1c doanh nghi\u1ec7p nh\u01b0 Viettel s\u1eed d\u1ee5ng index \u0111\u1ec3 t\u1ed5 ch\u1ee9c v\u00e0 t\u1ed1i \u01b0u c\u00e1c b\u1ea3ng d\u1eef li\u1ec7u n\u00e0y, gi\u00fap truy xu\u1ea5t nhanh c\u00e1c th\u00f4ng tin nh\u01b0 s\u1ed1 l\u1ea7n g\u1ecdi, th\u1eddi l\u01b0\u1ee3ng cu\u1ed9c g\u1ecdi, v\u1ecb tr\u00ed ho\u1eb7c tr\u1ea1ng th\u00e1i thu\u00ea bao.<\/p>\n<p><strong>V\u00ed d\u1ee5:<\/strong> Khi b\u1ed9 ph\u1eadn k\u1ef9 thu\u1eadt c\u1ea7n x\u00e1c \u0111\u1ecbnh nguy\u00ean nh\u00e2n ngh\u1ebdn m\u1ea1ng t\u1ea1i m\u1ed9t khu v\u1ef1c c\u1ee5 th\u1ec3, index tr\u00ean c\u00e1c tr\u01b0\u1eddng <strong>CellID<\/strong>, <strong>Timestamp<\/strong> v\u00e0 <strong>CallStatus<\/strong> cho ph\u00e9p l\u1ecdc d\u1eef li\u1ec7u ch\u1ec9 trong v\u00e0i gi\u00e2y, thay v\u00ec ph\u1ea3i m\u1ea5t h\u00e0ng gi\u1edd qu\u00e9t to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng.<\/p>\n<h2><span class=\"ez-toc-section\" id=\"Vi-du-thuc-te-ve-cach-su-dung-index-trong-database\"><\/span>V\u00ed d\u1ee5 th\u1ef1c t\u1ebf v\u1ec1 c\u00e1ch s\u1eed d\u1ee5ng index trong database<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<h3><span class=\"ez-toc-section\" id=\"Tao-index-tren-cot-khoa-chinh\"><\/span>T\u1ea1o index tr\u00ean c\u1ed9t kh\u00f3a ch\u00ednh<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong nhi\u1ec1u h\u1ec7 qu\u1ea3n tr\u1ecb c\u01a1 s\u1edf d\u1eef li\u1ec7u, <strong>clustered index<\/strong> th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng cho c\u1ed9t kh\u00f3a ch\u00ednh c\u1ee7a b\u1ea3ng. Ch\u1eb3ng h\u1ea1n, v\u1edbi b\u1ea3ng <code>employees<\/code>, n\u1ebfu b\u1ea1n mu\u1ed1n \u0111\u1ea3m b\u1ea3o m\u1ed7i b\u1ea3n ghi l\u00e0 duy nh\u1ea5t \u0111\u1ed3ng th\u1eddi t\u0103ng t\u1ed1c \u0111\u1ed9 truy v\u1ea5n theo <code>employee_id<\/code>, b\u1ea1n c\u00f3 th\u1ec3 t\u1ea1o index nh\u01b0 sau:<\/p>\n<pre><code>CREATE INDEX idx_employee_id ON employees (employee_id);\r\n<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Tao-secondary-index-cho-cot-khong-phai-khoa-chinh\"><\/span>T\u1ea1o secondary index cho c\u1ed9t kh\u00f4ng ph\u1ea3i kh\u00f3a ch\u00ednh<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><strong>Secondary index<\/strong> \u0111\u01b0\u1ee3c d\u00f9ng \u0111\u1ec3 c\u1ea3i thi\u1ec7n t\u1ed1c \u0111\u1ed9 t\u00ecm ki\u1ebfm tr\u00ean c\u00e1c c\u1ed9t kh\u00f4ng ph\u1ea3i l\u00e0 kh\u00f3a ch\u00ednh. V\u00ed d\u1ee5, trong b\u1ea3ng <code>customers<\/code>, n\u1ebfu c\u00e1c truy v\u1ea5n th\u01b0\u1eddng xuy\u00ean d\u1ef1a tr\u00ean c\u1ed9t <code>phone_number<\/code>, b\u1ea1n c\u00f3 th\u1ec3 t\u1ea1o secondary index b\u1eb1ng c\u00fa ph\u00e1p sau:<\/p>\n<pre><code>CREATE INDEX idx_customer_phone ON customers (phone_number);\r\n<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Tao-composite-index-cho-truy-van-nhieu-dieu-kien\"><\/span>T\u1ea1o composite index cho truy v\u1ea5n nhi\u1ec1u \u0111i\u1ec1u ki\u1ec7n<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Khi c\u1ea7n t\u1ed1i \u01b0u c\u00e1c truy v\u1ea5n s\u1eed d\u1ee5ng nhi\u1ec1u \u0111i\u1ec1u ki\u1ec7n k\u1ebft h\u1ee3p, <strong>composite index<\/strong> l\u00e0 l\u1ef1a ch\u1ecdn ph\u00f9 h\u1ee3p. V\u00ed d\u1ee5, \u0111\u1ec3 t\u0103ng t\u1ed1c \u0111\u1ed9 t\u00ecm ki\u1ebfm theo c\u1ea3 <code>Name<\/code> v\u00e0 <code>Age<\/code> trong b\u1ea3ng <code>Students<\/code>, b\u1ea1n c\u00f3 th\u1ec3 t\u1ea1o index nh\u01b0 sau:<\/p>\n<pre><code>CREATE INDEX idx_students_name_age ON Students (Name, Age);\r\n<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Tao-filtered-index-cho-mot-tap-du-lieu-cu-the\"><\/span>T\u1ea1o filtered index cho m\u1ed9t t\u1eadp d\u1eef li\u1ec7u c\u1ee5 th\u1ec3<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>Trong tr\u01b0\u1eddng h\u1ee3p ch\u1ec9 c\u1ea7n \u0111\u00e1nh index cho m\u1ed9t ph\u1ea7n d\u1eef li\u1ec7u trong b\u1ea3ng, b\u1ea1n c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng <strong>filtered index<\/strong>. V\u00ed d\u1ee5, \u0111\u1ec3 t\u1ea1o index cho c\u00e1c sinh vi\u00ean tr\u00ean 18 tu\u1ed5i trong b\u1ea3ng <code>Students<\/code>, c\u00fa ph\u00e1p s\u1ebd nh\u01b0 sau:<\/p>\n<pre><code>CREATE INDEX idx_students_age_filtered ON Students (Age) WHERE Age &gt; 18;\r\n<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Su-dung-index-de-toi-uu-truy-van-sap-xep-ORDER-BY\"><\/span>S\u1eed d\u1ee5ng index \u0111\u1ec3 t\u1ed1i \u01b0u truy v\u1ea5n s\u1eafp x\u1ebfp (ORDER BY)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p>\u0110\u1ed1i v\u1edbi c\u00e1c truy v\u1ea5n c\u00f3 y\u00eau c\u1ea7u s\u1eafp x\u1ebfp d\u1eef li\u1ec7u b\u1eb1ng m\u1ec7nh \u0111\u1ec1 <code>ORDER BY<\/code>, vi\u1ec7c t\u1ea1o index tr\u00ean c\u1ed9t d\u00f9ng \u0111\u1ec3 s\u1eafp x\u1ebfp s\u1ebd gi\u00fap c\u1ea3i thi\u1ec7n \u0111\u00e1ng k\u1ec3 t\u1ed1c \u0111\u1ed9 truy v\u1ea5n. V\u00ed d\u1ee5:<\/p>\n<pre><code>CREATE INDEX idx_students_order ON Students (Age);\r\n<\/code><\/pre>\n<h3><span class=\"ez-toc-section\" id=\"Cac-thao-tac-co-ban-voi-index-trong-database\"><\/span>C\u00e1c thao t\u00e1c c\u01a1 b\u1ea3n v\u1edbi index trong database<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ul>\n<li><strong>X\u00f3a index:<\/strong> Khi m\u1ed9t index kh\u00f4ng c\u00f2n c\u1ea7n thi\u1ebft, b\u1ea1n c\u00f3 th\u1ec3 lo\u1ea1i b\u1ecf b\u1eb1ng l\u1ec7nh sau:<\/li>\n<\/ul>\n<pre><code>DROP INDEX idx_students_name ON Students;\r\n<\/code><\/pre>\n<ul>\n<li><strong>Th\u00eam index:<\/strong> B\u1ea1n c\u0169ng c\u00f3 th\u1ec3 b\u1ed5 sung index cho m\u1ed9t b\u1ea3ng \u0111\u00e3 t\u1ed3n t\u1ea1i th\u00f4ng qua l\u1ec7nh <code>ALTER TABLE<\/code>:<\/li>\n<\/ul>\n<pre><code>ALTER TABLE Students ADD INDEX idx_students_name (Name);\r\n<\/code><\/pre>\n<h2><span class=\"ez-toc-section\" id=\"Nhung-luu-y-quan-trong-khi-su-dung-index-trong-database\"><\/span>Nh\u1eefng l\u01b0u \u00fd quan tr\u1ecdng khi s\u1eed d\u1ee5ng index trong database<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>Khi \u00e1p d\u1ee5ng index trong c\u01a1 s\u1edf d\u1eef li\u1ec7u, c\u00f3 m\u1ed9t s\u1ed1 \u0111i\u1ec3m quan tr\u1ecdng c\u1ea7n c\u00e2n nh\u1eafc \u0111\u1ec3 t\u1ed1i \u01b0u hi\u1ec7u su\u1ea5t truy v\u1ea5n v\u00e0 qu\u1ea3n l\u00fd t\u00e0i nguy\u00ean hi\u1ec7u qu\u1ea3:<\/p>\n<ul>\n<li><strong>Kh\u00f4ng n\u00ean d\u00f9ng index cho b\u1ea3ng c\u00f3 k\u00edch th\u01b0\u1edbc nh\u1ecf:<\/strong> Vi\u1ec7c t\u1ea1o index cho c\u00e1c b\u1ea3ng nh\u1ecf th\u01b0\u1eddng kh\u00f4ng mang l\u1ea1i l\u1ee3i \u00edch r\u00f5 r\u1ec7t, trong khi chi ph\u00ed qu\u1ea3n l\u00fd index c\u00f3 th\u1ec3 l\u1edbn h\u01a1n l\u1ee3i \u00edch thu \u0111\u01b0\u1ee3c.<\/li>\n<li><strong>Tr\u00e1nh index tr\u00ean c\u00e1c c\u1ed9t thay \u0111\u1ed5i th\u01b0\u1eddng xuy\u00ean:<\/strong> V\u1edbi nh\u1eefng c\u1ed9t c\u00f3 t\u1ea7n su\u1ea5t c\u1eadp nh\u1eadt ho\u1eb7c ch\u00e8n d\u1eef li\u1ec7u cao, index c\u00f3 th\u1ec3 l\u00e0m gi\u1ea3m hi\u1ec7u su\u1ea5t do ph\u1ea3i li\u00ean t\u1ee5c c\u1eadp nh\u1eadt l\u1ea1i ch\u1ec9 m\u1ee5c.<\/li>\n<li><strong>\u01afu ti\u00ean c\u00e1c c\u1ed9t c\u00f3 gi\u00e1 tr\u1ecb ph\u00e2n bi\u1ec7t cao:<\/strong> Index k\u00e9m hi\u1ec7u qu\u1ea3 tr\u00ean nh\u1eefng c\u1ed9t c\u00f3 nhi\u1ec1u gi\u00e1 tr\u1ecb tr\u00f9ng l\u1eb7p ho\u1eb7c ch\u1ee9a nhi\u1ec1u gi\u00e1 tr\u1ecb NULL. V\u00ed d\u1ee5, c\u00e1c c\u1ed9t ch\u1ec9 c\u00f3 hai gi\u00e1 tr\u1ecb nh\u01b0 \u201cNam\u201d v\u00e0 \u201cN\u1eef\u201d th\u01b0\u1eddng kh\u00f4ng mang l\u1ea1i l\u1ee3i \u00edch \u0111\u00e1ng k\u1ec3 khi t\u1ea1o index.<\/li>\n<li><strong>T\u1ea1o index cho c\u00e1c c\u1ed9t hay xu\u1ea5t hi\u1ec7n trong WHERE, JOIN v\u00e0 ORDER BY:<\/strong> Nh\u1eefng c\u1ed9t th\u01b0\u1eddng xuy\u00ean \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng trong c\u00e1c m\u1ec7nh \u0111\u1ec1 n\u00e0y l\u00e0 \u1ee9ng vi\u00ean ph\u00f9 h\u1ee3p \u0111\u1ec3 \u0111\u00e1nh index nh\u1eb1m c\u1ea3i thi\u1ec7n t\u1ed1c \u0111\u1ed9 truy v\u1ea5n.<\/li>\n<li><strong>Gi\u1edbi h\u1ea1n s\u1ed1 l\u01b0\u1ee3ng c\u1ed9t trong index:<\/strong> Khi t\u1ea1o index tr\u00ean nhi\u1ec1u c\u1ed9t, c\u1ea7n s\u1eafp x\u1ebfp th\u1ee9 t\u1ef1 c\u1ed9t ph\u00f9 h\u1ee3p v\u1edbi c\u00e1ch truy v\u1ea5n th\u1ef1c t\u1ebf. N\u1ebfu kh\u00f4ng, index c\u00f3 th\u1ec3 kh\u00f4ng \u0111\u01b0\u1ee3c t\u1eadn d\u1ee5ng hi\u1ec7u qu\u1ea3.<\/li>\n<li><strong>Theo d\u00f5i v\u00e0 t\u1ed1i \u01b0u index \u0111\u1ecbnh k\u1ef3:<\/strong> Vi\u1ec7c ki\u1ec3m tra v\u00e0 t\u1ed1i \u01b0u c\u00e1c index th\u01b0\u1eddng xuy\u00ean gi\u00fap \u0111\u1ea3m b\u1ea3o ch\u00fang v\u1eabn mang l\u1ea1i gi\u00e1 tr\u1ecb v\u00e0 kh\u00f4ng g\u00e2y t\u1ed1n k\u00e9m t\u00e0i nguy\u00ean do chi ph\u00ed b\u1ea3o tr\u00ec cao.<\/li>\n<li><strong>\u01afu ti\u00ean s\u1eed d\u1ee5ng covering index khi c\u00f3 th\u1ec3:<\/strong> N\u1ebfu \u0111i\u1ec1u ki\u1ec7n cho ph\u00e9p, covering index gi\u00fap t\u0103ng hi\u1ec7u su\u1ea5t truy v\u1ea5n b\u1eb1ng c\u00e1ch ch\u1ee9a \u0111\u1ea7y \u0111\u1ee7 c\u00e1c c\u1ed9t c\u1ea7n thi\u1ebft trong c\u00f9ng m\u1ed9t index duy nh\u1ea5t.<\/li>\n<\/ul>\n<figure id=\"attachment_36821\" aria-describedby=\"caption-attachment-36821\" style=\"width: 800px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"size-full wp-image-36821\" src=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Luu-y-khi-su-dung-index-trong-database.jpg\" alt=\"L\u01b0u \u00fd khi s\u1eed d\u1ee5ng index trong database\" width=\"800\" height=\"500\" title=\"\" srcset=\"https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Luu-y-khi-su-dung-index-trong-database.jpg 800w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Luu-y-khi-su-dung-index-trong-database-300x188.jpg 300w, https:\/\/interdata.vn\/blog\/wp-content\/uploads\/2025\/12\/Luu-y-khi-su-dung-index-trong-database-768x480.jpg 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption id=\"caption-attachment-36821\" class=\"wp-caption-text\">L\u01b0u \u00fd khi s\u1eed d\u1ee5ng index trong database<\/figcaption><\/figure>\n<h2><span class=\"ez-toc-section\" id=\"Su-dung-index-trong-database-nhu-the-nao-cho-hieu-qua\"><\/span>S\u1eed d\u1ee5ng index trong database nh\u01b0 th\u1ebf n\u00e0o cho hi\u1ec7u qu\u1ea3?<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p>D\u00f9 index \u0111\u00f3ng vai tr\u00f2 quan tr\u1ecdng trong vi\u1ec7c t\u0103ng t\u1ed1c truy v\u1ea5n v\u00e0 t\u1ed1i \u01b0u kh\u1ea3 n\u0103ng t\u00ecm ki\u1ebfm trong database, nh\u01b0\u1ee3c \u0111i\u1ec3m c\u1ee7a n\u00f3 l\u00e0 ti\u00eau t\u1ed1n th\u00eam dung l\u01b0\u1ee3ng l\u01b0u tr\u1eef. V\u00ec v\u1eady, vi\u1ec7c t\u1ea1o index cho c\u00e1c c\u1ed9t c\u1ea7n \u0111\u01b0\u1ee3c c\u00e2n nh\u1eafc k\u1ef9 l\u01b0\u1ee1ng \u0111\u1ec3 tr\u00e1nh l\u00e3ng ph\u00ed t\u00e0i nguy\u00ean.<\/p>\n<p>D\u01b0\u1edbi \u0111\u00e2y l\u00e0 m\u1ed9t s\u1ed1 l\u01b0u \u00fd gi\u00fap b\u1ea1n s\u1eed d\u1ee5ng database index hi\u1ec7u qu\u1ea3 h\u01a1n:<\/p>\n<ul>\n<li>N\u00ean t\u1ea1o index cho c\u00e1c c\u1ed9t th\u01b0\u1eddng xu\u1ea5t hi\u1ec7n trong <strong>WHERE<\/strong>, <strong>JOIN<\/strong> v\u00e0 <strong>ORDER BY<\/strong><\/li>\n<li>S\u1eed d\u1ee5ng <strong>index prefix<\/strong> ho\u1eb7c <strong>multi-column index<\/strong> trong MySQL; v\u00ed d\u1ee5, n\u1ebfu \u0111\u00e3 t\u1ea1o <code>Index(first_name, last_name)<\/code> th\u00ec kh\u00f4ng c\u1ea7n t\u1ea1o th\u00eam <code>Index(first_name)<\/code><\/li>\n<li>\u00c1p d\u1ee5ng thu\u1ed9c t\u00ednh <strong>NOT NULL<\/strong> cho c\u00e1c c\u1ed9t \u0111\u01b0\u1ee3c \u0111\u00e1nh index<\/li>\n<li>Kh\u00f4ng n\u00ean d\u00f9ng index cho c\u00e1c b\u1ea3ng c\u00f3 t\u1ea7n su\u1ea5t <strong>UPDATE<\/strong> ho\u1eb7c <strong>INSERT<\/strong> cao<\/li>\n<li>Tr\u00e1nh t\u1ea1o index tr\u00ean nh\u1eefng c\u1ed9t c\u00f3 gi\u00e1 tr\u1ecb thay \u0111\u1ed5i li\u00ean t\u1ee5c<\/li>\n<li>S\u1eed d\u1ee5ng c\u00e2u l\u1ec7nh <strong>EXPLAIN<\/strong> \u0111\u1ec3 bi\u1ebft MySQL th\u1ef1c thi truy v\u1ea5n nh\u01b0 th\u1ebf n\u00e0o, bao g\u1ed3m th\u1ee9 t\u1ef1 join v\u00e0 c\u00e1ch c\u00e1c b\u1ea3ng \u0111\u01b0\u1ee3c li\u00ean k\u1ebft, t\u1eeb \u0111\u00f3 d\u1ec5 d\u00e0ng t\u1ed1i \u01b0u c\u00e2u l\u1ec7nh v\u00e0 l\u1ef1a ch\u1ecdn c\u1ed9t c\u1ea7n index h\u01a1n.<\/li>\n<\/ul>\n<\/article>\n<p>Qua b\u00e0i vi\u1ebft n\u00e0y, InterData hy v\u1ecdng b\u1ea1n \u0111\u00e3 c\u00f3 c\u00e1i nh\u00ecn to\u00e0n di\u1ec7n v\u00e0 s\u00e2u s\u1eafc v\u1ec1\u00a0index trong database l\u00e0 g\u00ec. Index kh\u00f4ng ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 m\u1ed9t c\u00f4ng c\u1ee5 k\u1ef9 thu\u1eadt, m\u00e0 l\u00e0 m\u1ed9t ngh\u1ec7 thu\u1eadt c\u00e2n b\u1eb1ng gi\u1eefa t\u1ed1c \u0111\u1ed9 \u0111\u1ecdc v\u00e0 t\u1ed1c \u0111\u1ed9 ghi, gi\u1eefa hi\u1ec7u su\u1ea5t truy v\u1ea5n v\u00e0 chi ph\u00ed l\u01b0u tr\u1eef.<\/p>\n<p>Vi\u1ec7c s\u1eed d\u1ee5ng index th\u00f4ng minh s\u1ebd bi\u1ebfn h\u1ec7 th\u1ed1ng c\u1ee7a b\u1ea1n t\u1eeb m\u1ed9t c\u1ed7 m\u00e1y ch\u1eadm ch\u1ea1p tr\u1edf th\u00e0nh m\u1ed9t si\u00eau xe t\u1ed1c \u0111\u1ed9. Tuy nhi\u00ean, index c\u0169ng l\u00e0 m\u1ed9t con dao hai l\u01b0\u1ee1i. H\u00e3y lu\u00f4n ph\u00e2n t\u00edch k\u1ef9 d\u1eef li\u1ec7u, h\u00e0nh vi ng\u01b0\u1eddi d\u00f9ng v\u00e0 tu\u00e2n th\u1ee7 c\u00e1c nguy\u00ean t\u1eafc &#8220;N\u00ean v\u00e0 Kh\u00f4ng N\u00ean&#8221; m\u00e0 ch\u00fang t\u00f4i \u0111\u00e3 chia s\u1ebb \u0111\u1ec3 \u0111\u1ea1t hi\u1ec7u qu\u1ea3 t\u1ed1i \u01b0u nh\u1ea5t.<\/p>\n<p>N\u1ebfu b\u1ea1n c\u00f2n b\u1ea5t k\u1ef3 th\u1eafc m\u1eafc n\u00e0o v\u1ec1 t\u1ed1i \u01b0u database ho\u1eb7c c\u1ea7n t\u01b0 v\u1ea5n v\u1ec1 c\u00e1c gi\u1ea3i ph\u00e1p l\u01b0u tr\u1eef hi\u1ec7u n\u0103ng cao, \u0111\u1eebng ng\u1ea7n ng\u1ea1i \u0111\u1ec3 l\u1ea1i b\u00ecnh lu\u1eadn b\u00ean d\u01b0\u1edbi. Ch\u00fac c\u00e1c b\u1ea1n \u00e1p d\u1ee5ng th\u00e0nh c\u00f4ng v\u00e0 c\u00f3 nh\u1eefng h\u1ec7 th\u1ed1ng c\u01a1 s\u1edf d\u1eef li\u1ec7u v\u1eadn h\u00e0nh si\u00eau t\u1ed1c!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Khi l\u00e0m vi\u1ec7c v\u1edbi c\u01a1 s\u1edf d\u1eef li\u1ec7u, kh\u00f4ng \u00edt ng\u01b0\u1eddi g\u1eb7p t\u00ecnh tr\u1ea1ng truy v\u1ea5n ch\u1eadm, \u0111\u1eb7c bi\u1ec7t l\u00e0 khi d\u1eef li\u1ec7u ng\u00e0y c\u00e0ng l\u1edbn. D\u00f9 c\u00e2u l\u1ec7nh SQL kh\u00f4ng ph\u1ee9c t\u1ea1p, th\u1eddi gian ph\u1ea3n h\u1ed3i v\u1eabn k\u00e9o d\u00e0i khi\u1ebfn hi\u1ec7u su\u1ea5t h\u1ec7 th\u1ed1ng b\u1ecb \u1ea3nh h\u01b0\u1edfng. \u0110\u00e2y c\u0169ng l\u00e0 l\u00fac nhi\u1ec1u ng\u01b0\u1eddi b\u1eaft<\/p>\n","protected":false},"author":11,"featured_media":36823,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[58],"tags":[],"class_list":["post-36816","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-server"],"_links":{"self":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/36816","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/comments?post=36816"}],"version-history":[{"count":2,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/36816\/revisions"}],"predecessor-version":[{"id":36825,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/posts\/36816\/revisions\/36825"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media\/36823"}],"wp:attachment":[{"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/media?parent=36816"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/categories?post=36816"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/interdata.vn\/blog\/wp-json\/wp\/v2\/tags?post=36816"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}